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Himoits of % ffiauam of <ompM»tti>t JSoologg

AT HARVARD OOLLBaB. Vol. XXI.

THE NORTH AMERICAN

CRINOIDEA CAMERATA.

By CHARLES WACH8MUTH and FRANK SPRINGER.

) ■

IN TWO VOLUMES WITH SIOHTY-THREE PLATEa

Vol. II.

CAMBRIDGE, U.S.A.:

Vtinteti for tiie iKtMitum. Mat, 1897.

*'-

ft '^ -'

■"';'Sr!

*fl*-. „-'i^

MEx\I01RS

OF THE

MUSEUM OF COMPARATIVE ZOOLOGY

AT

HARVARD COLLEGE.

VOL. XXI.

CAMBRIDGE, U.S.A. PRINTED FOR THE MUSEUM.

1897.

^1

il

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Univebsitv Press : John Wilson aku Son, Camuuidge, U. S. A.

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CONTENTS.

THE NORTH AMERICAN CRINOIDEA CAMERATA. Uy Ciiahles Waciismitii and Fbank Si-RlNOiiB. Chapter X. Page 301 to end.

^™3raw«Krr"^=' -■-■

i

\

I

Bltmous of tbc gluscum of (Comparatibc ^oblogg

AT HARVARD COLLEUE. Vol.. XXI.

THE NORTH AMKIUCAxX

ClUNOlDExV CAMEUATA.

Uy CHARLES WACIISMCTII and FRANK Sl'RIN(ii:R.

IN TWO VOLUMES WITH EIOHTY-THREE PLATES

Vol. II.

CAMBrnDOE, U.S.A.:

iDvtntrti for Ujc Iflusrum.

M,\Y, 1897.

TAHLE OF CONTKNTS.

SYHTKMATIC

Vv.K Il,\TiirlMNI|).\K ilOI-rill)

Aimh-His (if tlie (Iciu'ni 3(il

Jiroldnuiil iiiul Googinpliii'iil Distil-

liiiUon a<!.1

IliitQcrliiiti's acn

lliitoi'i'lnns acC)

Kii'tmuciimis ;)n;)

AlliJ|ii(isiill(K'riiiiiH lofi

KlllrOclKKTlllll.S |(IS

Dizyfjciciiiiiw .113

Loliocrliiiis .i;!|

MncrocrliHis i ic

Doiyciimis i;,t

Aor .ilium |7o

Iliiminilcocriiiiis .|h|

AgiirlcociiiiiiH iHij

Aciieuuiiiiiis 515

Coinpsocrlmis 51 fi

l'eiici:linriiiiiti's riiy

IVi'ii'clinciiiiiis .iio

Mej,'isl(X'iiiiii.i 532

(ieiiniTOfrliiiis 517

AcTINlPCIilNlliAK o.JO-CIl

Annlvsis ofllic Cii'iicin 550

Gc'olojjiciil and (u'(ij;iniiliicnl Diatri-

1)111 ion , . . 5,')1

iVctinocriiiiia .•j.io

Stc^iinocrimis 57,s

Aiiipliornciliiiis 586

I'v.i: .V.iJ r,i)i) r,;'i; (',37 Till

i;ii

111;) 1:17 7r.i 7;ii)

I'AUT (ruiiliiiiie,!),

ril\Helrl('|ili||u

t'llftuCl'MIIW

'I'l'li'lociiiiiig

Stiotocilmw

I'l.ATYl lllMiiAi.; (;(o.

Analysis of tlie Gi'iiem

(•c'ol(>j,'l('iil and (iioginplikal DUlii- liiitlon

I'laUfriiiiH

iMIthllloCTillllS

.MMI'Sll|lillc|l||UH

Ciii-ilyloi'iiiiiis 7;;5

Cofcocrlniis 7;),s

IIf.xachimiiak 7I1-K(i2

Analysis of tlio (irniTu 7|i

(Ic'olo^^k'al anil (icoy:iniiliical Dislrl-

biitloii 7|-_)

Ilcxiicilmis 711

Aitlirncaiitlia 717

Dicliocriiiiis 7,-,;j

CiunptocriiMis 77;i

Talai'oui'iiius 7,s|

rti'iotocrlniis 701

AciiormxiiiAK k03-,h1()

(U'olofjifal ami Gt'ograpliical l)l>lii-

liiition ■ 803

Acrocriniis hii,-)

Ini'Ex 813

r

BATOCEINIDyE W. and Sp.

MoNocYLic. The lower nnAciiiALs with well defined interbraciiials between them

FORMING AN IMPORTANT PART OP THE DORSAL CUP. RaDIALS IN CONTACT EXCEPT AT THE POSTERIOR SIDE, WHERE THEY ARE SEPARATED BY A IlEPTAGONAL ANAL PLATE, WHICH IS FOLLOWED BY A SECOND ANAL BETWEEN TWO INTERBBACHtALS.

Analysis of the Genera.

f

I.

Ventral disk hiohly differentiated : the plates large and

HEAVY, FORMING A niGM) INTEGUMENT. AkMS NOT BRAXCII-

INO BEYOND THE CALYX BaTOCRINITES.

A. Arms iilserial ; iiasals three.

1. Anus at the end of a tube.

a. Interbraclnah ne/xinitedfroii) interambulacrals by

an arr/i ofbrnchinh. Calyx bitiirbinato. Arms sliort, cquiilistant ; anal tube very long and central; respiratory pores

twenty, well defined B(tt(ier!nii.*.

Anns long, paddle-shaped ; anal tube exccn- tric; respiratory pores twenty . . . Kivtmocrhiiis

Calyx conical, dorsal cup almost flat, ventral disk greatly predominating in height; anal tube central ; respiratory pores twenty Uloprosallocrlmis.

b. Interbrni'hUds ronnerfeil trith interomhulaerah.

Arms arranged in groups, the openings di- rected upward ; anal tube large, central. Calyx pyriform to wheel-shaped ; arms

twenty; respiratory pores not visible . LoborriiiKn.

Calyx elongate, biturbinato r subovoid; arms twelve to sixteen ; respiratory pores

ten • Macrocritius.

e. Interhrachiah in contact with interambulacrals at anal side only.

Calyx wheel-shaped ; anal tube very large, central ; arms short, single or paired ; re- spiratory poies twenty Eutrochocriniin,

46

362

THE CRINOIDEA CAMERATA OF NORTH AMERICA.

Calyx rotundato ; anal tube moderately small, about central ; arm openings twelve to twenty ; arms long, single or paired, often in the same species ; respiratory

jiores n(5t visible Dlxi/gocrimis,

2. Anus witiioi't a ti'iik.

a. Ctdyx lolled; arms arranged in groups,

Caiyx more or less elongate.

Arms heavy, one from eaeh opening.

Arms ten, recumbent on the dorsal cup ; pin- nules infolding Jiarrandeocrinnn.

Arms one only from each opening, erect,

rather heavy Aorocriniis.

Arms slender, paired ; upper arm joints spiniferous ; posterior oral and proximal radial dome plates extended into spines . Dorycrinus,

b. Calyx hi'misphcrk or pyramidal ,

Dorsal cup from very slightly convex to concave ; arms heavy. Orals and radial

dome plates prominent Agaricocrinus,

B. Arms uniserial.

1. BasALS THliKK. IxrEnliUArillALS NOT NUMEROUS. COL- UMN ROUND.

a. Arms delicate, joints ouneate, alternately arranged,

only interlocking at the tips Acacocrinus.

b. Arms hcaryfjuintx ijiMdrangiilar.

Arms ten Ilabrocrinns.

Arms more than ten (?) Desinidocriniis.

2. Basals four ; column quadrangular.

Arms slender, joints cuneate ; plates deli- cate .and highly ornamented. Interbrach- ials and interdistichals verj uimei-ous . Compsocrinus.

II. Ventral disk composed of small, irreoularly arraxgrd plates,

WITH or without ORALS. ArMS GENERALLY BRANCHING

beyond the calyx Perieciiocrinites.

A. Arms biserial from the calyx up. 1. Basals three ; anal area wide.

Calyx elongate, urn-shaped ; plates thin and elong.ate; arms grouped Orals indistin- guishable. The column with large cen- tral canal Perieciiocrinns,

Calyx depressed globose, plates short and heavy. Arms branching, given off in pairs, their facets contiguous ; or.als gen- erally represented ; central canal large . Megistocrinns.

Calyx low, strongly lobed at the arm regions, plates thin, highly ornamented. Arms arranged in clusters. Central canal of moderate size Gennmocrinus,

BATOCRINID^,

2. BasaU/our.

Dorsal cup similar to that of MegistocrinuK ; arms heavy, tlatteued on the bacii. . .

Geological and Geographical Distribution, Number of known species.

(Open figures indicate Aineriean ; those marked ( ), European.)

363

Abacocrinus

BATOCHIMIDd.

FORHATIOlf

Batocriuites.

Periefli<>-

t

crinites.

Approximate

kuropeau Equivalents.

s

a

m

A

i

a O

American.

a

1

1

a.

1

1

3

1

1

a a

•c

1

a U

I

d 1

5 14

a

rs a

a ■E

1

■g 2

s c

•c

10

i

a X

'i u

-i

s a •c

i

1

1

c

B

1

9

■c

1

a 1

s

.5

a

g

.S

1

Warsaw. Keokuk.

2

3

4

1

4

1

^

L'p. Burlington.

,1

9

4

3

3

3

2

5

8

1

1

.S

E

Low. Burlington.

3

a

9

6

3

I

3

3

4

1

1

to

1

Kinder hook.

3 O

Wavcrlv.

2

4

1

1

Chouteau.

—

1

—

—

—

—

—

—

1

Hamilton.

9

2

C

a .2

CO

Up. IIc'Mcrberg.

Eifcl

(3)

11 ■■1)

10

22

2 2

(19) (19)

(4) (4)

2 2

8 (16)

11

(16)

—

~;,

Niagara.

Wciilot'k. Ootlaiul.

4

32

(1) (1)

Hudson River.

1

Total species 20

I 153 3 1 (50)

19

19

10

6

12

(!)

2

(«)

liemarks. — The Batocrinidne and Actinocrinidne differ from the two preceding monocyclic families, Melocrinida) and Cnlyptocrinidte, in having a large anal plate separating the two posterior radials and resting upon the basals ; and as a consequence of this a hexagonal base, which is composed

«i>

w

1

364

THE CRINOIDEA CAMERATA OF NORTH AMERICA.

..^

<?

a ^>

Fio. IS. fifittfrrimtt.

f> = hiisals. /? = raclials, .r — sprcial nnni plate. *> --- supplementary anal ibr — iittcrhracliials.

in all but two of the known genera in both families of three equal plates. The orientation of these plates is uniform throughout both families, viz. : the interbasal sutures are directed toward the anal plate and the two antero-lateral radials. The anal plate in the Hatocrinidio is heptagonal,

and is followed by three plates in the first interbrachial row, viz. : a second anal and two interbrachials ; whereas in the Actinocrinidon the anal plate is hexagonal, and is followed only by the two interbrachials, — there being no second anal. AVe regard the pre.'^once of a second anal within the first row of inter- brachials as of considerable morphological im- portance. It is represented without exception from the Lower Silurian to the close of the Devonian in all monocyclic Camerata in which anal plates occur; in the Kinderhook, for the first time, we find both forms together : the Actinocrinoid with but two plates above the first anal, and the Batocriuoid with three.

When there are three basals, the superior edge of the basal cup is nine- angleil, six of the angles being salient, the others retreating, and the suture lines are directed to the middle of the two antero-lateral radials and the anal plate. By this arrangement two of the radials are heptagonal. and the three others hexagonal. In Cunqjisocrimis with four basals, the posterior and anterior basals are pentangular, the two others quadrangular, the anterior radial hexangular, all others heptangular.

Tlie alternate bifurcation of the arms from the two main branches of the rays, which is characteristic of the Actinocrinida?, forms another well, marked distinction between the two families, and is also very constant. Among the Batocrinidic this mode of bifurcation occurs only in Gainwo- crintts from the Upper Devonian, but there it goes along with a second anal ; and we must regard this genus as a transition form toward the Actinocrinidce. The paired arm structure also, although not a constant character, occurs only among the Batocrinidfc ; never among the Actino- crinida;. Another significant fact, tending to confirm the separation of the two groups as distinct families, is that ,so far as known the Batocrinidaj disappear in Europe with the dawn of the Carboniferous — except perhaps

■4M

BATOCKINID^K.

365

Mcijintocriiius, of which a species may possibly exist in the Mountain Lime- stone of Enghmil — iind are replaced by the Actinociinida). This is also the case in the western territories of the United States. At Lake Valley, New Mexico, anionic many iiundred Camerate Crinoids collected I'rom the horizon of the Burlington group, we found only one or two straggling Batocrinoids.

The genera for which this family is proposed, with the exception of Compsacrimis, have been heretofore ix'ferred by us antl others to the Actinocrinida3, and most of the species were originally described under Aclimcrlnm. Even the genus liatucrinus was not accepted by the earlier writers. This was no doubt largely due to the fact that Casseday in describing the genus overlooked the arrangement of the plates of the anal area, which, as we think, forms the principal distinction between the two groups. lie only alluded to the meeting of the distichals and palmars over the interbrachials, and the separation of the latter from the plates of the ventral disk. Tiie importance of the structure of the anal area was pointed out by us in tiie Revision, Part II., p. lot), when we recognized the genus liatommta, but at that time we only made it the type of a subgroup under the Actinocrinida).

As now defined, the Batocrinidaj are by far the largest family of the Camerata, and tiiey have a greater stratigraphic range than any except the Rhodocrinida-, — ap|)enring first in the Hudson River group of the Lower Silurian, and continuing into the War.saw. The family consists of eighteen genera, of which twelve, so far as known, are restricted to America, and six to Europe ; ' while Perurhocriims and M<-(jlsfocr!inis occur on both sides of the Atlantic. Of these genera two hundred and three good species have been recognized, — fifty of tlicm coming from Europe and one hundred and fifty-three from North America.

There are in Kurope two other genera which probably ought to be placed in this family, — Poli/peltes Angelin, and Sp>/ridmri/ni.s Oehlert ; but as the arrangement of the two or three proximal rings of plates in the calyx cannot be made out in the specimens, they may possibly belong to the Melocrinidoa.

We have subdivided the genera of this family into two sections, which will considerably facilitate identification, viz. : —

1 1

J

: 1

*.

T

366

THE CRINOIDEA CAMERATA OK NOUTU AMERICA.

A.

Those in wliich the ventral disk is hiylily difFcrentiated, thn plates being large and heavy, and in which tlie arms <!(> not branch beyond a minute axillary at the arm opening .

BATOCKINITES.

B.

Those in which the ventral disk is composed of small, irregu- larly arranged plates, and the arms generally branch after becoming free I'EIUECIIOCRINIXES.

A. BATOCRINITES.

BATOCRINUS Casskdav.

1S51. Casskdav; Zcitsclir. dor Dculsch. Grol. OcscUsch., Vol. VI., p. 237.

1857- PliTKT ; Traill- ilc I'liluciiil., Viil. IV., p. 321.

1S02. DiJARDiN mill Uri'E ; llisl. niitiiri'lle ilcs Zimplijtes Ecliiuod., p. 142.

18()5. Mkkk ami ^VouTll^:^• (Subgenus of Aeliimervius) ; Proceed. Acail. Nnt. Sci. Phila., p. 153.

ISCiO. Mt;t:K ami WoiiriiKX (Suligonus of Acliiioeriiiun); Gcol. Rep. Illinois, Vol. II., p. 150.

ISfl!). Mekk and Wuktiikn j rioci-eil. Acnd. Nat. Sci. I'liiln., p. 350.

1S73. Mf.ek and Wiiktiien ; Geol. Hep. Illinois, Vol. V., p. 301.

1S78. W. and Sp. ; Proeced. Acad. Nat. Sei. Pliilii., p. 329.

1879. ZlTTKi, ; llandb. dcr Palirontologie, Vol. I., p. 370.

18SI. W. anil Sr. ; llevision Palieocr., Part II., )). 102 (Proceed. Acad. Nnt. Sci. Pbila., p. 33G).

1885. Stkixmann ; Elcmentc der Pahvontologie, Part I., p. 157.

1890. S. A. M11.1.KK ; North Anier. Geol. and Palicont., p. 227.

1892. S. A. JIii.i.EU ; Adv. Sheets of the 18lh Geol. Hep. Indiana, p. 23.

Sfn. Aciiiinrriiiiis (in part) Siu;maiii), Hall, White, McCiiesxey, and Meek and Wortiien prior to 1805, Qi-ESSIEDT as late as 18>5.

Syn. Uperocriiiiis (in pari) Meek and WonTiiEX, 1S05; Proceed. Acad. Nat. Sci. Pbiln., p. 153.

Calyx biturbinate to subglobo.<e ; the rays not lobed. Plates heavy, the surface more or less convex and frequently nodo.se, but otherwise not orna- mented. Basals three, proportionally large, forming a hexagonal cup thickened at the lower margin, and generally projecting laterally. Eadials very large. Co.stals two, small, quite frequently anchylosed ; the first qua- drangular, almost linear; the second pentangular. Distichals and palmars as large as, or larger than the cost.als. Palmars are always represented, except occasionally in the anterior ray. The posterior rays frequently have post-palmars, which do not occur in the other r.ays. Arm openings equidis- tant, directed horizontally. Respiratory pores twent}-, two above each interradius, and two to each interdistichal space ; placed at a somewhat higher level than the arm openings. Arms twenty to twenty-six; in species with more than twenty arms the extra number is divided between the two

«iP

T

BATOCRINID^K.

3G7

•V

posterior rnys. The nrms are simple, very short, slightly incurving, nntl rounilud on the buck (never spatulate) ; the pinnules stout, deep, closely packed, and fattened at their lateral faces. Iiiterbrachials separated from the interainbulacral pieces by the overarching palinars, which form a con- tinuous series around the calyx ; the four regular sides have rarely more than three, of which the first is very large, those of the second row being small, while some species have but one. The anal plate is succeeded by three large pieces, and these variously by one, two, or three interbrachial plates. There are neither intcrdi.stichals nor interpalmars. Ventral disk convex ; the plates of nearly uniform size, except the posterior oral, which is larger, more convex, and forms the base of the anal tube on the anterior side. Anal tube central, heavy and long, often reaching twice the length of the arms. Column stout, round ; the axial canal small and pentangular.

Dlntrihitlon. — Batocrhms ranges from the Kinderhook to the lower part of the St. Louis group, and, so far as known, is restricted to America.

Type of the genus : Batocrhms icomhwtyhis Cass.

JhiiKirks. — The genus Batocrinus was not accepted by Hall, White, or McChesney, who referred the respective species to Actinocrlnm. Meek and Worthen were at first inclined to give it only subgeneric rank, but in 1873 recognized it as a full genus, in which they were followed by us in 1881. As the best distinction between Batocrlmis and Actimcrinm, Casseday pointed out the closure of the fixed upper brachials over the interbrachial plates, and no doubt this is a most excellent character, and holds good in the typical species of Casseday. But unfortunately, among the species w hich Meek ond Worthen afterwards referred to the genus, there are quite a number in which this rule does not apply, and these species, which have good generic characters of their own, have been eliminated by u.s, and made the types of independent genera. Batocnnus, as now restricted, differs from ErctmO' criniis in having short cylindrical arms in place of paddle-shaped ones, and in the greater length of the anal tube. Eutrochocrinus and Dkygorrinm differ from both of them in the tendency of the arms to double from the same opening. Macrocriniis and Lohocrimis have the rays lobed and the arms arranged in groups ; in the former the anal tube is large and central, in the latter short and excentric. The arms of Batocrinus are sometimes slightly flattened towards the tips, but never paddle-shaped like those of Erctmoeriims.

♦ II

« f

3C8

THE CRINOIDEA CAMKRATA OF NORTH AMERICA.

BatoorinuB ioosidaotylus CAssKnAv. Plate XXVII. Figs. 3a, b, c.

-Casskdav; Kuilsclir. il. DcuUcli. Gcol. GescIUcb., Vol. VI., p. 238, Pktc

1861. Biilorriiitt) irosiifar/ylm -

i, Fift*. 1, la-c.

1957. B,ilo,-ntiiiii i,'o,iiA/,7y«.i — PiCTET i Trnlli! dc Piiliioiil., Vol. IV., p. Mi, Plate 101, Fig. 6. 1S67. Adiiiiifiiiiiis (Hiil(irriiiii') ironidiicli/lim — M. nml W, ; (Jcol. Ucp. Illinoin, Vol. V., ]). 367. 1S81. Jln/ui-rinm imiiliirt^lm — \V. mid Sp. ; Itcvisioii I'lilimcr., I'url 11., p. 1(10 lS8j. Arliiinfriiiui ieoiidaetj/liu — Quensteht j lluiidl). dcr I't'trefnctciikunde (:!lo Aiillngc), Plate 77.

KiK. 3. 1892. KnlocriHU! irotii/nr/f/iii — S. A. MiMElli Adr. Shcols (Icol. Hep. Iiidliinn, p. 21, PInle 4, Figs, l-.'i.

Calyx nearly ii.s wido as liigh. Dorsal cup rnrely more than half the height of ventral disk, low saucer-shaped, with a protuberant hose ; plates heavy, slightly convex, their .surface smooth or ob.scurely granular.

Basal cup projecting conspicuously beyond the level of surrounding plates, almost circular in outline ; the median part deeply depressed for the recep- tion of the column ; central perforation subpentangular. Eadials ."hort, partly hidden from view by the overhanging rim of the basals. First costals quadrangular, three times as wide as long, narrower than the second. Disti- chals two, a little larger than the costnls. Palmars three, increasing in width upward and placed in longitudinal series, which are separated by well defined grooves. Arm openings facing laterally, forming a continuous row around the calyx. Arms four to each ray ; their structure not known. Inter- brachials three (rarely foin*) to the intcrradius; the first much larger than the other two. The anal plate, which resembles the radials, is followed by three plates, and these by one or two. Interbrachials not connected with the plates of the tegmen, the higher brachials being in lateral contact. Ventral di.^k conical, passing gradually into a strong, almost central tube. The larger plates, as a rule, are extended into thorn-like projections, and are surrounded by smaller, slightly convex pieces. Orals quite excentric, four of them spinous, the posterior one merely convex. The radial dome plates, which are represented by plates of a first, second and third order, are .ilso spiniferous. Anal tube long, heavy, and composed of convex pieces, among which larger thorn-like plates are scattered at intervals. Column round.

Horizon ami Locality. ■ Barren Co., Ky.

Warsaw limestone ; Spergen Hills, Ind., and

\0

IlATOCRIXID.i:.

360

Batoorlnua Irregularis Carnruay. riiUc XXriI. Figs. 4(1, /'-, nnd c.

1851. Cassedav 1 Deiilsclic Ouol. Ocscllscli., Iliiiid VI., p. 2 10, I'liito J, I'igs. 2a, i, e.

1807. Mkkk Hiul WoiiTiiKX ; (Icol. Hip. llliinils, Vol. V., p. 3117.

1881. W. nnd Sp. ; llivi'.iim I'iiIiukt., I'lirl 11.. p. Hid.

Wii. S. A. MiLLKii; Adv. Shtcis ISlli Hep. Gml. Siirv. liidiiiiin, p. 20, I'lutu I, Y\i;f. 0-9.

Resembling the preceding species, but rendily (liHtingui.«)iod by it.s smaller size, more elongate form, much greater depth ol' dor.sal cup, by having a less number of arms, and the absence of spiniferoiis plates in the togmen. Sin'- faco of plates smooth or slightly wrinkled, the radial ones transversely ridged ; suture lines distinct.

Basal cup projecting, circular in outline, deeply excavated for the attach- ment of the column. Hadials short, considerably wider than the costids. Costals small, quadrangular, twice as wide as long ; succeeded in four of the rays by 2 X 2 distichals, which resemble the costals in form and size, aiul support 2X2X2 fixed palmar.s. In the anterior ray there are two rows of three successive distichals followed by the free arms. Arms eighteen, the aml)ulacral openings directed horizontal!}'. Interbrachial plates three ; the first larger, supporting two plates in the second range. The anal piece is succeeded by three plates, and one above. Tegmen high-conical, higher than the dorsal cup; composed of comparatively few, large, tumid plates. Anal tube stout, almost central ; constructed of strongly nodose pieces. Arms and colunm unknown.

Horizon and Locality. — Same as last.

f I

Batocrinus subcequalis (ArcCnEsxEv). Plate XX17II. Fiys. 7a, b; Sa, h, and 9.

18B0. Arlinoerin«> mbirqualia — McCiiesney, Dcspr. Pnl. Fnss., p. 17.

1S70. Arliiiorriiim siibitqunlin — McCiiksxky; Chicngo Acnd. Xiil. Sci., p. 13, Plftto 5, Fig. 7. 1873. JIu/ucriiiiis siiliirqiialia — Mekk nnd Wobtiiex; Cinil. H(^p. Illinois, Viil. V., p. 307. 1881. Biilocriiim lubitjmlis — AV. and Sr. ; (S\tt. o! JlutocriiiKs (/ixroidriiii), \lc\\iion I'alicocr., Tart II., p. 160. Syn. .if/iiioi-riniit r/(.(CoiV/«« — IIam.; 1S58, Geol. Hep. lonn.Vnl. I., Part IT., p. 501. Syn. Jia/oeriniii discoic/eus — Meek and WniiTiiEx; Gcol. Hep. lllinnis, Vol. V., p. 367, and Vihh-

field; Mem. Amcr. Mns. Nat. Hist., lS93j Vol. I., p. U, Plate 1, Figs. 19, 20. Syn. AcliHocriiiHt formoaua —\Iki.\., 1S60; Suppl. Gcol. Hep. Iowa, p. 30. Syn. 7)i/fo(Ti/;Hs/un»ojw — Meek and Worthen; 1873; Geol. Ilrp. Illinois, Vol. V., p. .W. 8yu. Bntocriiius ifjiiaiilu — S. A. MiiLEB, 1S91 J Geol. Surv, Missouri, Bull. 3, p. 25, Plate 5, Figs. 13, U, 15.

47

370

THK CIIINOIDKA CAMKRATA OF NORTH AMKRK'A.

Calyx somewhat bituiliiiiato, ns wiilc as Iii^li. Tlie dorsal cup larger tliaii tlie ventral di.'-k; Hides eximnding gradually to tlie arm bases and forming nearly a straight line. I'hites nodose, except the first costals wiiieh arc generally Ihit.

Base more tlian twice as wide as high, hcxangular ns seen from the bottom; the interbasal suture lines distincily grooved ; column facet deeply <lepressed. liadiiils wider than long, widest at two thirds their height, exca- vated at the upper edges. Costals small, both together very little nioro than half the si/o of the radials ; the first linear ; the second a little longer and wider in the (ijjper part. Distiehals two, except in the divisions facing the anal side, in which there is hut one, which is axillary. Palmars 2 X 20; but while those approaching the posterior side l)ifurciite again, the others are followed directly by the free arms. Arm facets concave, arranged in a contiuiums row around the calyx. Arms twenty-two, short, almost of e(|ual width to their tips. Pinnules closely packed together, long, deep, and flattened at the sides. Regular iiiterbrachials consisting of one largo plate, sometimes followed by one or two smaller ones; the former extending to the top of tho first distiehals and even to the pnlmars. Anal plate consider- ably hijrher than the radials and succeeded by three large plates, and these by a single one. Ventral disk subconical, plates tubcrculose, pointed at the top. Orals and first radial dome plates larger than tho intervening supple- mentary pieces, which are quite irregular in form and size. Anal tube very long, sometimes extending .several inches be^'ond the tips of the arms; com- posed of tumid plates. Colunm constructed of rather large joints with rounded edges ; the internodals somewhat tho narrowest.

Horizon and LocuViti/. — Lower Burlington limestone ; Burlington, Iowa, nnd in rock of tho same age in Southern Missouri.

Tiipc in tho (Worthen) Illinois State collection, Springfield.

linnarh. — There is not the least doubt ilmt Actliiocrhuis disroukus nnd A.formoms, both described by Ilall, are identical with this species. The former name has priority, but, being described from a crushed specimen, nnd neither the name nor the description giving a correct idea of the species, wo are compelled to adopt McChcsney's name. The form described as AclbiO' crinus formostis differs only in the less convexity of the plates.

•%!

I

«s

IIATOCUINID.K. U7l

Batoorinus ooqualla (IIm.i.). I'kk XXVIII. Fijx. -,,(',.

IS.'iS, .lrliiin<-rliiH> ,i'/ioi/ii — Hai.i.', ftcol. Iti-p. lown, Vol. I., I'lirl II,, p. .'flj, I'liitc 11, Vif^tt. I,/, li. lS7;t. /lii/,j(Vinuii in/«ii/i.i — M. niiA \\.; (lc<il, I(i|i, Illiiioi<i, Veil. V., p. ati?. ISSl. Hiitm-riiiuii (tiiuidii — \V. aiul !S|'. i Ui'ii^inri I'liliincr,, I'liU II., p. 105.

Svii, .li-liiiiicriiiiii iliirit — IJAI.r., Illll ; I)(■^'(•r. New Spec. Ciiii., p, 13.

Sjii. Ilii/uiviiiui iliirit — XI. mill \V. I Ciuiil. Hep. Illiuiii», \'<il. V., p. ;i(17.

Closely nllii-'il to tlio prt'ct'ding HpceicH, but (lilTorinj.' in tlio grcntor niiniltcr of nrinx. Cnly.x bitiiibinato, tnmcnlo iit the bottom ; the iloMil cup a littlo liij^lier tlinn the vcntriil disk ; tlic niiles abruptly spreading to the arm bases, wliicli are directed horizontally ; the plates smooth, hi;,'hly convex.

Huso short, excavated for tlio reception of the Cfduuin, the intcrbasal Hiitnres deeply grooved, giving to the lower end a trilobate outline. Itadials smaller thiin the basals, from once and a half to twice as wide as long, First costaLs less convex than the surroiniding plates, (piadrangular, variable in size, sometimes but half the width of tliL rndials and very short. Second costals wider and longer than the first. Distichals 2 X f2 ; supporting in four of the rays two rows of three plates, and these four arms to the ra^'s. In the two posterior raj's, which have from six to ."'even arms, liolh outer distichals of the rays support an axillary palmar, which is followed by 2 X 2 post-palmars ; while the two inner distichals support but 2 palmars. When there are seven arms, one of the post-palmars is nlso axillary and gives off two arms instea<l of one. Anns .short, cylindrical, biserial from their bases ; the plates short. Pinnules long. Regvdar intci brachials two or three, the first verj' large. The anal area consists of five plates ; the anal plate, which is larger than the radials, is succeeded by three ]>]ates hi the second row. and a small piece above. At nil sides the interbiiicliial plates are .separated froMi the dome plates l)y the ])ahnars, and post-palmars respectively, wiiieii form together with adjoining distichals and costals around the plates of tlie anal area a well defined semicircle. Ventral disk conical, gradually passing into the anal tube ; the plates strong and convex. The orals and ambulncral plates are much larger than the intervening ones, which latter are com- paratively small and numerous at the posterior side. Anal tube central, its plates slightly tumid. Column similar to that of the preceding species.

Ilorhon and Locality. — Lower Burlington limestone; Burlington. Town, and Southern Missouri.

I'ljpc in the (Worthcn) Illinois State collection, Springfield.

i

I ■!,!

"t

! ■ Ji

872 rilK CIUNOIDK.V CAMKUAIA ok NOKIII A.MKUKA.

Bttoorinui quailllui (MrKK mi<i Wnidii.). l'tal> XXVlll. Fl>/».4a,b.

ISIlB. /((/A)rY/«i/» 7ii«.i///«« — MK>k mill WiiHTiiKNi I'liii'nd. Acnd Nut. 8ci. I'liilii., p. liSii nUu (liul,

lli'p. Illiuni>, Vi.l. V , |>. :iljtl, I'lair 5, V\)f. 1. 1881. ll,iim-nnu> i/«iiiillin - W. mill M'. j KLUaimi ruliciicr., I'liil 11., p. 107 (I'lornil. Aciiil. Niil. M.

I'lilU., p. :itl).

Height of tlio cnlyx oqiiiil to its width j tlio ventral (HhU ocoupying fully one liiiir. Doisiil cun wiilu at tlie liottom, riinidly Hproiuliiig lu-iir the iiiiu hnses, ho iih to plncj the upper i'oum of hrnchialM in a horizontal poxition. Plates extremely heavy ami evenly convex,

Dasal cup tiireu tiuiex as wiilo ns high, hexagonal, thickened at tlio lower end ; the interliacal sutures slightly indented ; the bottom deeply depressed for the reception of the column. Ihidials nearly twice as wiile as long, the upper face concave. First costal very small ; the second more than twice ns long as the lirst. Distichals two; followed by two rows of two palmara each, except in the division's fiu'ing the anal side, where the first disticlial is axillary and supports an axillary palmar, and this 2X2 post-palinars. Arms twent3-two to twenty-four, arranged at ecpial distances, openings directed horizontally. Interbrachials two, the up])er very small, arched over by tiio palmars. Anal plate a little narrower and longer tlian the radials, succeeded by throe good-sizeil pl:ites, and tlice by ii single one. Ventral disk highly convex, inllated near the periphery so that its siden project sometimes be- yond those of the dorsal cup. Orals and radial dome plates somewhat tu- berculous, and twice as largo as the surrounding pieces which arc merely convex. Anal tube very strong, composed of thick plates ; its length not known,

Jlorizon and Loraltf;/. — Lower Burlington limestone; Burlington, Iowa.

Ti/j/c in the Museum of Comparative Zoology.

Batoorinus lepidus (TIam.). P/ate XXVIII. Figs. 2 and 3.

ITjO. Aftinoi'riiim Ifpiilu.f — IIai.i,; Suppl. Geo). Rep. Inwn, p. .13.

ISSl. Bi/m-n/iiia hiiiilun— \\\ niiil Sh. ; Hcvisimi Paln-iwr., Purl II., p. Ifi7.

1893. Biilurrinus h'liiilun — \\ \mym.n : Mom. Anirr. Miis. Xnt. Hist., Vol. I., p. 10, Plnlc 1, Figs. 17, If.

A little larger than the two preceding species. Calyx wheel-shaped, abruptly spreading beneath the arm bases ; ventral disk depressed convex, with a central anal tube rising abruptly from the summit. Plates smooth,

\vi\

I»AI'0( HrNID.R.

S78

convex ; tlio mitiiro liiiux i^rnovud. nuMulH ftlioit, tlilfkoruMl nruiind their lowt-r rimrKiii'*, iiml Hli),'litly fxciiviitt'd for tin* iittiiclmu'iit (if the coliiinii. UudiiilM II litlh' widor than lon^, ('oiiciivu itt thu u[i|it'r t'acc, ContiilM corn* |)iiriitivi'ly hirgci' thiiii ill tliu proci-diiig npcciivM ; iiiiiidi'iingiihir mid iiiMitiin^iu liir; thu ML'coiid widur thnii tho (ii'Mt. DiNtiehiiU two (t>xcc>|)t towfird tlio iitinl Hide); thu iippur wider thiiii thu coNtid iixilhiry ; fullowud \>y two pidiiiiii-N, of which thv Hi'coiid is thu hirj^ur. Towiiril tht? anal Hide thcrt' i.-* hut oiiu di". tichitl, and thu Nucoiid pahiiar at thu outer (hvinions of tliu iii^'s HUpportH two post-pniiuarx, but only one lU thu innur HJdu, making five iirniH to oncli of tho posterior myn. Ann opuningn urraiigcil at ii<'aily u(|ual distanous ; directed liori/ontally. Respiratory pores large, phiced a iiltie nhovo the arm bases. Anns heavy, short, slijfjitiy llatteiicil on the baeit ; roiiiposcd of two serii'S of short joints. Interbrachials two; tiie llrst exteiidiiij{ to the lower sloping faces of thu first distichais. Thu palniars in lateral contact except at tho posterior side, where only the post-palinars connect laterally, Anal piato loMj(er than the railials; followed by three and two plates. The plates of tho ventral disk vary in m.o ; thu oralH and radial dome plates bein^r nioru than twicu ns large as thu intervening piuces, which nre quitu niimurous. Length of anal tiibu not known.

JIiin'~'iii mill f.iini/if//. — fAJWcr Burlington limestone ; Burlington, lowii and Southern Missouri.

Ti/jie in thu (Worthen) Illinois Statu collection.

Batoorinua Calvini l!n\vi.i:v.

r/iiti: XLVI. Fl'js. Su, h.

ison. Itinvr.Kv; Aiiicr. (i.dln^ist, Vul. V., |i. 1 Irt.

Calyx greatly deprt»ssod, almost twice as wide as high, with n sharp edge around tho margin. Dorsal cup low bowl-shaped, a little higher than llio ventral disk. Plates very slightly convex ; the .suture line.s distinct, but not actually grooved.

Basals quite small, forming a pentagon without ru-unturing angles ; tho columnar concavity narrow but rather deep. Radials as largo as both cos- ta!s together, wider than high. First costals quadrangular, twice ns wide as high ; tho second pentangular, wider than the first, but narrower than tho radials; tho upper angle quite obtn.se. Distichais larger than tho costals ; represented in four of thu rays by two scries of two plates, the upper ones,

i

i1:

\ '

f

vt

374

THE CKIXOIUEA CAMERATA OF NOHTII AMERICA.

wliicli are lanoli wider than tlie first, siipporling 2x2 palmnrs. Tlie pos- terior ray iia.s three disticiials anil no palnmrsi. Avni facets .slightly concave, tlirected obliquely upward ; the anibulacral openings small and equidistant, except the one between tlie posterior rays, whicli is not only wider but a little indented. Structure of arms unknown. Regular interbrachials one or two, the first large, the second, if present, quite small ; roofed by the palniars, except at the anterior side by the upper distichals. The anal plat? supports two rows of three plates, of which tiie middle ones are larger than those at the sides; the upper one rising to the height of the first pahnars, and arched over only by the arm bearing plates. Disk rising but little above the upper margin of the cup; composed of highly convex, somewhat tumid plates. The orals and radial dome plates — the latter of a first, .second, and third order — larger tlian the interandjulacral plates. Anal tube almost central, rather large at the base.

Hiirizon and Ldculitij. — Lower part of the Lower Burlington limestone; Louisiana, Mo.

Tjiiic in tlie collection of Prof. Rowley, at Fort Smith, Ark.

licmarJi'ii. — This species departs from the typical JJatucriiiiis in having but eighteen arms, and in the position of the respiratory pores, which are placed so closely to the andndacral openings as to appear always contluent with them in the specimens. It approaches Dizi/gocrinus in its general form and the small size of tlie base.

EatocriDus rotadentatus Kowi.kv ami iIauk. rhilr XL VI. Fill. 7.

IStH, RnwLKY iiiul IIakk; Kiins;is City Scicut., \\. Wi. V\\\U- 2, I'igs, 17 iiml 18.

Calyx wider than high, wheel-shaped, the base surrounded by a small rim. Dorsal cup a little constricted above the basal.s, then curving rapidly outward ti) the arm bases. Surface of plates smooth, slightly convex.

Basals large, erect, rounded at the lower end. and forming a profound concavity, which is completely filled by the upper stem joints ; the suture lines deeply grooved. Radials nearly twice as wide as long, about half the size of the basals, but as large as both costals together ; the latter quad- rangular and pentangular, respectively. Distichals two, short, the second larger than the first and axillary, except in the anterior ray, which has three disticiials and no palmars. The other rays have four arms each, and the axil-

•^'

BATOCRIN'm^T:.

37.J

lary distielml supports 2 X t pnlmars. The arm-bcai'iiig plates are very prominent, being separated by tleep notelies, whieh give to tiie rim, as seen in a dorsal or ventral aspect, a strongly dentate outline. Ann openings almost equidistant, directed upward. Arms eighteen, their structure not known. Interbrachials three ; the first largo, a little wider than long, the two upper ones small. Anal plate somewliiit narrower than the radials, fol- lowed by three plates, of whieh the middle one is considerably the largest, and these apparently by three smaller ones. Disk nearly as high as the dorsal cup, the sides but very slightly convex ; composed of moderately large, conical plates, among which the orals arc readily recognized by their larger size. Anal tube almost central and of moderate size.

IforirMn and Localif//. — Base of the Lower Burlington limestone ; Louisiana, Mo.

I}j2>cii in the collection of Prof Rowley.

licmarlcs. — We regard this species as representing a transition toward Ldhocn'nus and Erctnuicriniis, and we should not be surprised if it had paddle- shaped arms. It resembles in general form Luhocfbius ceqmhmclmtus, espe- cially the larger specimens, in which the arms show a tendency to grouping into pairs ; but the interbrachials are arched by the palmars — or distichals at the anterior side — and consist of but three plates. The species should also bo compared with Erctmocrintis clio Ilall.

f

i

•n

BatoorinuB turbinatus (Hall). Plate XXVII. Fhjs. oa, b, c.

1S5S, .■Ic/liioiviiiu.i liii-hiiKilim — Il.ai, ; Ocol. Rep. Town, Vol. T., Tm-t II., p. 5><7, Tliitc 11, Fig. 1. lS7't. liiiliirriiiiis lurhiiiiilw — Mkkk anil WiiimiKN ; (icul. Hop. Illinois, Vol. V., ji. 307. 1881. lidlofrimis liirbiiiiilii.i — W. (ind Si'.; licvisiou I'lilirorr., I'lirt II., p. IfiS.

S.vn. lUheniiiis Ulim Millku and Giulkv, IbOt; Cifol Suiv. Illinois, Bull. 3, p. 21, I'hitc 5, Fitrs 10, 11, 12.

Calyx to the base of the anal tube generally as wide as high ; the dorsal cup one third higher than the ventral di.'<k. Sides but very little concave, straight from the bottom of the basiils to the plates supporting the free arms ; the latter plates projecting. Plates throughout the dors.al cup almost flat, their surfaces smooth ; the suture lines indistinctly grooved.

Basal cup somewhat obconical, sometimes slightly thickened ; lower face concave and projecting over the column. Radials large, once and a h.alf as wide as long, the upper face distinctly concave. First costals transversely

I

w

•*

376

TIIK CKIXOIOEA CAMICIUTA OF XOHTII AMEUICA.

linear, siaaller than the secoml, quadrangular with convex upper and lower fixces ; tiie .«ueond pentangular, very little wider and longer than the first. Dis- tichals two ; the upper one wider than the costal axillary ; followed by two palniars in two series except in the division lacing the anal side, in which there is but one palmar which is axillary and gives oil two post-palinars. At four sides the pahnars'meet with their fellows of adjoining rays, but at the anal side only the post-pahnars. Arm openings equidistant, directed liorizontally. Anns twenty-two, short, rounded on the back ; composed of two series of moderately long joints, distinctly interlocking. Interradials from one to three ; the first very large, slightly elongate ; the upper ones, if present, quite small. Anal plate longer than the radials, supporting three and two plates. Ventral disk low hemispherical, the plates convex. The orals and radial dome plates, which arc more or le.ss tumid, are separated by numerous small supplementary pieces. Anal tube long, subcentral, con- structed of convex pieces.

llirhon and Locality. — Same as last.

Tiji)e in the (Worthen) Illinois State collection, Springfield.

Batoorinus turbinatus, vnr. elegans Hall. riatc XXVI I. F/<jK Gil, b.

1858. Aflhiorriiiiix liirbiiiiiliis, vnr. ehyuns — Hall; Gcol. Rep. Iowa, Vol. I., Tart II , p. 5S8, Plate 11 ,

FiK'. 5. 1S81. liidwriiim turbiiiatm, var. tl'giim — W, mill Sp. ; Hcvibioii I'alitocr., Pai't II., p. 108.

More elongate than the typical form ; the dorsal cup nearly twice as high as the ventral disk ; sides convex from the top of the basals to the arm facets. Basal disk short, distinctly lobed and spreading outward. Eadials, costals, distichals, and palmars arranged as in the typical form, but there are quite frequently twenty arms (four to each my) in place of twenty-two; and the plates forming the arm bases are less projecting.

Ihtrhon and LociiHt//. — Same as last.

Type in the (Worthen) Illinois State collection.

Batocrinus Macbridei W. and Sp. Plate XXX. Figs. 1, 2, 3.

18S7. IV. niul Sp. ; Gool. Kep. Illinois, Vol. VIII., p. 172, Plate 15, Fig. i, and Plate 17, Figs. 11

and 12. 1890. S. A. Heller j North Amer. Geol. and Palicont., p. 228, F.'g. 253.

iliVn

uatocrixid.t;.

877

1

The smallest known species of Batocrinus. Height of crown not excell- ing 3 cm. Calyx nboiit as wide as high, the arm bases projecting. Dorsal cup obconical ; sides straight from the bottom to the top of tiie distichals, thence curving more abruptly outward ; base broadly truncate. Plates slightly convex, without ornamentation : suture lini's depressed. Color of specimen.s lighter than that of Iihodociiiius lurhyi and DicJiocrmis inormtus from the same locality.

Basals short, forming a broad hexagonal disk, which is but very little excavated at the bottom. Ifadials considerably wider than long ; their upper faces concave. Costals small, quadrangular and pentangular ; the first con- vex below, more tlian twice ns wide as long ; the second not longer than the first but wider. Distichals 2X10; followed by f.vo rows of cuneate palmars, which support the free arms. Arms twenty, comparatively heavy, rounded on the back, :he tips slightly incurved and somewhat flattened. Inter- brachials three, sometimes with a small one on top ; the first extending to the full length of the first distichals, those of the second range arched over by the palmars, except at the posterior side where a narrow piece intervenes between them. The anal plate is followec! by three rather largo pieces, and these by two and one. The ventral ;hsk is a little lower than the dorsal cup, highly convex, and slightly depre-s-^ed at the interradial and interdistichal spaces ; the ambulacra elevated, and covered by several nodose plates of a first and second order. The interambulacral spaces are paved by numerous very small, convex pieces. Orals comparatively small. Anal tube slender, shorter than usual in this genus, extending but little above the tips of the arms. Column short, the nodal joints in the upper part large, rounded at their edges ; the intervening joints comparatively short and narrow, contrasting strongly with the nodal ones. Toward the lower end the joints are more luiiform. The column has been observed by us to its full length in several specimens, in none of which it measures more than six inches. It generally tapers to its distid end, where it termi- nates in a sharp point. Tiie lower part, to about one third of its whole length, bears short lateral cirri, which are arranged singly — not in whorls.

Ifvrizun and Loeitlttij. — Kinderhook group; Le Grand, Marshall Co., Iowa.

Types in the collection of Wachsniuth and Spi'inger.

48

M

I . ;

h

m

n_4-JU!HgJ

mwrnKi^*

378

THE CKINOIDEA CAMEKATA OF NORTH AMERICA.

BatOCrinus POOUIVUU Milt.ek and GuRLEv. Flate XXX. Fi</. 6.

1890. Descr. New S|)cc. anil Gum. of Kcliiiioil., p. 34, I'liilc 0, Figs. 0, 7.

Somewhat laryer thiiu tlie prccuiliiig spceiu.s. Dorsal cup bulging out- ward, spreading but little above tlio costals; the base not projecting; platen nearly flat; suture lines obscurely grooved.

Basals short, forming a rounded shallow cup, of which the upper margin is deeply excavated for the reception of the radial.s. Radials once and a half as wide as long, the suture lines toward the costals concave. Co.stals largo for the genus ; the first generally larger than the second. Distichals and palmars two, as large as the co.stals. Arm openings at right angles to the axis of the calyx. Anns twenty, arranged at equal distances ; short, incurving, the tips .slightly flattened. Interbrachials three to four, those of the second row comparatively large. Anal plate followed by three or four plates, and these by three others. Palmars in lateral contact apparently at all sides. Ventral disk .shorter than the dorsal cup, depressed convex ; com- posed of tumid plates. Anal tube long and heavy. Of the column only the upper part is known, which is similar to that in the preceding species.

Iloruon and Loccditi/. — Same as last.

T//pe in the collection of W. L. E. Giu-ley.

Ecmarks. — This form is clo.sely allied to our Batocrinus Muchridci, from which it differs in the more globular form of the calyx, in the more flattened and less spreading ventral disk, and in the greater length of the ventral tube.

Batocrinus pistillus (M. ami w.). Plate XXXI. Flijs. 4(1, b.

1SG5. Aflinorriiius pistillus — 1Ii;kk nnil WiiuTliFN ; rrnrped. Aonil. Nnl. Sci. Pliila., ]i. l.')2.

1S03. A,-linuerinus {ll(ilocriiiiis) pislillKs — Mkkk niul Woktiien; Gcol. Rep. Illinois, Vol. III., p. ili,

riale 1(>, Fii-s. ic, h. 18S1. Balommis pisdlliis— V! . .ami Sr. ; novisinn Pnlfpocr., Pari II., p. 107.

Calyx subpyriform ; the sides of the dorsal cup rising nearly vertically from the base to the summit of the radials, then expanding at first gradually to the distichals, and thence rapidly so as to place the upper palmars and post-palmars in a horizontal position. Plates highly convex ; especially the radials, the anal plate, and the first interbrachial pieces, which are trans- versely nodose.

BATOCRINID^E.

379

Basal cup trilobate, more than twice as wide as long, flat at tlio bottom, a little contraeted at the upper end. liadials more tiian four times as large as the costals, a little wider than long. Costals two, all of nearly ecjual size, but the first quadrangular, the second pentangular; wider than long. Pal- mars in two ranges ; the upper supporting the free arms, except those next to tiie anal side, which are axillary and sustain two postpalniars ; there being five aruM to each posterior ray, and twenty-two to the species. The anal plate is Ibllowed by two rows of three plates each, above which the post-pahnars meet in lateral contact. At the other interradii the first inter, brachials, which are almost as largo as the radials, are fijllowed by one or two small pieces arched over by the palmars. Arm openings directed horizon- tally, arranged at equal distances around the calyx, with a .slight depression at the posterior side. Arm structure not known. Ventral disk hemispherical, a little shorter than the dorsal cup ; composed of rather large, tuberculous plates of nearly the same size. Anal tube almost central, wide at the base ; its length not known.

Horizon and Locality. — Upper Burlington limestone; Burlington, Iowa. (A rare species.)

T//pe in the Museum of Comparative Zoology.

Batocrinus tuberculatus W. ami Si>. (nov. spec).

Phttc XXVIII. Figs. 10a, h.

A very graceful .species, rather below medium size. Calyx liigher than wide, gradually expanding from the basals to the top of the distichals, and thence more rapidly to the arm bases. Tlates of the dorsal cup tuberculous, with well defined .sharp nodes in the centre, those of the brachials forming a sort of interrupted obscure ridge.

Basal cup distinctly trilobate, deeply depressed at the interbasal sutures, flanging outward at the lower end, and depressed at the bottom. Radials about as wide as long, with a large transverse node. Costals small, both together very little more than one third the size of the radials ; the first smaller than the second, quadrangular ; the upper pentangular. Distichals two, followed by three palmars, which support the free arms. Arm bases directed horizontally, forming an uninterrupted line around the calyx. Arms twenty, equidistant, short, rather delicate, flattening at their upper ends, and curving inward; their lateral margins indented, and their backs lined by two

MWI

380

THE CKINOIDKA CA.MKRATA OF NORTH AMKRICA.

rows ofobuciire nodes, Interbracliiiil plates throe, con.si.sting of a large tiiiuid plate, followed by two sniiill, nliglitly convex pieces, above which the three rows of palmars meet those from adjoining rays, except at the posterior side, where oidy the plates of the npper row are in contact. Anal plate longer than the radials ; followed by three and three plates. Ventral disk de- pressed, greatly inflated above the arm bases; composed almost exclusively of the orals and radial dome plates, which are nodose. Anal tube compara- tively slender at the bottom, formed of convex, elongate pieces ; its length not known.

llurizon and Locidity. — Lower Burlington limestone ; Burlington, Iowa.

Tiipcs in the collection of Wachsmuth and Springer.

llemarks. — This species in the construction of the calyx is closely allied to Balocrimis pislilhis, and in the arm structure resembles some species of Erchnocrims.

Batocrinus clypeatus (Ham).

riate XXVII. Figs. 8a-c.

ISnO. Artinormiiif rf'/prn/iis — Mw.!, ; Suppl. Gool. Ui'p. lowu, p. 12, I'l.ilc 3, Fig. 12.

l^^)7. Ai-liiKifriniis (Ihilorr.) r/y/mi/iis — ilKtK niul 'WoUTiiKX ; (iciil. Kup. Illinois, Vol. II., p. 150.

1831. lliilocriiiiK eli/imitiis— \S . iiml Si-. ; Upvisioii ralii'ocr., Tart II., \\ 100.

Si'ii. Aclbiorriiius pii)iill,itiis — Hall; Suppl. Geol. lU'p. lowii, \i. 21), I'liologr. plates (1S72), Plate

3^, l'if,'s. 10 ami 11. Syii. Ilalocrinim papilln/ii^ — Mekk mid Wohtmen ; Geol. Hop. Illinois, Vol. V., p. 307. Syn. Ai'fi/wrri/Hi-^ i/iorin:ftis — II.\LL; Suppl. Gi'ol. I{('p. Iowa, jv 21. Sj-n. Jiii/orriniis iiioniii/us — Meek ami Wobtiikn; Geol. Hep. lllimiis, Vol. V., p. 307; and

AVliilficld, Mem. Auut Mus. Nat. Hist., 1S93, Vol. I., p. 15, I'late 2, Fi-s. 1-3. Syn. Bdlorrinim compnri/i) — S. A. Mn.LKii, 1SU2; Adv. Sheets iMli Hep. ticol. Surv. Iiid., p. 32,

riatc 5, Fiss. is to 20. Syn. lliilorriiiiis dxiirulilis Millek and GuKLEY, 1S91 ; Geol. Surv. Illinois, li\ill. 3, I'late 5, Fiirs. 4, 5, 6.

A very variable species. Calyx a little wider than long ; the dorsal cup higher than the ventral di.sk, convex at the ba.se, the sides conctive. Plates from almost flat to moderately convex.

Basals very small, in some cases invisible in a side view. Radials more prominent than any of the other plates, their median portions more or less tumid; they are wider than long and concave at the upper face. Costals quadrangidar and pent.angular. both together smaller than the radials ; the first smaller than the second. Distichal.ri two, as large as the costals, each one supporting 2X2 palmars, which are in contact laterally and support the free arms. Arm openings twenty, arranged at almost equal distances, the inter- spaces slightly gi'ooved. Arms very short, compo.sed of two series of short

It

HATOCRINIDiE.

381

l

trniisverse pieces with serrated lateral margins ; the tips infoklinjr. Tiie anal plate is a little longer than tlio radials, and followed by three and two plates. The regular sides have two or three interhrachials, of which the first is largo. Ventral disk low hemispherical, the plates more convex thim those of the dorsal cup, and almost of uniform size. Anal tube extremely long, attaining in one of our specimens a length of five inches, which is nearly four inches beyond the tips of the arms; it is stout at the base, hut very thin at the upper end. Column of less than medium size; the nodal joints a little wider than the others; near the calyx they are short and rounded at •.lie edges, but they gradually grow longer and cylindrical ; at four inches from the calyx all the joints are of equal size and of nearly the same height.

Jlorkon (iiul Lociillfi/. — Same as last.

T//2)es in the (Worthen) Illinois State collection.

Remarh. — We have found it utterly impossible to separate Hall's " Adinocrbim " jxipillatus and " Actinocrliius " inornatiis from this species, although we took the utmost pains to do so, and had the types for com- parison. We have before us over one hundred specimens, which agree in all essential points, but dififer more or less in the convexity of the plates and the form of the calyx. Tiie plates in some of them are entirely smooth, in others distinctly convex, and while in some the cal^'x is much wider than high, width and height are almost alike in others. Miller's B. comjxtrilis is identical with the typical form.

f

Batociinus grandis (T.von). Plate XXVII. Figs, la, h, and 2cu b.

1859. AeHnomnm graii'lin — Lvnx ; Amcr. .Tourii. Sol, Vol. XXVIII., p. 240.

1S33. Ilatocrinm griiiiilis — W. iiuil Si'.; Ucvisiou I'lilicocr. I'lirt IH., p. 113.

Syn. Adiiiorriiiiis Wuchiiiidhi — White, 18S0; 12th Aim. Ki^ji. Terr. Iiy ITnydcn (Aiillior's Kilit., p. l(k'). I'liile ■*". l''!!?"- 1". *. ■'""1 £■''«!■ Ht- l"ili"»i» for IS'O-SO, p. Ii2, I'liii.' 7> I'ii;. fi {""t Afliiiorriiiiis Wdchxiiiiitlii White, '\SC>-1 = Ac/inoeriiiiis sci/ii/ui ; nor Jiii/ocriiiii.i ll'in-hxinullii, lievisidii I'lilicncr., Part IT., p. IBS).

Larger than the preceding species, and proportionally higher. Dorsal cup gradually expanding from the top of the basals to the top of the dis- tichals, thence abruptly to the bases of the free arms. Plates convex. Radials and distichals covered by transverse nodes, the interbrachial pl.;tes by round ones, which grow shorter as they approach the arm regions.

Base broad, decidedly lobed ; the plates thickened at the lower end, and slightly projecting laterally ; the interbasal sutures deeply grooved. Radials

1 1 •

; VI

Jk

\\

I »

882

Till-; C'UIXOIDKA CAMKUATA OK NOUTH AMKUICA,

wiiU'i' tliiiii long, InrgiT timii botli CDstals togotlier. Costalu nearly equal in size; lliu (iist quiulniiigular, wider tlmn long; tlic second lieptagoniil, a little wider tlian the first. Distielmls two, transversely arranged; those of the three anterior rays followed Iiy four to five short pahnars, whieh ,sn|)|iort the free arms. The pahnars of tiie two lower rows are as large as the distiehals and resL'nihle fheni in form, the upper ones curved like arm plates and smaller. The two posterior rays have five to si.v arms, — exceptionally seven, — ihe other rays invariably four. In the two former, either both outer palmars of the seeond row are axillary, or only the one faeing the anal side. Arms long, but comparatively thin ; rounded at the proximal end, slightly llattened at the distal one, and composed of two scries of transverse pieces united by a zigzag snture, each plate covered with two delicate nodes arranged into longitudinal rows. . Interbrachial plates : 1,2,1. Anal piece narrower and longer than the radials; followed by three or four plates, and these by four to (Ive others of irregular arrangement. Ventral disk hemi- spheric; tiie jilates tuberculous and of similar size, except those at the pos- terior >iile which are .xomewliat smaller. Anal tube very long and stout, extending far above the tips of the arms; the plates rather large, pentagonal or irregularly hexagonal, and each one covered with a sharp central node. Column large, the nodal joints angular at their edges, and considerably wider than the intervening ones, which, however, increase in width as they pass downwards.

Horizon and LocaVdy. — Keokuk group ; Crawfordsville, Ind.

Ti/pcs in the Lyon collection.

Remarks. — This species is labeled in several collections Erctinncrhuis mngnificns. which is a totally difTerent species. AYhite's Adinocrinus Wachs- vuit/il is identical with this species.

BatoorinuB mundulus (TIali,). Phte XXX. Figs. 4a, h, and 5.

1850. Arfinofriiiiif mniir/ii/iif — TlM.t. i Siipjil. ficnl. 'Rc|i. Town, p. .30.

ISSl. liiilDcriimx miiinliihis — AV. and Sp. ; Hcvisirm I'iilimpr., Part II., p. 107.

Syii. Ai'Hiiocriiiiin .liiiiili^ — ll\i.i., T^.'O; Siip|)l. fii'iil. Rep. Town, p, 10.

Syn. Ild/oiTiiiiis simil'm — M. nnd W. j Gcnl. l?c'p. llliiuiis, Vol. V., p. '^(^%.

A small species. Calyx higher than wide ; the dor.sal cup gradually spreading; its base broadly truncate; the sides straight or a little convex. Radials and brachials marked by transversely arranged, ob.scure angular

IlATOCRINIDvK.

883

ritlgos ; the iniirgins of the plates beveled, so an to make the isiitiUL' linoH quite distinct.

Udsala "liort, thickened around the lower niiirginM and I'orniiui,' ii hexa- gon; the ver faco exeavated. Radials widur tiian long. Fir,>t rostaln quadrangidar, their length ecjual to hall' their width; the second jn'Mtan- guhir, often smaller than the iir.it. Distiehals ii X 2 ; tliu.-ie o! tlie ui)in'r row wider and axillary, supporting 2 X li palniars. Arms L'ighteL'u to twenty. Sometimes the anterior ray has hut two arms, and in place of pahuars an additional row of distichals. Arm openings e(|uidistant or nearly .so. Arms of medium length, cylindrieal, deeidedly tapering at their tip.s. Anal plate a little narrower but longer than the radials, sustaining three and three plates. The first plate of the regular sides quite large, followed hy two or three smaller ones, which are arched hy the palmars. Ventral di-U high, conical; composed of irregular, convex pieces, whicli pass gradually into the anal tube. The latter is central, stout at the base, but not very long. Column tapering downward, the nodal joints projecting.

Jl/n'zon and LoaiJilij. — Keokuk group ; Keokuk, Iowa and Nauvoo, Ills.

TijpK in the Illinois State collection at Springfield.

liemarkt. — Ac/iiiocrinus siiiillis Hall is identical with this species, except that it has only two arms in the anterior ray.

'I

IH I

Batocrinus cantonensis ^r. and Ci.

Plate XXVII. Figs. 7«, h. 1S90. Miller nnil GuiiLEy; Jourii. Cinciii. S«p. N':it. Hist., Vol. XIH. (.Iiiiic), Vhte n, Tii;. !),

A rather small species. Calyx about one third higher tlian wide ; the dorsal cup higher than the ventral disk, broadly truncate at the bottom, and straight or slightly convex at the sides. Radials and brachials extended into well defined transverse angular nodes; the interradial plates eveidy convex ; the plates of the tegmcn and anal tube distinctly nodose.

Base broad but short, the lower edge .sharply angular and indented at the suture ; the bottom flat, except the middle part, which is slightly exca- vated. Radials considerably wider than long, their ridges directed obliquely downward. First costals very short, linear. Second costals pentangular, longer and wider than the first. Distichals 2X2; the npper ones axillary, giving off a palmar from each side, ''^b j anterior ray generally has no pal- mars, and in place of them an additional distichal. The palmars are in

u

384

Tlir, CKINOIDK.V CAMEUATA OK .NOKTII AMKIMC'A.

cuiitiict with (iiie iiiiotliur uiid with tliu tliicil disticimls ui' tliu iintoiioi' ray. Arm bases not projet'tiny ; tlio iiriii opuniiigM ccjuidi.Htant. Anns eighlfi'ii, of niudiuni lengtli, rather utoiit, and griuUudly tapering; coniponod of nitlicr long joints, wliic'h on thu l)iick aro niarivod l)_y ii whort ronndud node. I'in- nidos long. Veiitiid disjt constructed of irregularly arranged nodose [dates; and similar i)late< form the walls of the anal tube, which is comparatively strong and cxtend.s beyond the tips of the arms. Column tapering down- ward; the nodal joint.s with creiudiited edges, and rather long; the inter- nodal joints (juite narrow.

7/'/ /■•,•// itiiil Liini/i/ij. — Keokuk group; Canton, Ind.

TijjM in the collection of W. F. E. Gurley.

liiiimrks — Miller and Gurley describe this species as having four arms in the anterior ray. This must be exceptional, for seven of our specimens whow distinctly but two arms in that ray, and eighteen to the specimen.

Batocrinus laura (irAi.i.). Plate XXIX. Fi<jH. on, b, r. L

fftl. Ai-lhmi-riiiii^ tniira — n\I.I.', TVcliin. llrsor. Ni'W Criiiimls, ;i. I'l. 1S31. Jlii/o''riiiiia lauru — W. luiil Si'.; Id'visinii I'liln'iicr., I'art it, p. 107.

lS'j;t. /;,//.,-,■//»«,» /,(««(— WiiiTKlKI.L); .\lc)ii. .\iiuT. Mil-. N;a. Ili'tl., ISOIl, Vol. T., p. 17, rialol, Fi,!,'s, 15. 10. Svii. Ihilui-riiiiiH fri/jiliKs .Mii.i.tK iiiul (iriiLEV, 1^'Jl; Gc'iil. Surv. llIiiKiis, Hull. ;j, p. iX riiili' 5, Fi-s 7, H, 0.

Caly.x gen-rally higher than wide, biturbinato. Dor.sal cup gradually and uniformly exi)anding to the arm bases, its sides straigbt or slightly ton- cave ; the plates Hat and smooth. I'asals not projecting laterally, forming a short conical cup, rounded at ihe l(j',ver edge. Radials a little wider than long, their upper faces concave. First costals less than half the size of the radials, (juadrangular, once and a half as wide as long, the lower face convex. The second smaller than the first, pentangular. Distichals 2x2, larger than the costals; the second larger than the first and twice ns wide as long. The upper su[iports 2x2 palmars, of which the second is deeply excavated, and forms a horse-shoe-shaped facet for the reception of the arms. Arm openings large, directed obliquely upwards; equidistant. Arms rather stout, of moder- ate length, rounded on the b.ack. Interbrachials : 1, 2, and 1. The anal plate is followed by 3, 3, and 1 plate, arched by the palmars. Ventral disk lower than the dorsal cup, more or less conical; plates almost flat, except the posterior oral, which is somewhat convex. Anal tube central, of

l>^

1^

•^ATOf RlXin T..

885

nietliiim size, extending hp^'opml, (lio tliwi '^ no nnn«, Sfrueluic of colmnn unknown.

Jforhvn (111(1 Locdlltij. — tJiit-fT BurliHjrton limoMone ; Burlington. Town.

BatoorinuB laura, var. sinuosus (Ham).

ISflO. Arlinnrriiiuf jmkowj— IIai.I,; Siipiil. (icul. Uc|i, \m\i\, \\. -27. l'linlii(.'r. jiliilc (l<i*i) 3 ,<, Figs.

H mill <). ISr.'l. lififijfn'niit tliiiinfin— Mkkk nnd U'liiiTilKS', fi.'iil. Itc|i Illiimii, Vul. V., |). 'lOS. ISSl. Jld/iirriiiui siniiiifiif — W.:ml Si',; ItciMciii I'lilii-ici'., I'lirl II., |i. IfiS.

Thin fornj is no closely allied to Bd/nrriiins tiiifn( tlmt wo rojjnri) it a variety of tliat .species. It is said to dilTer in liavinj; a more pointed liase. a deeper groove between tlio two |)osteri<)i' rays, and tliat tlie intevln'acliials of tlio anal side pa.ss into tlie interainhnlarral idntcs. tlicreliy approncliing Lohorriiiiis. Tlie anal tube is moderately largo and almost central.

Ilurizon and Lncalili/. — Same ns last.

Type in the Illinois State collection at Springfield.

ERETM00RINU8 T.vr.v .in,] Cas.s. lil'l. TiVoN nnil CissEriY; .\iiirr. ,T;!uni Sri. aw\ .\rls, V..1, XXVIH, (scr, 3), p, 2H.

IStiU, SlIUMAIin (llll)l{PUUS of -/(•/l/(«.'/-|««.) ; ('alillcil,'!!!' I'lllll'dZ. l''cl^^^. I'llll I,, p. Ilfill.

ISfi'J, .Mkkk tiiiil U'diiTIIK.s (»iil)j,'ciiiis iif lliilo<-riii(i-) ; I'ldcri'd. Acad. Nat, Sci, I'liih , p. ,'?.',0.

IS'li. Mkf.k iiiul WdliTIIKN (siil>,'i'iius of nulorriiiiit) ; Ocnl. Urp. Illiiiiiis, Vul. V., p. Hfi8,

1S7S. \V. and Sr, ; I'rcicml. Aciid. Nat. Sci, I'hda., p. iX>.

1S7'J, ZlTTKi, (Mclifjiniw (if .tcliiiiu;-iiiii.<) j llaiidli, drr l'alii'nnt(dii!,'ii', Vcd. I., p. .1*1.

ISSl. W. and Si'.; Itcvisi.iii I'ala'ncr., I'ai'l 11.. p. 1711 (I'rnc ,\™l. Nal. Sri. I'liila , p. :U1).

18S3. W. and Si'. ; U.'visinu I'liln'oor., I'arl 111 , p 111! (I'luc Acad. Xat. Sci, I'liila., p. IW,')).

1890. S. A. MlI.i.KU; N'lirlli Aincr. (;clllll^7 and I'alicmit., p. Hi. Syn. .IrliiioiTiiiiii (ill pari), Ham, ISnOniid ISdl.

Caly.v more or less depressed, broadly truncate at tlic base ; plates (Int or nodose, the surface sometimes granulated, but generally smooth . Basal- short, forming a broad rim, wdiich projects conspicnou.«ly outward. Radial.'^ ns large as or larger than both costals together. Costals two, short, wider than long; the first quadrangular; the second pentangular or except inuidly lioptangular. The higher brachials in contact laterally, and forming a continuous ring around the calyx. Arm facets directed horizontally ; the ambulacral openings arranged in groups; respiratory pores well defined. Arms from twelve to twenty-six. When there arc more than twenty', llio addition is made in the posterior rnys, the other rays having four each. In species with less than twenty arms, the anterior ray has the least nunil)er. Species with sixteen arms always have three in the posterior rays. The arms are paddle-shaped, narrow and rounded in the lower parts, broad and

49

■ I

3S0

Till". CKrN(»n>KA C.VMKUATA OK NuUTM AMKUK'A.

llatlfiii'd iiIkivc ; they nro l)if<criiil, Imii,', im<l iiuMirvint;, — tlicir lips Honio- times (Icscciiiliiig to tlio toii of the ciilyx, — ami ai'u coiniio-'cd ut tlicir Iiii.xch of Nlioi't traiiHVi'i'Mu piocoH, ^vliicli grailiiully iiioruaHu in leiigtli uiul wiillli upward. Iiitoii'adialrt nut nuiiieroUH, (licrc boin^ IVoiii oiio to tlirci' |ilal(<M at lliu rojjniar nidi's, and from four to k'M'U at tlu' anal side includinjf tlic anaN. Ventral ilisk ilistinctl^' a.xymmetrical, xomewliat bulj,'iug aud luj,'lier toward the anterior Hide, rather flattt-ned ponteriorly. Posterior oral eon- HpieuouH, large, and central in position; tho nnul tiibu oxccntrie and ol'leii curviu); oulwiwd. Colinnn roumi ; tin? axial eanal snudl rud peutMn>,ndar,

Dislriliiiliiiii. — lieslrieted to the Iturliuglon limestone aud Keokuk group, and, HO far as known, eonlined to Auu-riea.

Ti/i'C of tho genus : KnlnKinliiim iiiiiijiil/iriiit Lyon and CawH.

Ji'iiii(td.i. — Meek ami Worthen treated KnlnuwruiiiH ns a subgenus of Biifiiirniiin, and added several forms wlii»:h do not lioloug to it. It dilTi'rH from Iliitixrl/iiiK in tho broad, triuicated, aud projecting basals, tho long, paddlo- shaped, and iueurving arms, their arrangement, tho nsynnnotry of the ventral disk, and in tlie e.xeentric position of the uiuil tube, — nil of which are good disliuetivo characterH.

ErottnocrtmiB magniflcua t.vun and Cass. J'Mc A'A'A'T'y/. !)■>/. J.

18:i!) T.ynv mill Cassfiiw; Aiiirr. Jiiiirii. Sii., Vol. XXVllf., y. '2H. ISSl. \V. mill .Sr. j Hivisidii I'liliiMicr, I'mt II., p. liH.

(\iit K:-''luiorri,iiii mii;iiiijieiii (JlKKsTKUTi HiiuiUi. ilir I'liliiunl (AiiflnftP 3), PMo 77. Fig. 11 =

JiiitiifriHm fjriinfli*), S^'ii. KrrliiiiH-riiiiin li/tiiiiiiiH.i S. A. Mli.l.tli; Ailv. Sliocts I7lli (ii'iil. licp. Iiiilimiii, IS'.M, p. .V.t, I'l.-ilii 10, Fi(,-<. ;t mill \.

Caly.x higlier than wide, biturbinate ; the dorsal cup fre(|uontly .sliortcr than the ventral disk ; bro.'uliy truncate at tiie i)aso ; the sides concave, spreading abruptly near tho arm bases. Tho rndials and brachials in well- marked specimens are koel-shapod, with a promiuenco or node in the centre ol' each plate, in others they are simply convex ; the intcrbraehial plates, in most of the siiccimous, are perfectly flat.

Hasc short, extended into a broad rim, wdiicli project.s considerably beyond tho radials ; it has a shallow depression at the bottotn, nnd a some- what deeper one for the reception of tho column, which occupies less than half tho diameter of tho lower face. Radials tnorc than twice as wide as long. First costals quadrangular, about half the size of the radials ; tho

M'

UAKKIUXID.K.

387

H ml |H'iitniif.'iiliir. tlicir Klopiii^ niipiT faOL's jiliiroil at rij(lit imnlff*. Dif-

tii'lmlM l\\(i, tlic iixilliir)' I'oiixiiloriil)!}' wiilcr. I'lilniiii.i tlii'i'(>,Mli(ii'ti<i' tliiiii lln' (1iMti(!liiilN, in ciintiict lnti'mlly, iiinl hd iinini^^i'il tlmt (lie wilicrit im);li' of <iiii' pliito rcxtH witliin llic rclrciitiii;^ ntijflc I'dnin'il liy tl(t> two mljoiiiiiig pii'CL'». Arm o[)t'iiiiigi (liiiKMuil lioriziiiiliilly, aiiiinj,aMl in gi(Mi|)s, (Ik! iiiti'i>*iiiico'< hotwoi'ii tlio I'ayH beinj^ wider than tin' oliicrs. Arms Iwi'iity, uxcoptinniilly twoiity-two, wlion tlii-ro aro (ivo in tlio two poMterior rnyn, Acconlinn to liVon and (.'asuoday, tlic arms aro four incluw lonjr. siilicylindrical to ono tliird tlu'ir lrni;lli, when tlicy llattcn ami cvpiniil upwanls. rcacliinj^ at iniilway ii wiiltli ot' lialf an inch, am! a il('[iih of ono fixtoontli, hut higher up thoir width i-i roducocl to ono half, and thoy end in a ronnih'd odgo. Tiio armx ai'o hiscrial al)i>vo llu! (ir.Mt or hocoikI IVoo pinto 'I'ho plates aro Khort near the calyx, l»nt incroaso in ionglli upward. Inlerradiais two to threo ; tlio first rining to «iio half tho height of the first dintiohals. Tlio anal intorradius has six platen nhovo the anal, nrrnnged in two rows. Vi-ntral ili-k high-coniral, surmounted hy a unuill, almost central anal tuho; the plate.s large and tumid.

Ilni'lxoii mill Lnnilitif, — Keokuk group; Clear Creek, Hardin Co., Ky.; New HosH, Montgomery Co., Ind. ; Pilot Knoh, near Louisville, Ky. ; and White's (,'rook >>|,iii)gs, near Naslivillo, Tonn.

Tijiic in ili'o collection of tho late S. A. Cassoday.

ErotmocrinuB ramulosuB (HAi.t.). /'/(//(' XXXVII,, F'kju. 4<i> '') mill '^ "> ^> ". '/•

1S.')S. .I'lhinfriiiiit ruiiiuln'iif — 1! M,I, ; (Irnl. lli'p. IdWn, Viil I., I''irl II., p 111,'), Vlnlo 15, l"\g, 7. 1^81. llri'tniarriiiti* tiimiil't^ft^ - \V. mill .Si*. ; Itcvisioii I'.'ilii'ncr., l*Mrt II., p. I71i.

Nut Kniuiiifriiiiii nii/iiilH'iit W. ami Sf. j 1S73, Tructr;!. Aeail. Nat. Sci. I'liila., p. •^.'tl']=: Kifhiiocrijiin rfiiti/jnii'/iiiifit-^t viir. rxjui/isus.

The largest species of thi.i genus. Tn its general aspect closely rc.«cni- Wing /v. iinii/iiifiriis, hut more rugose; the ridges and nodes more prominent ; the liaso narrower; the ventral disk larger, and hemispherical instead of conical ; tho anal tuho mui'li smaller, being reduced to tho mininuuu. Dorsal cup short, rajjidly spreading, truncate at the base. Plates elevated and covered with sharp central tubercles; those upon the radials and brachials coullucnt, forming undulating angular ridges, which branch upon the axillaries and pass into the arms, producing deep depressions between the various divisions of tho raya. The radials and brachials have two addi-

h til

i '

388

THE CIMNOIDKA C.UIKIJATA OK NOinil AMKKK'A.

tiuniil luidi's, one to each side, of wliicli tlioso upon the nuliiils are coiuiocteil witli the centiiil node by ii fnmsverse ridge.

UmsuI ring slightly innjeeiing laterally, more or less notclied at tiie sutures, and moderately excavated at the bottom. Kadial.s twice as wide as long; tiieir transverse ridges pointing downward, sometimes reaching as low as the truncated lower end of the basals. First costals one third smaller than the radials; (|i'adrangular. Second eostals generally a little wider tiian the first, and of about the same length. Distichals two, shorter than the costals. Palmars short, in rows of three, except in the posteiior rays, in .vhicli the subdivision next to the anal interradius, and in large si)ecimens freciuenti}- also that next to the antero-lateral rays, has two palmars followed i)y three post-palmars. Anns twenty to twenty-four; they are at the proximal end narrow and subcylindrioal, biserial from the first free plate, and ('onipt)sed of moderatidy long pieces. The arms have not been found in (losition; there are found, however, along with the calyces, deliu'hed pieces of Erctnwcriiiu^ arms, which probabI\' belong to this species. They are more robust than those of the preceding species, not as wide, and their increase in width is more gradual; their cros.s-sectioii is .semi-oval, the dorsal lace flat and covered with four rows of nodes, of which two are close to the suture Hue, and one to each outer border. Interbracliials three; the first large, reaching to nearly the full height of the first distichals; the two olluMs smaller and roofed by the palmars. The anal plate is followed by tlirre large plates, and these by three smaller ones, which are arched by the post-palmars. Ventral disk bulging, lai'ger than the dorsal cup; the olates large, of abnost uniform si/.e, and tumid. Amis oxcentric, very sj.iall, some times scarcely projecting over the general surface. Column unknown.

ILn-lviin (111(1 Ldcali///. — Keokidi group; Keokuk and Augusta, Iowa; Nauvoo, Ills., and White's Creek Springs, near Nashville, Tenn.

2}//ic in the (Worthen) Illinois State collection.

Eretmocrinus remibrachiatus (U.u.i.).

riiite XXX vir, fijs. ■?«, f>.

ISi'il. Arliiiorriiiiis ri'iiiilir,irlii,(liix — IImi.; I'lvliin. .Niilioi'iif Ninv S|ii'('iis of Crinniils, p. 11.

lSr;>. Itil;.-r. {ICn'/mn-ri/nif) /■.■/,«/i/v/,7//.//«,v— ll.u.I,; Hull. I., N. V. S(i,U- .Mu-i'inii Nal. lli.-l,, I'liitp -t,

Ki^'s, s, n, ISSl. Ei-'-liiHii-riiiiis n'l.iihnirliialua — W. hiul Si'. ; Ucvisidii I'aln'iirr., I'liil II., |i. 17'f.

Calyx bitnrbinate, about as wide as high. Dorsal cup obconical, truncate at the ba.so; the sides slightly concave, spreading uniformly to the top of the

IJATOCKINID.E.

389

^

costiiln, niul thence abruptly to the arm bases, whicli stand out horizontally, forming a projecting rim. The railial plates are somewhat elevated or ronndcd, wliilc the oilier plates oi' the dorsal cup are Hat and without oi na- nientation. Suture lines indistinct.

IJasal cup short, e_)lin(Iricid, wider than the column, and very little con- cave at the bottom. Kadials twice as lar^e as both costals together, their upper laces concave. Costals of about eijual size, transversel\- arranged ; tlie first quadrangular; the second pentangular. Distichals 2x10. resem- bling the costals in Ibrm and size. I'alniars 2X-J0 in the cal^'x ; sul)(iuad- rangular, ami in contact laterally. Arm liicets lunate, directed outward, the respiratory pores small, and placed at the siiles of the ambulacral ()[)enings. Arms four to the ray, e.\ee[)lionally two in the anterior one ; they are very long, broadly paddle-shai)ed, and biserial from the second free plate. To nearly two inches from the caly.\, they are rather thin and cylindrical, whence they grow perfectly Hat, and increase rapidly to the width of eight to nine mm., which is slightly reduced toward the extremities. The Hat portions are thickest along the median line, tiie sides being knife- like witii serrated edges, which turn .slightly outward. At (wo-tliirds ilieir height, the arms generally curve inward until their tips touch the calyx. The proxinud arm [ilates are (piite siiort, but the plates increase (o twice their former length as they widen. I'innules h)ng, composed of long. Hat joints. Int.-rradials, 1. 'J, 1 ; the first very large, reaching the to[) of the distichals. T'he anal plate is followed by three and two plates. \'eutral disk conical, somewhat bulging, often iiigher than the dorsal cup. Tiie plates are highly convex or conical, and of nearly uniform size. Anal tube .slightly e.Ncentric, rather short and slender. Colmmi small.

Iliirhon (tint Liicdilli/. — I'liper Burlington limestone, Murlington, Iowa.

Ti/pcs in the University Museum at Ann Arbor. Mich.

liniiKi-fts. — Professor Hall's description of this species is so indefinite that little can be made out of it, and if it were not for his (igures, which he distriijuted privately among some of his colaborers eleven years later, the species could not be distinguished from several others which occur in tiie same locality. lie give.s the inind>cr of arms as sixteen; stating, however, that there were imperfections in his specimen. Either ITall described one species and iigured another, or the number of arms given is erroneous.

i

390

TIIK CKIXUIUKA CAMKRATA OF NOUTII AMERICA.

Eretmocrinus remibrachiatus, var. expansus ^v. ana Sr. (nov. vav.). Plate XXX VI. Fiij. 1 ; riale XXXVII. Fi(js. la, h, and FlaU XLIV. Fij. 0.

Baloeriiiiin {Errlmocfiniix) reniibruehiiiliia {\n |iMri) — Mkkk ami AVouiiien ; Geol. Kcp. Illinois, Vul. V.,

p. 3711, i'liitL' 10, I'ii,'. 5. Erchiioeriiiiis niMalusiis (in part) — W. nuj Sr. ; 1S7S, rrooccd. Aciul. Xiit. Sci. I'liila., p. 230, nnil ISSl, Itcvisiim I'alii'ocr., I'liit 11., ]). 173.

Svii. ErcliiioiTiiiiis casscJiiyanus Millcii and GuuLtv, IbOi; Illinois Geol. Surv., UuU. 3, ]). 17, I'liUo 3, Fig. 1.

Larger than the typical form; the ventral disk more bulging and com- paratively higher; tiie plates more tumid; the anal tube shorter and more slender ; the costals proportionally larger, the second frequently hexagonal or hcptagonal owing to the comparatively small size of the fir.st interbrachial. The palmars of the two posterior rays in the subdivision next to the anal interradius consist of but one plate, which is axillary and supports two post- palmar.s, thus giving to those rays five arms in place of four. The arms at their widest parts .sometimes reach a width of from 18 to 20 mm. ; they ai'e in the majority of specimens spread out horizontally to one half their lengtii, when they curve abruptly upward and inward, and fold b;;ck in a straight line to the calyx, forming a flat, circular disk, in which the serrated edges of the arms frequently interlock with tlio.se of adjoining arms.

Ilorr.on and Loadttij. — Burlington and Keokuk Transition bed; near Burlington, Iowa, and Henderson Co., Ills.

T(jjics in the collection of Wachsmuth and Springer.

Eretmocrinus granuliferus w. and Sr. (nov. spec). Fhdt XXXIV. F!cp. .5a, h, c.

This species has its closest affinities with E. nmlhruchhdm, from which, as well as from all other species of this genus, it differs in its unique orna- mentation. While in that species the plates are flat and perfectly smooth, they are here slightly convex, and the whole dorsal cup is covered by irregu- lar but distinct granules or small nodes, densely crowding the surface. There are no ridges or stria} either on the radial or interradial plates. Dorsal cup wider than high, rapidly spreading from the top of the basals to the arm regions.

Base broadly truncated, expanding laterally into a broad trilobate rim, flat at the bottom except in the middle, which to one third the width of the

'\H^

"T

BATOCRINIDiE.

891

^m

lower face is slightly excavated for the reception of the column. Radials largo, twice as wide as long. First costals by one half narrower and shorter than the radiala, quadrangular ; the second pentangular, wider than the first. Distichals two ; the upper one axillary, giving oft" from each .side two large palmars, which support the arms. Arms twenty, four to each ra}'; long, incurving and biserial ; at their bases they are somewhat angular on the back, but at an inch from the calyx they gradually llatten and increase in width, reaching at half length their greatest diameter — 8 to 9 nmi. — which they retain a short distance, and become reduced to 5 or C nun. at tho tips. The sides of the arms are knife-like, with dentate edges, the median portions considerably thickest. Tiie arm plates increase in length upward from 1 to 3 nnn. Interradials three, in two rows ; the anal plate is succeeded by three and two pieces. Ventral disk high, conical, passing grad- nally into the ventral tul)e, which is rather long and stout. The plates of the tegmen, including those of the ventral tube, are strongly tuberculous.

Horizon (iihJ Lnculi/i/. — Keokuk group; Indian creek, Montgomery Co., Ind., and Canton, Ind.

7'ujic^ in the collection of Wachsmuth and Springer.

Eretmocrinus minor w. .ami Sr. (nov. spec). r/<i/r XXX VI. Fhi.% 10(1. h.

Calyx subpyriform, higher than wide. Dorsal cup constricted at tho basi- radial sutures, tiicnce ex[)auding moderately with straight sides to the arm bases. Ventral disk scmiovoid, slightly iiitlated at the anterior side, the jios- terior side somewhat depressed. Tiie plates of the dorsal cup perfectly Hat and smooth, those of the tegmen a little convex.

Base broadly truncate, moderately high, slightly expanding downward, tlie lower edges sharply angular, the bottom flat and hexangular. l»adials nearly twice as wide as long, the npper face concave. Costals comparatively large ; the first quadrangular, a little shorter and considerably narrower than the ra<lials, their upper and lower faces convex ; the second wider than tho first and heptangular, the sides abutting against the second row of inter- brachials. Distichals three in the anterior rny, supporting two arms; in tho other rays one division has three distichals, the other Init two, of which tiie upper one is axillary, giving off a palmar from each side. Occasiomilly one or both antero-lateral rays have four arms in place of three. Arm facets

)f'l

302

TIIK ( UINOIDKA CAMKIIATA Ol' NOIiTII AMKUICA.

riitlicr (l.-i'iily coiiciivc, <lii<'(\tc'(1 oiihviiri], Aniliiiliiri'iil opcniiifiM iirniiij^fcil in ^r()ii|)s, tlio NiiaccH l)L't\vc'('ii tliu posterior ray.s widci' tliiiii tliusc IjL'twi'cn tiu; odior riiyH. liesjtinitory porow largo, iirriingiMl in fivu pairs intorradiiil in position. Arni.s tw(dv(; to I'onrteen, incnrvin;,'', cxtrtiinoly licavy for (Ik; sizo of iIk; Hpccios ; llicy an.' Ijiscrial (Voni tiiu H('(;on<l free plato, ronmlcil on tlic hack in tlii! lowi'r portions, hut liat and sjialnlate aliovc, rcacliinjr a widtli of lln'i!0 tiin(!s tlio diameter at the base. In the roumled part, the haol\ of eaeli allcrnnic plM((! in hoth scries is covered hy a small iioije, whicdi doi^s not extend lo th(! Iliittened portions; (lie arms ar(! I<eel-shap('d, heavy ahmj^ the median line, and knife-like at the edj^es. Interhrachials three to four in (lie (our rej.'nlar rays; the first large and \vidt;r tlian high; the upper smaller and anhed hy the arm-hearing hrachials. At the posterior sid(i the anal is lc)llo\veil hy three and two ])ie(u;H. 1'he ventral di>k consists of hut few jilatcs, of which the posterior oral is (he largest; it is slightly convex, central in position, and hends \ipwaril, forming a part of the ventral tuhe ; the other orals and radial donu! jilates are somewhat n.iilose. Anal tube excentrie, larg(! at (ho hnse, and curving to one side.

Jfiirizmi iiikI f/irnlili/. — Upper IJurlington limestone; IJmlington, Towa.

Ti/jiiti in the C(jlleetion of Wachsmuth and Sjniiiger.

Erotmocrinus deprossus w. ,iim1 Si. Oiov. sjn o). /'A//, A'A'A'fV. /Vyv. Jl<,,h.

Near Kriiiiiorriinis riinihrni'liidh's, hut the proportions of the calyx fpiite dilTci'ent : the ventral disk comparatively shorter ami less bulging; the bot- tom of the dorsal cup considerably broader, and (he arm ojienings directed obli(piely upwards in place of hori/ontally. 1"he dorsal cup spreads nioder- atel\' from the top of the hasals to the top of the distichals, thence abru|)tly to the arms ; its height is ecpial (o ono (bird its width nt the arm bases ; the rays are indistinctly lobed. The ])lates var}' fiom almost flat (o distinctly convex ; they are without ornamentation, and the suture linos ait! obscure.

Rase extended outward, forming a broad, projecting rim with a sharj) edg(! at tlie lower border; its lower face; almost flat, and only oiu; (hiid of its width is occupied by the colunni. iJadials com)iarativeIy small, a little wider and somewhat longer (han (he costals; tin; latttn' quadrangular and pen(angiilar. Disdehals two, the npper one axillarv", giving off from each side (wo short i)almars supporting four arms; the anterior ray exceptionally

I

<*■

I

llATOCUIMD.i:.

'M-i

^•\ ^ I

hiis but two arms, iiiid an nilditioiKil (li.sticliiil in plaoo oPiIk; iialiiiars. Ann o|tcning.s alniust equidistant; lln! .spaci^ l)utu(M'n tlio two iio.stcrior iii_)s .■■oino wliat wider and nioro dunply groovt'd than tiiosu hotwudn tliu utliur lay.s ; Htructuro of the arinn ludiUinvn. Inteiitracliials one and two, iiielicd ]>y llie palinar.s. Anal plate higher than the ladials ; it Mipporl.s three; plates, (jf whieh tiio middle one i« the longest, and i« I'oIIowcmI \iy an elongal' |)iece, whicli restH between the palniars. Ventral dink Mhorler than tiie d(jr,-ai enp, depre.sHciI conical ; the plates (.'onvex. Posterior oral central, three or lour times us large us any other plate of the legmen, and strongly nodose. Anal tube excentric and snuill.

llnrh.iin mid /."culil^. — Upper Burlington limestone, JJurlington, Iowa.

T>/i)iii in the collection of Waclismutb and Sj)ring(;r.

Eretmocrinus clio (IImi). J '/air XXXVf. Flijx. 2a, h, and Vlali: XXXVU. Fl:,>i. f)a, h.

ISCi. A''liii'irriiiiif rifj — IIm.i,; I'lcliru. l)i-.or. Ni-w f.'riimiils, p. 1, ainl lio".!!!!! .luurri. Niil. IIi~t , V'/l.

VII., p. iiVi, riiOl.,i,'r. I'liitc; \, V\K. 7 (1-7^, .V. V»ik ,M-itc Hull. \„. I;. ISSl. Ktrtimcriiimclin — W. luiil Hr. ; r.nisiciii l'.ilii"irr., Tail II., |>. \'i.

Consiflerably below mediiun si/e. Caly.x a little higher than wide, grad- ually and unilonnly expanding from the ba.se to the top of the distichals, thence spreailing somewhat more rapidly to the arm bases; \eiitral disk depressed hemis[)herical, aI)out one (iltb shorter than the dor.sd cup. Plates from almost flat to moderately convex ; the first radials and iinal plate a little nod(jsc.

Base higher and narrower tlian usual in this genus; slightly thickened at the lower margins, and prodiiceil into a rim, which is rather dee[)ly e.\- cavated at the bottom, and extends beyond the upper limits of the cobnnn. h'adials proportionally large, almost as long as wide, the lateral faces longer than any of the others. First costals small, (juadrangiilar, a little wider than long. Second costals wider but not longer. Distichals one, large, axillary; supporting two ranges of palmars with four arms, except in the anterior ray which has but two arms supported by two series of three distiedials. Palmars ill contact laterally with one another and with tin; upp(;r distichals of the anterior ray, so .as to form with them a contiinious ring ; the arm-bearing nlates i)rotruding, and rounded on the back. Ambulacral openings facing outward, equidistant, except on the posterior side, where the interspace is larger an<l slightly depressed. Arms long and incurving, slen<ler and roumled

804

TIIK CHIXOIDKA CAMKRATA OF NORIII AMKRICA.

in the lower portioiii', flattened and broader above, increasing gradually to three times their width at tlic base. Tl.ey are composed of a double scries of short pieces, and are provided along their outer sides with small nodes, which in the flattened portions turn into short si)incs. Near the calyx every plate is spine-bearing, but higher up only each second or third. Ee^iiiar interbrachials from two to four, arranged in the usual way, the anal side has three in the first, and two or three in the second row ; the anal plate gen- erally a little smaller t' an the radials. The ventral disk is composed of slightly nodose plates, its anterior side higher than the posterior, the pos- terior oral prominent. Anal tube subccntral and slender. Column rather stout, the nodal joints considerably wider and longer than the intervennig ones, and angular at their edges.

Ifirizoii and Lnonliti/. — Lower Burlington limestone ; Burlington, Iowa.

Tfjpc^ in the University Museum at Ann Arbor, and in the collection of AVachsmuth and Springer.

Eretmocrinus neglectus ^Iekk and WoRTnESf. riule XXXVI. Fiij. 3.

ISCiS. li(ilofrin«> {'Erelmorrimis) iifr/livliis — Mekk and WoiiTiiEN ; rrnc. Acad. Nnl. Sci. riiila., p. 335. lSr3. liiilDrriiiiis (Kn'tmoeriiiiix .') my/t'ClHS — M. ami W. ; Guol. Ucji. Illinois, Vui. V., p. 377, t'lnte 3,

Fiiis. 3,1, Ij. 1S77. Biifoi'fiiiHS iH'i/lfC'ii^ — S. A. XIiUERi Amor. Piiliroz, Fuss., ]i. 72. IS'^1. Errfmocriiiia iii'/ilrvtiis— \\. ami Sr. ; Kovision I'nk'Dcr., I'lirt II., \i. 173. 1S90. Eretiii'jcriiiiis ii,ylfc/ii< — S. A. Milieu; North Aiiier. Gcol. and I'alitont., p. 243.

Of the type of E. clh. Calyx higher than wide ; the dorsal cup inversely campanulate ; the sides expanding gradually from the base to the distichals, thence curving more rapidly to the upper edges of the arm-bearing plates, whicli are slightly grooved but in contact all around ; the plates regularly convex, especially the radials, first interbrachials, and the anal plate.

Radials comparatively large, almost as long as wide. First costals quad- rangular, a little wider than long; the second frequently heptangular, wider than the first but not longer. Distichals one, large, axillary ; supporting two short palmars and four arms in each ray, unless the anterior ray, which is quite often the case, has but two arms, when the largo distichal is followed by two smaller. Arm facets small, facing outward. Respiratory pores almost as large as the ambulacral openings ; they occupy the lower end of narrow, well defined longitudinal grooves, which extend up into the tegmen for quite a distance. Arm structure unknown. Interbrachials generally three, except

»i }

BATOCRINID/E.

395

at the powtorior side, wliere there nre three in the first row, nnd two or three in tlie second. Ventral disk never as iiigh as tiie dorsal cup, and in mmo Bpecimens fully one fourth smaller. Posterior oral and radial dome plates more prominent and larger than the surrounding plates. Anal tube moder- ately large and suhcentral.

Ilorkon and LocuUf>/. — Lower Burlington limestone ; Burlington, Iowa.

Ti/pcs in the Museum of Comparative Zoology.

a rl

ErotmoorinuB calyculoides (Hall). riute XXXIV. Figs, la, h, 2, 3, 4-

I860. Aeliiiomnin ciili/ciiloides — Hall; Supiil. Cleol. Rrji. Town, p. 17 ; Pholngr. rititc 3rr, Figs. 2, 3. \

(N. Y.M-k s'l.ite Bull. Xo. 1.). 1873. Hiilofriiiu.t (Eri'lmoi-riiiim) i-ii/j/i-iilui'k:! — Mkkk irnd 'WoiiTilKN ; fiuiil. lii'p. Illinois, Vol. V., ]i. 3GS. ISSI. Kretiiiofriiiiis cul;/euloiilfs — W. luitl Sr. ; Kcvibioii Fala'ncr., Vint II., p. 172.

Calyx below medium size, depressed subpyriform, as wide as high. Dorsal cup obconical, truncate at the base, the sides gradually expanding from the top of the basals to the height of tiie first palmars, whence it spreads abruptly outward so as to place the arm bases at right angles to the diameter of the calyx. Plates flat, the surface devoid of ornamentation, and the suture lines ob.scure.

Base short, slightly lobed ; the lower end somewhat projecting and form- ing a sharp edge ; the lower face flat, except the median part which is mod- erately excavated for the reception of the column. Radials almost twice as large as both costals together, nearly as long as wide ; the upper face concave. Disfichals 3X2 in the anterior ray, and two arms ; the other rays have 2X2 distichals, followed by two palmars and four arms. Palmars in contact laterally, very short, and curved like free arm plates, having a deep sulcus at each side. Arni facets proportionally largo, lunate, directed outward, and arranged in groups, there being wider interspaces between the rays than between their subdivisions. Arms long, incurving, and biserial from their bases up. To the height of about 3 cm. they are subcylindrical, when they grow flat and widen gradually, reaching at two thirds their height a width of about G to 7 mm., which in the upper portions is reduced again to 3 mm. The arms in the flattened parts, up to their tips, are knife-like, .sharp at both sides, and serrated along the edges ; the plates are short near the calyx, but increase to more than twice their length as the arms flatten out. Interradials three, in two rows, except at the posterior

\v

'■II

\\ 1 ,*]

3110

TIIK ( UINOIIIKA CAMKHATA OK NORTH AMKHICA.

m\v, where tlio aniil pliito is followcil hy tliiTC nnd two piocos. Ventral disk higlior thiiu tliu dorsiil cup, (lixtiiu'lly bulging nt tiic anterior side, nnd lienee shorter at the posterior. The plates flat and smooth, except the posterior oral which is sometimes slightly convex, nnd is strictly central in position. Tlie ventral tube is exoentric, bending obliquely upwards, so as to pass out frequently from between the arms. It is composed of thick, tumid pieces, heavy throughout, stoutest nt midway, and obtusely pointed nt tlio upper end, where there is a small aperture. Colunni small, the upper joint occu- jiying but one third the width of the basal disk.

Jliirhtii ami Luculih/. — Upper Burlington limestone ; Burlington, Iowa, Henderson Co., Ills., and Sedalia, Mo.

Ti/pcK in the (Worthen) Illinois State collection, and in the Museum of Comparative Zoiilogy.

liiinarlcK. — This species is readily distinguished by the bulging and asymmetrical form of the ventral disk, the stout, hiflatcd and curving annl tube, and by the lorm of the arms, which widen more gradually than in any of the preceding species.

Eretmocrinus calyculoides, var. nodosus ^v. and Si>. (no v. var.). riiUc XXXIV. Fi<js. G, 7, 8.

The specimens for which we propose this variety differ from Eretmocrinns calyenlouks in having transverse angular nodes on all radial plates, nnd rounded nodes upon the intcrradial ones. Its general form is somewhat more elongate, less spreading near the arm bases, the radials are propor- tionally smaller, the ventral disk less bulging ; it generally has twenty arms, and these do not attain the same width in the flattened portions. In all other re.spects it agrees with the typical form.

Horizon ami hmtlifi/. — Upper Burlington limestone; Plensant Grove, Iowa.

Types in the collection of Wachsmufh and Springer.

Eretmocrinus matuta (Hall). Plate XX XVI I. Figs. 6a, i, c.

ISfil. Acllmrriiiiif mnliitn — IIai.i. ; Prelim. Boscr. New Spec. Crin., p. 14.

1873. Biitoeriiiiis (Kn/iiiorriinis) naliiln — Mkkk ami WimTiiKN ; Geol. Rep. Illinois, Vol. V., p. SOS.

1831. Eretmoerinm maliila — W. niul Sh. ; llevision Talirocr., Part II., p. 173.

Calyx small, subclavate, longer than wide. Dorsal cup once and n hnlf as high as the ventral disk, expanding but little from the top of the bnsals

n.VTOCIMNID.E.

807

to the foot of tlic imliiiiirs ; tlic liitlcr slij,'!)!)}- projecting outward. Snrfnco of pliitoM I'luvated ; the riuliiils niised into conspiciioiis trnnsverMc nodes; tiie brnchiiiis keel-shiiped, forming angular ridges, wiiieli I)raneh to tlie haxoM of tho arniH ; the firi^t interbraeiiials tumid, the succeeding ones nlniost flat.

Ba.sc moderately high, notched at the sutures ; the lower edges project- ing laterally, and forming a well defined rim ; the bottom rather deeply excavated for the reception of the ecdumn. Kadials very large, three times as wide as the first costals; the latter luuisually small and quadrangular; the second costals somewhat larger and pentangular. Distiehals 2X2, of tlu! size of the costals. Palmars 2X1, in contact laterally, except at the posterior side where they are generally separated by a small interbrachiid piece. Ann openings nearly ef[uidistant, onl}' the space between the two posterior rays being a little the widest and slightly depressed. Ai'ms long, slender, inem-ving, subcylindrieal to one third their length, tlien gradually flattening and expanding to once and a half their lower width; their sides knife-like and serrated along tho edges. Interradial spaces somewhat depressed ; the first interbrachial very large, supporting two small plates in the second row. Anal plate a little higher than the radials. and formed into a, circular node instead of a transverse one ; followed bv three, two, and one plate. Ventral disk hemispherical, somewhat bulging toward ihe sides. Plates large and slightly convex. Between the plates at the periphery there are upon the surface narrow but deep vertical grooves, whieii lead to the respiratory pores. Tho pores are large and arranged in the usual manner. Anal tube excentric, very long, stout, retaining the same width to near its upper end, where it tapers rapidly and is pierced by a minute opening. At about half its length, it curves abruptly at right angles, and pas.sos out laterally between the sides of tho arms. CoUnnn moderately large, com- posed near the calyx alternately of thicker and thinner joints.

Ilorison an'' Locality. — Lower part of the Upper Burlington limestone, Burlington, Iowa.

Typcx in tho University Museum at Ann Arbor, and in tlie Museum of Comparative Zoology.

Remarks. — The peculiar structure of the anal tube, to which we allude in the description, occurs in all our specimens, and has been ob.served also in a fine specimen in the Museum at Cambridge.

Hall, in his Preliminary Descriptions of New Crinoids, p. 14, mentions a form to which he applied the name Act'i'.ourinus matuta, var. attenuata ; but

>» iM

'\&

ki\

31)8

TIIK ( IIINOIDKA CAMKUAIA UK NOIIIII A.MI'.UK'A.

ns no flifiiiv iM given, nml tlio (loscription is insnllicicnt for iik'ntilication, wo lire c(iiii|)iHi'il to iynoro it lor tiu' prcsi-nt. Kvi-u tiiu figure given liy Wliit- flold (Muni. Aiiur. Mus. Nat. Hint. N. Yorlt, Plate 1, Figs. 2;i and 21), inudo from a wculliured fpuciiucii, dues nut aid ua in di.xtingui:4hing thu form.

X

Erotmocrinus cloolia h.m.l. /'/((/(• A'A'A' 17. Fi(j!). 4a, b.

ISni. J,-l!iiii,','iiiH' i'IitUii — lUi.i. J Prelim. IK'sor. of Xi'W Spoc. of Crin., p. 1, «iul nnst. .Tnurn. \:it.

Hist., v.,1. VII., p im.

I*r3. Hdtoeriiiui ^liir/iiim-r.) rhi/ia — Mkkk nml WoliTilKN ; ficcil. lli'p. Illinois, V<il. V., p. M3. ISSl, Ere/immnHt e/ucliii —W'.iwui Hr. ; Itovisicjii raluorr, I'lirt 11., p '.7'i.

A little larger than the preceding Hpcciea. Calyx about ns liigli a.t wide, broadly truncated at the bottom, (ho .sides of the dor.^al cup gently expand- ing to the arm bases. Plates .spinou.s, subspinous or nodose ; the suture lines slightly depressed.

J5a.se short ; the plates distinctly angular nt their upper faces ; the bottom broadly truncate and perfectly Hat, except the central part whic!; is slightly excavated for the reception of the coliunn ; the suture lines deeply grooved. In some specimeii.i there is a longitudinal groove following the median lino of tho ba.sals, which nuikcs the base appear hexapartite, especially if the respective parts, as in .some cases, are extended outward into spines. Radials of moderate size, wider than long, the nppt'r face concave, the surface cov- ered with a transverse spine or node. Costals rather large; the first (puid- rangular, convex at the upper and lower faces; the second a little wider and pentangular. Distichals two or three. The anterior raj', when with but two arms, ha.s three distichals, tho two anterolateral rays — .sometimes also one or both posterior rays — only two, and the upper plate supports two short palmars. In the majority of specimens, both posterior rays have but tiuee arm.s, and only the distichals next to tho anal side bear palmar.s. The briu'hials throughout the calyx are provided with a sharp node or .short spine ; the plates of the two upper rows are in contact laterally. Arm facets large, lunate, and directed laterally; the audjulacral openings arranged in groups, the interspaces between tho rays being larger than those between their subui\!sions. Respiratory pores large. Arms sixteen to eighteen, .stout, rather long, and incurving. Near tho calyx they are rounded on tho back, bu. gradually increase as they flatten to twice tho diameter at tho lower end, and tho plates to twice their length. Each alternate plate at

4

I

n.vTorniN'in.K.

;iii'.)

bofli «i(li'>4 of tlio nrm is i)rniimentt»(l witli n xmnll uplno, nnd those BpiiiuH, wliicli arc iilaceil iiloiig tlio cidcH of tlio nrin», iiicroaMo in leiij^tli nnd tliick. ncsM u[t\vanl, Iiitorhniciiiul-t tliruo ; tlie first very larj,'i' nnd sj)in<ni.s, tiiu two nppor ones merely convex. Anal plate liiyher timn tiie radials, nnd covered with ft short central spine; the three succeeding plntes are niniply nodoso, while the tln-eo or four small pieces above are scarcidy convex, Ventral disk shorter than the dorsal cup, depressed hemispherical ; the ornls ami radial dome plates spiniforous; the interamhulacral plates nodose. Pos- terior oral very large and central ; nnal tube exccntric and quite slender.

Column large, the plates short. The older joints are twice as wide ns the intervening ones; the younger joints extremely short nnd flat at (heir sides. At 4 cm. from the cnlyx there nrc in one of our specimens seven joints to the internodo, nnd these occupy only 1 mm. in length.

I/iiriznii ami Lacaliti/. — Lower part of the Upper Burlington limestone, Burlington, Town.

Ty2>e in the White collection in the University Museum at Ann Arbor.

ErotmocriQUB corbulis (Hai.l). Plate XXXVI. Fifjs. Sa, h, c, ami 0.

18(11. Aflini>eri»m enrliiilif — IIaii, j rrclini. Ui'scr. of New Criuniils, p. 1, nml Boslon Jniiriml of Nnt.

llisl., Vi.l. Vll, p. 263. 1573. llilnfriiiin (l\i;tiii<ii-i-iiim) rnrhiili:) — 'S\f.yjk nml WoiiTIIK.V; Oi'dl. Rep, Illinois, Vol. V., p. SfiS. ISSl, ICri'/iii'irriiiii.t rui-iit/it — W. niul Si'.; Ucrlslim I'lilrencr., I'nrt II., p. I'll.

Cnlyx subglobo.so, wider thnn high ; the dorsal cup from one third to one hidf higher than the ventral disk, broadly truncate at the lower mnrgin. the width at the bnso cqiml to one hnlf the dinmeter nt the nrm bases, the sides gently spreading nnd slightly convex. Plntes nodose ; the nodes upon the radials anil brachials transversely nrrnnged, those upon the interbrachinl plates subcirculnr ; the surface smooth or obscurely granulated.

Base short, the upper mnrgin deeply notched nlong the sutures ; expand- ing outwnrd nnd downward, projecting conspicuously beyond the top of the column, overhanging it, nnd forming n broad, .shallow inverted basin. In some specimens the basals are so deeply notched thnt the lower angles of the rndinls, nnd that of the nnnl plate, constitute n pnrt of the projecting rim, nnd sometimes even enter the lower concnvity. Radials short, nearly twice as wide ns long, their nodes directed downward. First cost.als not more than half the width of the radials, short, quadrangular, twice ns wide ns long, their

I

;

\

1(1(1

IIIK • IIINolliKA CAMl.liAIA (»I' MilMII AMI.IIKA.

Idwlt faces convex, Si-cond cilsIuN |ii'iitiiii):;iiliii'. in width iiinl Iriigtii rt'^om* Miii;^ till' (lr.«if. DixliclmlH VMijiiij^ liiKii two tu llnrc. owinj,' to tlii.' iikiiiImt of iiniis in tlio .t|MM'inu II ; hiiiiiIIci' tliiin tlic custiil^, Wlicii llicif arc rniir iiniir* ti) ciicli iiiy, wliicli prolmlily i-* ll"' iiDrmiil iiiiiiilicr. llicv ron^ist of 'J X '2 pliitL"*, ami tli(-o lilt' fullowfd liy U X li paliiuiiH; when, liuweviT, wliiili in '|iiilu fi'e(|iiciiily the ea^ii', llie aiitci'iiir ray han only two iuiiim, il lia'< three Hiicce.Msivo di>ti('liiilM in liolli divisions, Spi'eiiiieii.M with three iiiiiim in the iiiilcrioi' iiiy ari! eoiiiparatively rare, in this case the oiie di\isiiin has tliri'e disiichals, the other two, I'alinaiM hhuit, in contact laterally, and iiniiided like arm plate.s, leaviiij^ loiij^itiidinal de|ire><,«iioiiH at their sirles. Ann ('acet,>i lai'jfe, iliii'cled outward ; the aiiihiiliiciiil o|ieiiin},'i elonj^iite, iilniost eijiiidlH- taiit, the iiitersiiace hetweeii the two |i()<ti'rii)r rays \ifh\y; a little the widest, Itesjiiratory pores large, separated i'loin the ainhiilacriil juissnges liy thin par- titions, which I'reipieiitly are not preserved, Anns eijj;hteen to twenty, stout, loiijr. ineiirviiijr and hiserial. The lower portions of the plates are roiiinled, mid every third plate of hoth serieH is e.xtended lo roriii a short lateni! spine; till.' upper portions f,'radiiiilly j^row Hat, and increase in wiilili to twici? that at the hottoin. Init do not attain that .>-liarp Unil'e like ed;,'e oliserxed in some species of this jrciiiiH, liiterhraidiials rr<iiii one to three; the (irst very larjie ri-iiijr to the top of liie first disticlials; the njiper plates, wlnn present, \ery iniiHite. Anal piec(! hi^'her than thoradials; succeeded liy three larjre jilates, and tli''se soiueliliies hy one or two small ones. \'eiitriil dl>U depressed leiuispheiical ; llie plates highly r(Mive\ or nodose. I'o-leiior oi'al strictly central, fully twice ,is large as any of the other plates, and surniouiitcd liy a high node, 'I'la^ four other lU'als and the radial dome jiliiles are c(uisiilei'- alily larger and nuui' prouiiiieiil than the inlerjiiiiluilacral |iieces, some of which are (piite small. Anal tube excentrie anil very slender; it.s length not known. Coliiinn near the calyx composed of high joints, nngiilar along their edges.

/f(irir:on kikJ Ijimfih/. — Lower Burlington limestone, Ijiirliiigton. Town, and Lak(> Vallo}', New Me.xico.

7}/jtrs in the INInsenin of Comparative Zoiilogy, and in the University Museum at Ann Arlior.

ficmarhx. — This species was dcscrihed by Hall as having twenty arms. Among twenty-one sjiecimcns in onr collection, which all undoubtedly be- long to it, there are ten with twenty arms; five liavo nineteen, and .six but eighteen. The deficiency alway.s occurs in the anterior ray.

1

HATUdnXID.K.

401

ErotmoorinuH louooMla (IIai.i),

I'l.ilc AAA 17. /'V. In, h,r.

nil. ,/c/M»cci'»»» t'liiWu — llu.i.; rnliiii. Dimi. cif .Ni\* C'liu , |i. I, iiuil ll'iiinii Juiirii. uf Niil. !|i-i ,

VmI VII, |.. ii\\. 1S77. //.(/..•(•i»,i /,•«,•„.(,/ S .\, Mii.i.m; Aniir. I'hIiim/., K':"'., p. 07.

|S'(I, Unliiiiii-riiKU Inifmi'i — \\ ■ iiihl .^l'. i llcih I'iiImiici., I'lirl II., |i. I7'l.

|si:t. liifliMfritiHt lf¥:iiuii — i*. .\. Mii.l.Ht; Aimr. riiliin/., Kn-". (Nc.md Kilil ), p. 8SJ.

Sjrii. /'" ■^'•riHin fiiHj'tiiiiiiniiy S. .\ Mil.r KH, hUl ) (ic'dl. Niirv. Minvmrl, Hull I., p. Ill, I'liiti' S, Fiir*.

Uiiiull:). B^ii. IMuetimit Miii-i S. ,\. Mii.lKli, W'M, Adv. Hlicrl, iMli lie p. fiml. Siiiv, IriiliMiiii, p. .TJ, I'liilii t), Fiu'< 7 Ml.

Of the Ivpc llf h'.ri liiliiii'iiiitx ri'ihnli.-t, lillt ll liir;,'!'!' H|)f'ci('H. f^':il)'X i\» lii^rli ns wiilc, ill liirj,'!' Mpt'cinicn.s HoiiKnvliiit, wider; llic riiys sii;ilitly lolicd at, tlio ni'iii I'cj^ioiiH, mill groovi'il nt. tlio iiiiiil side. DorMiil cu]) lirondiy Iniiii'iilcd iil till' liiisc ; llic NidcM iinironiily ."prcudiiij^ from tlii' top of llic Iiii-!i1,h, I'orming a Mliiiijj:lit or very .'»lij^litly (miiiciivi! lini! to llii' Im.^cs of tliK iirriiM. I'liitc.M iiiodL'iiitrly (!oiivi'.\, witlioiil oriiiiiiiciidition, tlio .'iiitiiri' lines grooved mid qiiii" disliiiet,

ilii.>((' .hIioi'I, projectiiij^ oiitwiii'il, ;iiid roniiiiig a sidieiit, trilolmti' rim wiili HJimp lower eijjriM ; iliu lower I'liee perfectly Hat CNcept in the iiiediaii pail, wliii'li to one third the ilimneter at tins liottoin i.s ,'ili;,dilly excaviited ; tlii! axial iMiial lai'^'i* lor thi.-* <renii.-i, mid pentangular. liadials liir^r(i, once and a half a.s wiile as loiii^, the upper face concavo. First co.slals i|nadraii^ii1ar, and small as coiiipared with tliu radiuls; tho second wider and |)enlaii;(n!ar, unless they are touched hy iho second row of inferliracliials. which is e\<'ip- tionally the case. Dislichais two, short; lollowuil in four of the rays hy two exceedingly short, transverse palnmrs, which sn|)port tho arms ; in the ante- rior ray, which has no palinars. directly hy the arms. Ann facets very large, directed .-lijrhlly upwards, and arranged in groups. The iiiters])aces lietween the rays coii.-^idei'uMy wider than tho.se hetween their .siihi]i\i«ions. and Homewhat grooved, especially at the anal wide. Arms eighteen. iiia.«.'^ive. long, incurving, and hiserial from the cal^'xiip; they are given olf in pairs, and the two ariiis of eaidi pair are siitiirally connected to the height of the third arm jilate. For (piite n distance from tlie calyx, the arms are evenly rounded at the hack, hiit they grow flatter toward the tips, and increase Home little in width. Tho arm plates are moderately short, and every fiflli piece in Itolh scries i.s provided with a lateral spine. The spines near the calyx are quite ."liort, hut those in the up[)cr regions attain a length of 4 mm.

•I V

402

Tlir, ( KINOIDKA CAMKItATA 01' NOliTII A.MKUICA.

Iiifoi'lit'acliials oik; iiiiil two, tlio first iilriiosl t\n lar^^c iis tlic riuliiils, tlio two U|i|)('r oiui.s fillicr iirclicd l)_v the |iiiliiiiirs, uv I'dllowi'd \>y an udditional cloii- gatt; pircc, wlii'li is iiit('r|i<is('(l liclwccii ihu paliiiars ami (•(iiim'<'ls w illi llii' intenniibulacral jilalcs. Anal |ilato iianowci' ami liij^licr than llic radials, hii('('('<mIc(1 ]>y tliri'i! laij^c, soiiicwiiat I'loiijralc platen, wliicli wiipport two or tliri'(! .smaller ones, and these another which rests hc'twcen the arm liases. N'entral disk a little lower than (Ik; dorsal i-iip, irrejrularly hemispherical; plates eon\ex, th(! orals and radial dome plat<'s ol' the tegnien larger and more piolidierant than the intervening plates, the posterior oral nearly Central and twice as larg<' as the I'onr others. 'I'he radial dome plates ai'e jilaceil near tin- periphery, there heing three large pieces over each lay, one aliiive each arm p.'ur. e.M'ept in tlu! anterior ray, in which there is lint oiii' piei'c. An;d tnlii' large, snhcentral, compfiseil of nodose ]ilates. Strneture ol arms n<it known.

//('linn iiiiil Liiiiirilij, — Ijower IJnilington limeslone j lUnlington, lown, ond Sedalia, Mo.

Ti)i)i in the University .Mnsenm at Aim Arhor.

ErotmocrinuB rugosus W. ami Si. (nov. .spec). /'I„U AAA 17. /■Vys-. /y,^ \,. r.

A small, well marked species of the type of /'.n Inuifrliiiis /inciiKin. Calyx wider than high, distinctly loliid at tin; arm regions. Dorsal (uip depressed, broadly trnncal(' at the hase ; the sides, whiidi at their lower end spread lint very little, espanil ahrnptly from the top of the costals. and form a rim, whicii is alnuisl at right angles to (he liiise. i'lates highly elevated; the radial ones I'ormed into conspicnons ronnded riilges. which extend to the entire width ol the plates; the interr.adia! ones into ronmleil nodes, 'i'hi! snrfacre of th(! ridges is covered hy small, elongate prominences, forming longitudinal rows; the top of the interiadial nodes hy similar excresci.'nces which have a radiating tendency.

Hasals extretimly large, spreailing outward anil riownward, and forming a liroad rim, of which tiiesntnre lines are di'cply indenti'd at the sides and distinctly grooved at the lower face; th<' snrfaci; of (hi! plates np to the column facet is <■ ivcrcd hy line, rugose stria'. Iladials short, mor(^ than twici; as wide as long, (.'ostals narrower and shorter than the radials; tin; first (piadrangiilar, the second pentangnlar. Distichals 2X2, smaller tlnni the

V »

ItAIOCUIMD/K.

403

co.stals; followed by 2x1 ])iiliniirs, except, in llio nnteiior my, wliieli lias three tli.sli<'liii],s uiid no piiiiiiai'.s. Arm I'acelH large!, projeetiii;^, (lireeli^l out- ward. Ann o|)eningH arranged in j^ronp.s; the inlcMspact^s helwccn the rays twice as wide u.s tiie olhern, and Hli;,(ht,ly dcprcsscMJ. Ainm ei;(litcen ; their Htrueture in not luiown, hnt they were evidently large. Interradial.s one; or two, very .small, and archeil hy the palmar.s. Anal plale shorter and nar- rower than the I'adials; it i.s followed hy three; and one plate of nearly ei|ii(d Hize, and hy a narrow elongate piece at the arm regions. Ventral disk ahont as high as the dorsal cnp, hemisph(>rical, .slirhtly linlging along the siiies, the principal plates sharply nodose. Posterior (ii;ii strictly c(tntial, more spinons ;md larg(M' than the I'onr others ; the radial dome plates arrang(;d in groiij).s of three over eacli ray. Anal tnho exeentrie and very nmall.

I[iin::iin niu/ /jui'dli/i/. — Lowt'r Itnrlington limestone, liiirlington, Iowa.

'J'^jii/i in the collection of Wachsmuth and Springer.

Erotmocrinus coronatus (Ham).

I'/tllr XXX I'll. F;,js. 7'I, h,r.

l>^(i(|, .ti'/iiiiirriniit roroiiiitiix — llAr.i,; Sii|i|il. (Iinl. Ili'|i. Ihhii, |i. '2s, riic]li}i;r, I'liilc I-, Kip. 1 aiiil i

(h(2, N. V. Sliilr Hull. I.), llfil. l\rihiiiiiTiiim ri)riiniitu.i — .Mkkk .■iniI Wuhtmks ; (irul. lli|i. Illiiiiji'., Vul. V., I'liilc 10, Fiu's.

S,(, h, e. 1S77. /trtiitinTiints fiirinmtiix — S. ;\, Mri.r.Kit; Aiiht. I'iiIji'm/., t'nss., p. (W,, ISSl. I'.rilainriiiim riiiniiiilin- \\. Mini Si'., Ili'liviuii l','ilii'i.iT., I';irl II , |i XIW. |S'.)(I. ilirliiiiii'riimn rtii-niiiiliiH - S. A. .Mm.i.ku; Nurlli Aiiirr. (Jicil, ,'iiiil I'lilircml , p. isi.

A sonu'wliat, aberrant form, in its general hahitns appicdiching P(ii]'/rr!iiiis, Caly.x about as high as wiile. Dors.al cnp a little slKnler than the ventral disk, broadly truncate at, the lower end, wlieri! its diiimeter is e(|u;d to one half the width at the top; a little lobcd at the arm regions. The |)lates are highly convex or nodose, the sutm-e lines disi'ncl.

ISasals .stretched out hori/.onlally, and sometimes hidden almost entirely by the overhanging nodes of the radials; they iire deeply no(<'hed .'il the suture lines, forming a sort of Irilobeil plane, which in the ceiilral part is .slightly excava(e(l for the reception of a very small <'olunm. Ilaclials modc!- iitely largo, the two he|)tagonal om-s with sharp salient angles, which (it in and rest within the lobes of the basal disk, and form a part of the lower •surfac^e. First costals (juadrangidar, twice as widi; as long, nai'rowcr than till! radials; the upper ami lower faces Htraighl. Second costals pentanguliir, generally a little longer than the first, and somewhat wi<ler. Dislicluil.s two;

llli

404

THE CKINOIDEA CAMERATA OF NORTH AMERICA.

tlio upper one very short, loaf-like, aiid supporting the arms, except in the two posterior rays, in which the distichal next to the anal side is axillary, and supports on each side a single palmar, thus making the number of arms in these rays three, against two in the three others. Arm facets very large, directed obliquely upwards. Ambulacral openings elongate, arranged in groups, the interspaces between the rays twice as wide as those between their subdivisions, and at the posterior side almost three times as wide, and somewhat depressed. Structure of arms not known, but, to judge from the size of the facets, they were unusually stout, and were biserial from their origin. luterhrachials one, elongate, very large, arched by the arm-bearing brachials. Anal plate longer than the radials, the lower angle sharp and extending far down into the basal disk ; it is followed by three large plates, and there is a smaller one between the palmars, which connects with the interambulacral pieces above. A similar small plate occurs exceptionally between tlie distichals at the other sides. Ventral disk depressed hemi- spherical. Tiio orals are raised into short spines or sharp nodes ; the posterior one central in position, a little larger, and less spinous. The radial dome ]ilates, which are fully as large as the orals, and are also extended into spinous nodes, are placed around the periphery; there is one of these plates over the anterior and each antero-lateral ray, and three over the two poste- rior ones; the spines are directed slightly outward, and give to the tegnien tiiat peculiar coronate aspect which is so characteristic of this species. Inter- ambulacral plates PiUiill, and merely convex. Anal tube subcentral, very small at the base, its length not known.

Jldfi-jiin ami LufdlH'/. — Lower Burlington limestone; Burlington, Iowa.

Ti/pe in the (Worthen) Illinois .State collection.

Eretmocrinus intermedius AV. and Sp.

Plate XXXIII. Fi</s. 2a, h, r.

1S81. W. and Sp, ; Revision Piilirocr., P.irt II., |i. 174.

A small species. Dorsal cup broadly truncate at the bottom, the sides straight or slightly convex. Pliites almost flat ; the radial ones marked by indistinct ridges, which pass into the arms; the interradial plates covered with a small central node, and all obscurely (luted toward their margins.

Ba-'e sliort, broad, slightly projecting laterally, rounded along the margin, indistinctly grooved at the sutures, the lower surface excavated, and to one

4

BATOCIUMD.E.

405

1

half its diameter occupiecl by the coliimn. Radials large, a little wider tiiau long, the upper lace concavo. First costals narrower and whorter than the radials, twiee as wide as long, upper and lower laces convex. Seconil costals generally a little longer than the first. Distichals 2X2; followed in the three anterior rays by two rows ol two palniars, which support four arms; in the two posterior rays, in one or both divisions, at one side by one palmar and two post-palmars, at the other by two palmars, a structure which gives to these rays live to six arms, or twenty-two to twenty-four to the species. Arms stout, long, incurving, and biserial from the second free plate ; they gradually increase in width, being at two thirds their length more than twice as wide as at the base, and perfectly Hat. Also the plates increase upwards in length, and their outer faces become transversely angular. Interbrachials two; the first very large, the other quite small. Anal plate followed by three and two pieces. The upper row at all five sides is arched by the palmars and post-palmars. Structure of ventral disk not known.

Ilorium and Lomlili/. — Upper part of Keokuk group; IJono, Lawrence Co.. Ind.

Ti/pcs in the collection of Wachsnuith and .Springer.

Eretmocrinus praegravis s. A. Mn.i.m. rhde XXXIV. Fi,/s. 9, 10.

1S9J. S. A. MlIXKH; Ailv. Slurls ISlh li.p. Cc.il. Suit. Imliiuia, p. .V, Thilc fi, riir*. 5 nnd fi

A large, very knobby an<l roliust species, in its ornamentation resembling Jjihdi'riiiiis Vitiii/i/Zi ; but the calyx more globular, less distinctly lobcd. and with a dill'ercnt arm formula. Dorsal cup sauccr-sha])ed. abruptlj' spreading from the base up, the plates heavy and covered with largo angidar knob.s, some of which are arranged horizontally, others longitudinally.

IJasals short, forming a hexagon with acute jMigles ; the lower surface slightly excavated for the reception of the coliunn, and pierced by a com- paratively large axial camd. I^iidials twice as wide as long, covered with prominent transverse no(l(>s. whose tips reach to the level of the lower margins of ilio basals. The node of the intervening anal is round, and the plate itself longer than the radials. First costals linear, less nodo<e than any of the other caly.v plates, and sometimes completely flat. Secoivl costals smaller than the first, depressed pentangidar ; their nodes subtriangnlar. The posterior and anterolateral rays have but one distichal in their posterior

i n

>!>'

I

400

TIIK C'lUNOIDEA C'AMKRATA OF NOKTII AMKUICA.

divisions, whicli is followed by 2 X 2 iialinar.s and two arms ; but in the antoiior divisions by 2 suecessivo distichai.s and a single arm. The anterior ray, wiiieh has but one arm in both divisions, has 2X2 distielials. Arm facets Eubcircular, conrave, very large, and the surface covered with radiating striiv. Ambulacral openings cjuite small. Intcrbrachials: 1, 2, 1, 2 at the regular sides, and l», .'!. 2, 2 on the anal .side ; the upper row on a level with the arm bases. Ventral disk inllated, considerably higher than the dorsal cup, the conical upper end passing gradually into the anal tube. The plates of the tegmen decrease slightly in size toward the peripher}-, and arc covered with sharp nodes as large as tho.se of the dorsal cup. Orals excentric ; the l)osterior one quite large. Anal tube stout and composed of large ])lates with sliarp elongate nodes; it is almost central at the base, but curves a little to one side. Structure of arms and column unknown.

Jfiirizwi and L'lcn/i///. — Keokuk group; White's creek Springs, near Nashville, Tenn., Pilot Knob, near Louisville, Ky. ; Barren Co., Ky., and New Koss, Montgomery Co., hid.

^

ALLOPROSALLOCRINUS Cass, and Lvojf.

1800. Casskhvv ami Lvos; I'rocoi'd. .\iiiit. Acad. Ails ami Soi., p. 29.

isrif). SinMAiiii; C.ilal. I'aln'nz, Fuss, Nmlli Aiiut., Part I., p. HjH.

Isra. -MttK and WoRTiiKX (in part); GcmI. liuji. liliuuis, Vol. V., p. 3(JS (not .M. ami W., 1S65, rrocccd.

Acad. Nai. .S'i. I'liila., p. llit). 1^7'.l. ZiTT>:i.; Ilamlli. dcr ralii'niilcilni^ic. Veil. I,, p. ;i70.

l^^l. \V. and 8r. ; l{c\i>ion l'alnMin-., I'art II , p. U'i (I'rcironl. Acad. Nat. Sci. Thila., p. 2S7). 1^'JIJ. S. A. Mii.i.i u; Xnrtli .Vnnr. (iciil. ami I'aliront., p. Hi.

Svn. Oiii'H-riiiiix TJlllll^T; List uf Criii. of Tciin. (iKil defined).

Calyx conical, almost flat below the iirm bases. Basals three, equal. Costals two, but generally so closely anchylosed that the lino of luiion is invisible, and there is virtually but one j)late. Distielials one or more, either followed by palmars, or directly supporting the arms. The arm-bear- ing plates in contact laterally, except upon the anal .side, where they are sep:irated by the second anal. Arms few to the ray, arranged in groups; their facets very largo, siilicircidar and deep!}- notched at the upper end for the receiition of the ambulacra. The interbracliials, so far as observed, consist of one large plate, excejit at the anal side, where the first amil is followed by a second, which at each side has two short interbrachial pieces. A'entral disk conical, its upper end gradually passing into the anal tube, which is stout and almost central. The ambulacra subtegminal, their main trunks covered by superimposed interambulacral pieces, whicli arc followed

IE.

f

nATOf'RINIDJE.

407

"Im

by a large mJiiil plate at each bifurcation. TIio orals pushed anteriorly. Respiratory pores arranged in ten pairs, live of them placed between tiie rnys, the live others between their main divisions; they are well dediied, and occnpy the margin of the ventral disk, a little to one side ol" the ambu- lacral openings.

DUlnliutidii. — The only known species occurs in the Keokuk group of the Mississippi \'allev.

Juimirhs. — The genus AffaprosadDoriiiKs is most remarkable for the short- ness of tlie dorsal cup contrasted with tlie great height of the ventral disk, in which it resembles Ai/drinirriiiiis. The form of the arm facets in the two genera is also quite similar, and they probaijiy had the same kind of arms ; but in Arjiiricocriiuiii the anus ojiens out laterally, directly through the disk. while in AlloprusdUocriniis it is placed at the end of a tube, and besides, the former having two well defined costals.

Meek and Worthen's J/Ai/^/vasy^/A/c/'/jk^s ciicmiun is a Dizj/gnrrliuix; it resem- bles the former somewhat in its form, but it has two costals, the arms are comparatively thin, and become paired in mature specimens.

Casseday and Lyon's Alldprnsdlhirrmus drprcKsiis is probably an Ai/an'ro- crinits ; the type specimen is too much distorted to admit a correct t'.iiignosis.

AUoprOSallOCrinuS COnicUS Cass, and Lvov. PUitv XLII. Fiip. J4u, h, r.

ISfin. Casskd.vy anil IiYon; rrocccil. Amor. Acad, of Arts and Sci., Veil. V., p. ifl.

180C. Siil'SI.\itIi (SuligLMiiis 111' Jrliiiocrinii') ; Calal. I'alii'ua. I'oss. (Trans. Acad. Sci. Si. I.iiui«, Veil, II.,

p. lioli). 18S1. W. and Siv; UovUinn Tahvncr., Part II.. p. 1 1 1 (I'lMcci-d. Acad. Nat. Sci. I'liila.. p. -.'S"-)

All'ii>rusiitliirriiiii!i Ciiririii S. A. .Mii.i.ivK', Is'Jl, Adv. Slarli 1 Till l(c|i. (icul. Siiiv. Indiana,

p. ,J8, rialc in, I'igs. 1 and 2.

Calyx pyramidal ; the dorsal cup so flat that it is filniost invisible from a side view ; the ventral disk high and distinctly conical. Plates thick and devoid of oriiamentiition ; those of the dursid cup ver}' slightly convex; the plates of the tegm?n varying fnun convex to nodose.

Basals small, forming iin inverted hexagonal biisin. Radials wider than high, the lower portions bending inward, and forming a part of the basal concavity. Costals generally so closely anchylosed that a suture line ciiunot be traced, both together are pentangular, a little wider than the radijils, and wider than long. Distichals 2X2. except in the posterior rays, of which the divisions next to the anal interradius have but one, which is axilhiry iiud

I ^\

V»l

408

TIIK CinXOIDK.V CAMKRATA OK NOUTH AMKIMCA.

supports 2x2 fixed pnliunrw, and these tlic arms. The anii-boariny i)lntef< are onee and a half as wide as those below or above, and in contact laterally. Their facets arc irregnlarly crescent-shaped, and directed slightly upward '. they do not occupy the middle of the plates, but lean to the inner sides of the rays, and leave large interspaces between adjoining rays. By means of this structure the arms are i'ornied into groups as effectually as in other species by the interposition of interbi'achial plates. The arms, which have not been observed in tlii.s species, were evidently quite ponderous to judge from the large size of their facet.s, and comj)0.«ed of two rows of short, leaf- like pieces, similar to thofQ o{ A(/arir(icriiiiis. Interbracliials one ; the i)lato large, higher than wide, and arched by the arm-bearing brachials. First anal plate followed by a very long second, which rises to above tlie level of tho arm bases, and rests between two .short interbrnchial pieces. Ventral disk more than tliree times as high as the dorsal cup; the plates largo and of about uniform size ; the anal tube occupying the central part. The posterior oral is the largest plate of the tegmen, and, like the other orals, is pushed over to the anterior side. The andjulacra are subtegminal, their upper portions being covered with superimposed iuterambulacral pieces, but on approaching the arms by large radial plates of a first and second order. The respiratory pores are large, and placed at some distance from the ambu- lacral openings.

Ifirir-iiH (tnd Lnonfifi/, — Keokuk group; Pilot Knob, near Louisville, Ky. ; White's creek, near Xashville, Tenn., and New Itoss, Moutgonu'ry Co.. Tnd.

lionar/is. — Miller's AUnpromlhiorhiU!^ (iiirh;/i is a small example of .^1. cunicus, in which one of the posterior rays has but two arms.

EUTROCHOCRINUS W. and Si-. (nov. gpn.).

(Kt well, Tpo^ds a wheel, Kptvov a lily).

Cal^'x largo, wheel-shaped, narrow to the top of the radial.*, thonoo .spreading abruptly until the sides of the dorsal cup are at right angles to the axis of the calyx. Ventral disk almost (lat to near the base of the anal tube. Basal cup deep, subcylindrical, compo-ed of three equal plates. Kadials larger than both eostals together; the first costal transversely linear, the second depressed pentangular. Distichals and palmars increasing in width upward. Ambulacral or arm openings equidistant or nearly so ; directed sidewise. Arms single or in pairs, bi.serial, loimded, very short and

nATOCRINin.E.

•10',1

■•Kiji

incurving ; piniiiiloa closely packed. Interbrncliiiils variable in ninnber, cither arched over by the higher brachials, or in contact with tiie inter- ninbulacral pieces. Interdisticlials frecinently represented, and occasionally interpalinars. Anal tube stout, central and extremely long. Orals e.xcen- tric ; the posterior one much larger than the others and erect, forming the base of the anal tube at tiie anterior side. Column round, with a small pL'iitanguhir canal.

lUsirihiilion. — Restricted to the Upper Burlington limestone and Keokuk group of America.

Type of the genus. — Kiifriirlincriiiiis Chrhtiji (Shumard).

Jiiinnrh. — Kiilrovltucrninx approaches J)i:y/ijocniiiis in its arm structure, i)ut difTera fii-'n it es.sentiall}- in other respects. In Birji/ijucrliiiis the calyx is .sul)globose, lie tegmen high, the arms rather long, the anal tuljc short and slender. In Kiitrochocrinm the calyx is decidedly whcel-.shaped, the ventral disk almost flat, the arms very short, and the anal tube extremely long.

EutrocrinuB Christyi (i^iu mai!i>).

riak XXIX. Fkj. 0, awl Fltitc XXXIJ. Fins. ]u, h, c.

ISi''. Ji-tiiini-i-iiiilfs — riinisTv's Irllors on (iL'(ilcif.'v, I'liile I., Tijjs. 1 mid 2.

1S55. li-liiiufriiiiii Cliii'li/i — i>iirMAiiii; (iudl. Idp. Missouii Ijv Swiillow, rnrt II., p. 101, rinte ./,

Y-. -A. IS'S. 'iii/m-riiiiis Cliri>li/i — JIfek niid WdiniiiN ; firnl. lie]). Illinois, Vol. V., I'liitc 5, Viijs. •!(', b. 1S7S. Itidm-i-iiiiis Clii-isli/i—\S. ami i^w; rnicTcil. Acail. Nat. 8ci. I'liilii., f. 231.

]S><.'). .Ir/iiiorriiiii.i Clii-ixli/i — QrKN.sTHlii ; llaiulli. del' I'clRfactcukuiidc (.\ii(liigc .1), rintc 77, l'"i(,'. l- lb»l. .'Iii/ocriiiiis (7iri.tf//i — \V. and Sr. ; Uevisidu Valu'cici-., I'arl II., i). 106. (lot Jcfiini'Viiiw C/irix/i/i — lI.M.i,, IvfiH r = Prriecliucriiius liliilfiildi). ISjii. lUitnri-iiiM hisl,r(ii-lii<ilii» AViUTFUiLi) 1 -Mciii. AiutT. Mils. Nat. Ilist., 1S93, Vol. I., ji, IS, Plate

2, I'iu's. \, .'i. Syii. ll.Jy.-riiiis ,i//('axcu!iii Millkr niid Gluley, 1S91 ; Geol. Surv. Missouii, Bull. 3, p. 20, Mate 3, Figs. 1, •.>, i.

Ciilyx large, wheel-shaped ; plates thick and without ornamentation.

Dorsal cup almost twice as high rs the ventral disk; sides concave, grad- ually spreading to the top of the raliiils, and more abruptly thence to the arm bases ; plates nearly flat.

IJa.sal cup large, somewhat wider than high, a little thickened near the lower end, and projecting laterally beyond the sides of the column ; the bottom deeply excavated. Eailials quite variable in form, but generally longer than wide; the upper face concave. Costals small, both together not more than liaif the size of the radials ; quadrangular and pentangular. Dis- tichals and palmara in two rows; the latter larger than any of the other

1 1 n

:i \ I

•*•

:¥

WL.l^..

M

410

TIIK CKINOIDKA CAMKKAT i OF NOIITII AMKRICA.

bracliiiils. The upper row of pnlinnrs tlocply excavated for tlic reception of the free nrtns, niul tlie I'licet occupied by a iliininutivc axillary, and two small arm I ates, which support an arm each. There arc twenty arm openiugn, arrn.iged at nearly equal distances, an.l directed horizontally. Anna forty, two to each opening ; they arc short, infolding, comparatively thin, and composed from their bases up of two rows of short transverse pieces. Pin- nules llattened at their si<le~i and contiguous. Intcrbrachials three to five in three rows, the lower one la;ge, about as wide as high, the others snuill and arched over by the palmars, which meet laterally, forming a continuous ring. Anal plate elongate, followed by three, three and two jjlates. Ventral disk depressed near the periphery, the niedian portions gradually rising to sup- port the anal tube. Plates convex ; the orals and radial dome plates considerably larger than the interambulacral pieces. The orals placed ante- riorly ; the posterior one twice the size of the otlier four, directed upwards, and forming at the anterior side the ba.se of the anal tube. Anal tube extremely long, sometimes arising to a height of four inches ; thick nt the base, but gradually tapering until it is quite slender at the upper end. Column of moderate size, round ; the nodal joints rather high, cylindrical ; the internodal ones increasing to four at three inches from the calyx.

lliirir.im iiikI Londif//. — A characteristic fossil of the I'pper Burling- ton limestone ; Burlington. Iowa, and several other places in Illinois and Missouri.

Jtt)iif(r^:s. — Ei(/rof:Ji"crliiiis Cnxtj/i is very closel}' allied to E. Lovct, and unless the arms are preserved or the arm openings ver\' perfect, it is diflicult to separate them. That the two are evolved from a common type is well .shown by the fact that in young specimens of E. Clirktyi. one or two arms are frequently* simple ; while the larger ones invariably have two arms to each arm opening.

Eutrochocrinus Christyi, v.n. trochiscus (Meek ami Wokthex). Plate XXXII. Eiff. 3.

ISrtS. Tliilnivlims froelihfii> — Mkvk mid 'WnnTlir.x ; rrnrred. Aond. Xnt. Sci. Pliiln,, p. 354. Is73. Udtncriiiu' Irodii^ftts — Mkkk and Wdiitiikx; (icdi. Hep, Illinois, A'ol. V., p. .'(72, Phtc 5, Fiff. B. 1^78. Viir. cif lliiln,-r. Clirisli/i—W. imd Sr. ; rrocml. Acad. Kal. Sci. Thila., p. iM, njid 18S1, Kcvision I'alicocr., I'art II., p. IfiS.

Larger, and throughout more extravagantly developed than the typical form. Calyx more spreading and comparatively shorter, narrower nt the

' r

i;

UATOCUIXID.E.

411

base; tlic upper piiliunrs abruptly curving upwiirils, aiul tluuply cxciiviitt'cl to form the arm facets. Ventral dii^k near its periphery Hat or even concave, the plates nearest the tnar},'in highly tuberculous, projecting outwaril anil upward. Anal tube stout, composed of heavy plates, whiv'h are surmounted by a short central spine. Interbrachials numerous, consistin;; of from six to eight pieces at the regular sides, and of about eleven to thirteen at the posterior one. There are freciuently also from one to two interdistichals. Column conii)osLMl of large, rather high joints with distinctly convex edges.

Huriiun and LucnUtij. — Burlington anil Keokuk Transition bed, Des ^loines Co., luwn, and Nauvoo, Ills.

T'lpc in the Museum ofComjiarative Zoiilogy.

Ilcnwrlcs. — This variety forms a transition between EHtrudiwr'tnus Clirisitiji and E. j)lanuiliiiciis,

Eutrochocrinus planodiscus (IIam.\ I'/ale A'A'A'//. Fii/.s. 4a, />.

ISfiO. Jc/iiioi-niiiif I'liiiio'litrii.i — Hai.i. ; Siippl. ficul. \W\t. l(i\v;i, |i. 45.

1^73. Jlti/iivri/1113 jiliiihH/i.<i-ii.< ~ Mkkk iukI WniiriMX ; (ioil, Hep. llliiinis, Viil. v., p. .'tlir.

ls7S. /Ifi/otvi/iiis ji/iinui/ivHt — W. mill Si\, rnirnil. Acvul. \:il Sci. I'liil,. pp. 2:11 iiiiil i'i'i.

ISSl. llii/ucriiiiiii ii/,iiioili"'ii.i — W. iiml Siv j llivisioii I'lilinicr., I'liil II., p. 1117.

Of the typo of E. Cliristi/I, but more closoly approaching its variety E. trac/ilsriis, with ft greater expansion of the calyx than even in that form ; conical in the lower portions. From the first costals to the third pahnars the plates arc arranged almost hori/ontally, the post-jjalmars decidedly curve upwards. Plates slightly convex, their surfaces smooth.

Basals as in E. Chrktiji The radials comparatively smaller than in that species ; the costals larger, especially the second. Distichids in two ranges, as large as, or larger than, the costals. Palmars three, sujiportiiig tv.'o rows of largo post-palmar.", .separated by interbrachials, interdistichals, and fre- quently by interpalmars. Arm openings forty, eight to each ra^- ; sujiport- ing forty apparently' delicate arms. According to Hall, the species has fifteen intcilirachials in nine ranges, nine to eleven interdistichals, and five to six interpalmars. A specimen in our collection has only from six to seven interdistichals, four interpalmars. and about eighteen plates above the anal piece. Ventral di.sk depressed deeply concave, except the median portions, which support the anal t\ibe and are conical. The radial dome plates are more convex and larger than the intcrambulacral pieces. Posterior

'K

earn

412

TIIK CIMNOIDKA CAMKKATA OF N'lRTII AMI.IUCA.

ural luoje'ctiiig niul tlirec tii)iC8 no largo as tho fuur uthura, funning tlio bnso of till* iinul tube nt itH nntcriui- Mo.

Horizon and LomJilij. — Ktokuk group; Krokuk, Town, nnd Nniivoo, TIIk.

T'/iic in the (W(iitlii'n) Illinois Stiito collection, Springfield.

litiiifirlcH. — Tiiis fpi'c'ies iigrees fumlanientiill}' with L'. Chmfi/I, but Ims a much linger luuiiber of interlmichinld, nnd numerous interdistiehnlsnnd intcr- pnlnmr.x. which nro unrepre.iented in 7v'. C/iris/ffl, nnd n much grentcr expan- sion of the rim. It ill^o dilTors in having a huge axillary palmar, nnd forty well defined arm openings around the calyx ; while J'J. CJtrislyt with tho snme number of nrn)s Ims but twenty openings, n minute axillary, nnd two arms from each opening, riiylogoneticnily £. j>/fmo</l.sriis is n more ndidt form of/,'. Chi'iKti/i, but from n clnsKifioatory standpoint must be regarded as specilically di-tinet. The development of the rim from K Clirlxti/i with its twenty arm openings nnd double arms, through £. iror/iiscits to J'', phmo' (liscits, with its forty independent nrm openings, wns coincident with tlm geological succession of the three forms.

T

EutrocbocrinuB Lovei W. mul Sp.

r/uir XXIX. Ftr,. 7, ami Plate XXXII. Fir/s. 2u, h.

ISSl. Jliitorriiiim f.ni%! — W. nnil Sr., Hovisidii riilivcior., Pni't II., |ip. I" nnd ICiS. 18'JO. liiilwriiiits lMi;i — S. A. MlLLtUj North Anicr. Gi'ol. mid riila'oiit., p, 228.

In its general habitus very closely resembling Eulrochncrimis Chmli/i, but n smaller species and differing es.«ontially in tho arm structure. Cal^'x wider than high, tapering abruptly to the poles, the sides convex. IMates without ornnmentatiou, flat in the dorsal cup, convex on the ventral disk.

Bnsnls forming n large conicnl cup, of which the lower face is occupied completely by the column. Radinls larger than both costnis together, about as long as wide, a little widest nt the top. First costals small, quadrnngular, twice as wide as long; tho second somewhat liigher; their sloping upper faces forming n right nngle. Distichnis nnd palmnrs in two rows of two plates each ; the latter larger than the former, nnd the nrm-benring second palmnrs wider than any of tho other brachials. Arm openings eighteen to twent}-, narrow, directed slightly upwards, and nrrnnged in groups of four — two in the nnterior rny — with a shallow depression between the rays. Arms eighteen to twenty, single, .short but somewhat larger than in E. Clirix/i/i ; composed from their bnses up of two rows of very short pieces.

I

i t:

hatochinid.k.

•113

Pinmilus proportioniill} Inrgo. ItiterbiKi'liials two to tliree ; tlic first i[\\\Ui Jnrgo, riniii^' to the top of the firnt distii'IiiilH, First niml pIiUu imnowci' tliiin till! rmliiilM ; followed hy two rows of tliroc plates, wliicli uro arelieil li)- the piiliiiarH. W'litral disk depressed convex, tliu iiiteraiiibidacral spaces wliglitly depressed ; the orals and radial dome plates ((insidcralil}' larger and more convex tiian flie intervening plates. Anal tubo composed of almost flat pieces; central, rising considerably beyond tlie tips of the arms.

I/iiri'znn riml Lumlitij. — Lower portion of the I'pper Burlington linie- Mtone ; Burlington, Iowa.

Ti/jHH ii) tlie collection of AVnclismutli and Springer.

DIZTaOCRINUS W. nn.l Sp. (nov. gm.). (Ai'fi'yn? two nlircast, Kfiivnv a lily).

Calyx dopressed-subglobose, biturbinato or snbconical ; (be ventral disk generally as liigb as tlie dorsal cup, and sometimes considerably higher. Plates smooth, granular, or obscurely striated. Basals very short, forming n slightly projecting circular rim or shallow basin. IJailials proportionally smaller than in Hutdrnims ; the first costals quadrangular, the second pen. tnnguhir or rarely heptangular. The npper brachials either form a con- tinuous ring around the calyx, or arc separated (rarely) between the ra3'.s by a narrow inti'ibrachial piece; the faces supporting the arms are excavated into subcireular or lunate facets, which are directed outward. Arms long niid bi.serial, given off froni the calyx eithi'r singly or in pairs. When the arms are paired, they start from a diminutive axillary, and the proximal arm plates and this axillary rest upon the same facet ; when simple, a largo cuneate jdate takes the place of the three .small pieces, llegular interra- dials from two to four, at the anal side five to eight. Anal tube almost central, .slender, and rarely rising above the tips of the arms. Respiratory openings small.

JJislriJiiifwn. — This genus, so far as known, is restricted to the Subcar- boniferous of America; it is represented in the Upper Burlington limestone by four species, reached its climax in the Keokuk group, and disappeared in the Warsaw limestone.

I'/jpf of the genus. — Dkyij'icrinm tiuliaiiensls (Lyon and Casscday).

Hcmarks. — Most of the species for wdiich we propose this genus wore described originally by Hall under Acllnocriiitis, whence they were removed by Meek and AVorthen, and placed under Butocrinus. Dizygomnus cucomm

^

J.

Ill

Tin: ('l!iSolI)|;.V CAMr.lfATA OF NttlMll AMF.KICA.

wax lU'sciiltiMl ]>\ Mi'ck ami Woillu'ii as an Al/i>j>roiiitliocrint(ii, iiiul D. I'l'njl- Hiin'iis ail ■ />. iiilii/ti(s, wliii'li liiivo «liglitl_)' n|ialuliito aiiii!', ])y uh iiiiilcr /Jfiliiitirrliiiin.

Tho iiidKt noli'woitliy fiat mo of J)iy/i/i>criinis in pioni'iitcil hy tlie Ktnic- tui'c (if tlio anii.M ill llu'ir toiidoncy to iiiuitiplicatiuii, a [» ciiliaiit}' in uliioh it tlin'fr.>< fiom all itllicr known j^ciu'ia cxci'iit Kiili'nhocriiim ami Jhiii/iiiinin.

It \inH hooii sii|)|ius('(l tliul llio nuiiihci' of aniiH, ami tlii'ir (li.stiilnitiun Minoiii^ till- ray.x, alToidod cxci'llrnt cliaiactors for cpvcific Hi'jiaration, u riik' wliicli ('ciiiiinly lines n<it apply to this gi'iiiiM. Among tiic fpft-ics Mhicli wo rcfi'i' to it, >onu' spcoiiiioiix Imvo twitu- as many arms as others, nnd wo finil any intuiinuiliato miinlior iR'twfcn llu' two oxtivmos. If it woro tnio that all thoso variations wi'io of spocilic impoilniicc, tho nninbor of species in this genus would liavo to ho iiuMeased to tho niimlicr of permutations and comliinalions lliat would ho mathemnticiilly i)()ssilile out of tho fourteen single and douhlo numhors into which those arms may ho urranged. In Dhiiifin'liiiia iiiiilii/i!lis every speciini'ii in our collection — seven in all — would constitute a dilToront species, as shown by tho following formnkt' :

1. 2. 1, 1 Z

1,1. :', 1 1'.

, 1. .1,

1'. 1.

• > O <» I O •) o

I* •» t» I •» *i *>' ZLZLT* I *' «> "I

2^1. 1, I 1, l.'J, 2. 2. I, 11', 1,2.

2. 1. 1. I 1. 1^,

STTTl;. I I. "I. 2.

1. 2.

2JI^1, I 1. I.^

1^.2.1 ■-•^

2. 2.

2, 2^1. I 1,2,1,

2, 1 2, 12, 2,

2,T.

I, ., -, I ., I, «,

1, I. 1. I 272.

2, i:

A careful study of these specimens shows that they nil must helong to tho Slime species. They have fourteen arm openings (exceptionally thirteen), and an ocjiial nunilu'r of arm facets ; hut while some of them have paired arms, others have single ones. In ."ome species of this gi^nus, tho arms are more fre(|ucntly either all .single or all paired, but ninoiig them also transi- tion forms occur; sometimes one or two arms only being single or double, and again one half of them. As a rule, the .■'pecimons with single arms arc smaller, tho arms .stouter ; but in other respects they I'osomhlo those with paired arm.s so closely, that they cannot be recognized from the calyx alone. This has induced us in some cases to refer both forms to tho same species, but to distinguish them by nn appropriate variety name.

A

r

i.

hatuchimd.i:.

415

T

nno.

b7:i.

Dlsygoorinua indiaooniU (r.v<>y uiwl v,\->* ).

rink XXX nr. njn. cu, />, un,i rtui, xxxv., Fi,j. ,i.

Ji'liDofrimii imliimemii — Iaom •ml Cahu i Aiiirr. Jourii. Si'i., Veil. XXIX , |i *.V .<i7i((wYi'/<((i i/«/(i/».'/i,<ii — Mkkk unil WiiiiiiitNj (ii'i)l. l(c|i. Illiiiiii'-, Vi.l. v., |i. ;IM> HiiliirrinHf iHili,iHeii»i< — \V. iiiiil Hi.; llin-inii I'lilirmr , I'liit 1 1 , |> I'Wl.

I

ItSl. Jl,i/u<riii».< (Wii/».//.t/i — (Ji t.>>ti'lii 1 lliiuilli. ilcr ritrilliclc iikiimli', I'liilc 7", Kitfi. Hi'. *.

Ciilyx bi'low iiu'ilimii si/,". l)itiirl>iii;ito to mu1i;;1(»I)()>('. iilioiit iim wide ns liij^h ; llu! (Iiiriiil cup ii little liij^licr tliiiii tlif vciilnil ili.xk. 'I'iu' f-iilc?" i>l' tin* (Mi|) cliglitly ciiiivfx, c'X|)imiliiii; nlmost imiftirinly from the Ihimc to tlic nrtu regions ; the nxya well ileliiUMl liy uinliiliiteil aiif^uiiir ridges lollowliig tlio iiicdiiiii ]i()rti<inH of tlie pliites. In iidilitimi to tlieso ridges, the snrfiieo ol'idl riidiiil MS we" us iiiterriidiiil plates is covered liy a variety of |iromi- neiicos and depress' >ns, wiiieli givo to tlio oriiamentalioii a hieroglyphic appeuraiipo.

Hiisals sluiit, slightly projecting, hexagonal in outline ; interhasal tuiture lines i: .pres.- i!. Hadials twice as wide as long, covered with three stidlate ■p'oininonc ■ , which, h'Mig c< I'lnent, f(uin a transverse ridge. First costals f|nailrnngiilar, shorte Mid nai rower than the radials, the sides ennvcx. the median ridgo cro.--. 1 iilier hy a transverse node, or liy a row of small tnher- rles transversely ncriingiMl. S . ond costals gciierally heptngonal and a little wider t' in 'he first, their .••• dian portions raised into small tuhereles. Disticha i raiiicr large, nearly as long as wi<le ; they consist in the an- terior ray of 4 X 2 plates, in the four t ;'i"f < of 2 X 2, which are followed hy 3X2 fi. <d pahnars. Anns thirty-six (exceptionally forty), two from each arm opening ; long, slightly llattened and infolding at their tips ; they arc biscrial from their bases np, niul the plates connected vertically hy wav- ing sntmi.'s. The npper horder of each nrn> plate is covered hy two or more small tubercles, which project over tlio lower end of the succeeding iilafe, giving to the surface a lile-like npponrnnce. Pinnules long, cylindrical, com- posed of about thirteen elongate joints. Interbrachials : 1, 2, 1, and one or two ailditional pieces between the i\rm bases. The first plate is considerably larger than the others, wider than high; it is covered by a central, irregu- larly stellate node, siu'ronnded by numerous small granules ; the upjicr plates elongate and similarly ornamented. Anal plate a little narrower than the ra<lials; followed by i\, .3, 2, and 2 pieces, which interlock with the inter- ambvdacral plntes above. Ventral disk depressed conical; the plates small

416

rilK CRINOIDKA CAMKRATA OF XOUIll AMKHICA.

nml liiberciiloiw ; tlie uials aiul iiidiiil iloinu idiites ii little iiioie pi'oiuiiient, but not niiieli Iiirgui' than the others. Anal tube almost ceiitial, c'oui|iara- tively narrow, and risniij but little above the tijw of the arms. Column rather stout, the joints rounded at their edges; the nodal joints (^uito prominent.

Horizon (ind J/iiu/i/^. — Keokuk group ; Crawfordsvillc, Ind. Ti//wf! in the Ii\on collection at Jefl'ersonville, Ind.

IxttnKi'l'^. — Specimens in which single arms are placed between tlio paired ones are very rare in this species. Among over forty spccinicn.s in our collection we found but two. One of them lins seventeen paired arms and one single one, the other twelve single and six paired ones. The latter specimen is so interesting that it deserves special description, and wo give an illustration of its posterior side (Plate XX.W., Fig. 5). AVlmt is most remarkable is that the arms dilTer greatly in width nnd length ; seven of the single ones are twice as strong as the three others, and one fourth longer; the latter three having the same dimensions a.s the paired ones. The arrangeuient is shown by the following formula:

PvsUrlor rm/s : 1 large, 2, 2, 2 ; — 1 small, 1 largo, 1 small, 2. Aiifiru-hdinil r(ii/.<! : 1 small, 1 large, \ large, 1 large; — 1 small, 2, 1 .small, 2.

Aiihrior rtiji : 1 large, 1 large.

It is po.s.sible that this specimen originally bad single arms, and that some of them were accidentally broken and reiilaced by paired ones.

Dizygocrinus indianensis, var. simplex W- and si. (imv. v.ir.). J'/.ifr XXXIII. Fhj. 7.

.Somewhat smaller than the typical form. In the proportions of the calyx, the ornamentalion, and in the arrangement of the plates to the top of the distichals, tiie two forms arc almost identical ; but in the form imder consideration oidy two rows of the jialmars are incorporated into the calyx, against three in the typical form; the third is a iree arm plate; the fourth, in place of being a diminutive axillary, is largo and cuneate, and suj)- por'.s but one arm. Tliere are eighteen single arms, distributed among the rays in exactly the same way as the double arms in the other. The arms have the same fde-like appearance, but are proportionally a little stouter.

Ildi-lsiin ami Luciilifi/. — Same as last. Extremely rare; we have only seen a single specimen, which is in our collection.

m

■■

;.

i

I

I ^

lUTOClUXlD.E. 417

DizygoorinuB crawfordsTillensis h. a. kiiller.*

1S91. Biilucriiiua cruirjorilsfilliiiais, S. A. Mii.i.Kii-, Ailv. Slifels 17lli Hoi- Geol, Siirv. Imliuim, p fil,

riale 10, Fif;. 11.

A ratliLT Hinall species. Dorsal cup oheouical, truncated at the base, nearly one iialf wider than liigii, the sides almost straight ; the radials and braciiials marked by well defined angular ridges, following the median line of the plate.s and proceeding to the arm bases; the intorbrachials convex, co\ered with obsciu'o radiating ridge.s.

Hasids short, extended outward and forming n small rim ; columnar con- cavity deep, occupying one half tiu; diameter of the lowi^'r face. Kadial.s considerably wider than long. First costals quadrangular, the length equal to one half their width ; tiie second pentangular, of nearly the same propor- tions as the first. Distichals two in the nntero-lateral rays, followed b\' five palmar."!, which support the arms. Tiie anterior ray has five distichals and no palmar.s ; while in the posterior ray.s the division adjoining the anal side lias two distichals and five palmars, and the o|)])osito <1ivision five distichals, making sixteen arm openings with two arms from each opening, or tiiirty-two to the species (not twenty-four, a.s stated by Miller). The arms are incurv- ing, very delicate, and .so short that when recurved tliey reach i)ut little above the summit of the disk. Regular inlerbrachials three, the first largo, the others ((uitc small. The anal inlorradius consists of six plates including the anal ; three in the first row, and two in the second. A'entral disk con- vex, as high as the dorsal cup, the plates large and tumid. Anal tube nearly central.

Horizon and Load!///. — Keokuk limestone ; near Crawfordsville, Mont- gomery Co., Ind.

7)ipe in the collection of Professor Corby.

licniarh. — This species resen\l)los Dizi/r/ocrimifi iiiiludioisit, from which it dilTers in the number of brachials, and in the more delicate and much shorter arms.

• We (jive 110 I'lRiirc of this species, ns we were unable to obUiiii the type, nnil our doseiiptimi is mode after Miller's.

S3

Vi

\\

418 TIIK CKINOIDKA CAJIKHATA OF NOKTII AMKUICA.

Dizygocrinus faoetus (>riLi.Kn and Guklev).

I'hitc XXXIII. Fiy. 12.

l^'.W. ]l,iloeriiiiis fiicfliis — Mii.i.Kit ami Cii:iii.nv; Jnurii. Cini'iii. Sue. Nal. llisl., Vul. XIII. (Authors'

cupv, |i. ;ij), ri;iti' 0, I'ij,'. 8.

C'iilyx below inediiiiii size, widor tlmn liigli ; in unininentiitiun iind gen- enil appeiinmco re.seiiiljling D. im/lanen>!is,\nil liaviiig les.s tliaii hull' I lie iiuui- l)i'r of arms. Dorsal cup seinigloboso ; tlio niilial plates marked by narrow ridges, wliieli follow the median portions of the plates. Plates convex, covered with irregular striiu and small nodes. Suture lines grooved and rather distinct.

liaso very short, circular, almost resembling a stem joint. Kadials short, nearly twice as wide as long ; the upper face concave. Fir.st costals com- paratively large, (piadrangular, as long as the radials but con.siderably nar- rower; tlieir upper and lower faces convex. Second costals a little wider but not longer than the first ; lieptagonal ; the upper faces obtusely angular. Distichals varying in niunl)cr; the anterior ray having three rows, which support the arms ; the antero-lateral ones but two. followed by two fixed palinars. in the two posterior rays, the axillary costal supports upon the side lacing the anal intrrradiiis two rows of di-lichals followed by 2 X 'J pal- niars, upon the opposite >ide three distichals. Arm foi'iiuila : 1,1. Arm bases projecting, directed obli(|Ucly u[)ward. and se]iarated iuterradially by small iutfibnichial pieces, which connect with the plates of the ventral di>k. Arms single, long, decidedly tapering until (|iiite slender at the tips; com- posed from the third joint up of two series of rather long joints. Pin- nules extremely long, stout, cylindrical, formed of ten to twelve joints, which are about four limes as long as wide. Inlerradials ; I, 2, 1, and one or two irregular pieces in the arm regions. Anal plate as large as the railials. supporting .'i. .'). L', anil 1 plate. \'entral disk depressed conical, the platis tumid and of regular size; anal tube sleiidi'r but comparatively long. conipo<ed of nearly llal pieces, among which at intervals others are interposed bearing sharp tubercles, ('(dumn round; the nodal joints with rounded, str.)ngly projecting edges.

Iltirhiiii mid Liirtil'ihi. — Keokuk group ; Canton. Ind.

IiiiiKtr/.s. — 'l'lii« species was described as having seventeen arms, which is abnormal, the regular number being sixteen. Neither has it '• eleven anal ;ilates." The authors evidently mistook the lateral ends of the arm-bearing

I

4

•«■

nATOCRINID.E.

419

brachials, wliicli arc covered with small tuborcles, for (llstinct plates. Whether any multiplication of uniis took place in this species is not known.

Dizygocrinus Whitei W. and Sp.

riatc XXXIII. Fhjs. 10a, h, uml Fij. 11.

1S31. Jiiilorrhwf jr/iiM—W. mid Si'. ; Ui'visioii ralicocr., I'lirt 11., p. lO'.l.

Sju. lliitwriiius n/u'i'i/fiiamii b. A. AllLLI^U, Ib'Jl, Adv. Shccls, l/lli iii'|i. tit'cil. Suiv. Iriiliuim, ]i. TjO, Male It), I'i^'s. 5 and d.

Calyx small, depressed globose; the dor.sd cup ccnial to, or biu little higher than, the ventral disk; the arm regions slightly projecting. Siufaco of plates ornamented. The radials and brachials have along their median lines a well delined ridge, and at each side of this ridge, toward the sides of tlie plates, an angular node, which ajjpears in the specimens as ii" forming an independent plate. Ridges or rows of small tubercles occur also on the interbrachials, some of them proceeding from the centre of the lirst plate to the radials, others to the higher interbrachials.

Basals short, forming a projecting circular rim, with a ,>ihallow striated depression for the recei)lion of the cohnnn. Radials twice as wide as long; the .sloping upper sides shorter than the corresponding lower ones. C'ostals considerably shorter and narrower than the radials; the first (luadrangular, the second pentangular. Distichals 2 X 2, of similar form, but smaller than llie costals ; in the anterior ray supporting the arms ; in the other rays followed by two rows of palmars. The upper faces of all arm-bearing plates are directed outward, and formed into circular, rather large facets with a notch at the up|ier end. The surface of those facets is slightly concave, and grooved at the inner margin. Arms eig(:leen, single, infolding, gradu- ally tapering, and constructed from the .«ocon<l free plate of two series of moderately long pieces. Pinnules very long, composed of joints three times lunger than wide. Interbrachials : 1. 2, 1, .sometinies with an iulditional narrow piece between the arms. Anal plate somewhat higher tlian the radials, and followed variously b}' 3, 3, and 2 plates or by 3, 2, and 1 ; the latter being genoriilly the case in specimens from the Keokuk group, the former in those from the Warsaw limestone. Plates of the ventral disk of nearly erpial size, all covered with a sharp central tubercle. Anal tube long, extended beyond the tips of the arms, constructed of convex plates interspersed with slightl}' nodose or spinous pieces. Column slender; com- posed of large and smaller joints, the larger ones with convex edges.

"I ^

:1 '4} 111'

V

420

THE CUINOIDEA CAMERATA OF NOUTII AMERICA.

Ilurkiin and hnnHtii. — In the Kuokuk group at IJoiio, Iiuliaua, anil at Keokuk, Iowa. Also in tlio Warsaw liuicstono at Sporyon Hill, hid., and at CJlas^ow, Barren Co., Ky., and Booiiville, Mo.

7//y)(,s in the collection of Waclisniutli and Springer.

Jiiiiiiir/,-s. — Miller'.s Jlnlorrinttn KjtinjiinHsiti wixn described from a speci- men of J)iy/</tivn'iiiis W/tllii in which tiie surface markings were eliminated by weathering. Specimens of this kind occur frequently at Spergeu Ildl, while well preserved specimens are rare.

Dizygocrinus Whitoi, var. didactylus w. ami Sp. PMe XXX V. Fiys. J J, LI

About the same size as the typical form, but the arms considerably thiinier, ami there are two arms to each opening when perfectly developed, which, however, is rarely the case. The radials and fi.xed brachials are trav- ersfd longitudinally by a strong, angidar ridge. The arms are given oil from a minute axillary in the usual way, and are .slender, long, and infolding,

//•'/■iuiii ami lAnalifi/. — Uppermost part of the Keokuk grouj) ; Hamil- ton, Ills.

7}/jiis in the collection of Waclisiuuth and Springer.

Dizygocrinus decoris (s. A. Mh-lkk).

rhile XXX V. FUj. a.

1S91, Piiforriiiii.f </--™ri. — S. A, .Mli.l.Kii; Ailv. Slicvls 17lli Uip. Cirul. Siirv Iiiiliniin, p. fil, I'InIc in, I'lirs. 7 anil "*.

Calyx of medium si/.e, a liltlf wider than high. Dorsal cup low saucer- shaped, less than half the height of the ventral disk. I'lates of the dor.sal cup li;iri'ly convex, their surfaces covered with numerous minute irregular pustules, and the radials and costals marked by small angul.ir ridges, which from the basals pass up to the arm bases. The sutures very slightly grooved.

I5;isids ipiite short, anchylo.scd. and no suture lines visible; they merely consist 01 a thickened circular rim. which projects slightly over the top of the rohunu. IJadials iind costaN verv short, both fully throe times as wide ns long. The costals support 2 < 'J distichals, and these throe row.s of palmars, of wiiich the upper supports the arms, exce])t .sometimes in tiie anterior ray. which occasicmally only has two arms given ofl' from fom* successive distichals. All distichals iincl palmars are comparatively wide and very short, the latter in contact laterally. Arm facets nearly equidistant, large.

BATOCRIXID.E.

421

•subciivular with a small notcli at tlic upper end, nnd provided with a tnms- verse, iiiiperlbrate ridge. Anns single, so far as eaii be ascertained from tho facets; tlieir structnre not known. Ivegidar interljracliials: 1, 2, 2; the first large and considerably wider than high; the upper range, wiiich sometimes consists of but one plate, arched by the palmar.s. Anal plate short, followed by seven or eight plates. Ventral disk conical, surmounted by a large, nearly central anal tube. Plates of the disk comparalivil}' large and tumid ; the orals somewhat larger and in contact ; the posterior one erect, and forming a part of the tube. Ambulacral plates represented by three sharply nodose plates of a first and second order.

Jf'irii"ii and Lacalili/. — Warsaw limestone ; Spcrgen Hill, Ind.. and Barren Co., Ky.

Ill iiKtrfiS. — This species lias its closest allinilies with D. H'A/Vi / W. and Sp., but the cup is less deep, and the tegmeii in proportion much higher.

Dizygocrinus origiDarius w, ami Sr,

J'latr XXA'/II. F,]/k h, b.

l^Sl. Kirfmnrri'iiii' orli/iiiiii-iiis — \V. and Sr. ; licvisinii I'lilircn'r,, TmiI II., \\ 171.

iSvii. ErrliiiM-riims r.(c.<(>c(V/(w — WullTlIBN ; lS8i, Cieol. Ucp. llliuoU, \ CI. VI 1., ]i. .'iOii, I'li.li- iS, fiS. 11.

A small species of the type of l)iz>/(jocniiiis Wtild. C'mIv.x biturbinate, as high as wide ; the dorsal cup a little higher than the ventral disk, with almost straight aides and broadly truncated ba.se ; arm regions projecting, and some- what indented at the iv erradial spaces. Plates slightly convex, covered with obscure granules, and the radials and brachials marked by a faint longi- tudinal ridge, which bifurcates and sends branches to tlie arms.

UmsmIs a little larger than in any of the jirecediiig species; forming a short, broadly truncated cup, with a shallow columnar depression, the sides somewhat projecting and slightly grooved at the sutures. Kadials aa lai'no as iioth costals together, wider thiiii long. First costals (luadiangular, twice us wide as long; the <ecoud a little wider and ]>entangiilar. Distichals two ov three; the iiiiterior ray has three, followed by arm plates; the antero- lateral rays two, followcil by two rows of small palmais; the ]Kisterior rays have two at one side, followed by '2X2 palmars. and at the opposite one three successive distichals. Anna sixteen, simple, stout in proportion to the small si/e of the species, rather short, and somewhat flattened at the tips; they are composed from the second plate up of two series of pieces, which

l\i f

L

• t

422 TIIK CRIXOIDKA CAMKKATA Ol' NUIMIl A.MKlUfA.

grow iiioro convex upwind. Interbrncliial.s two; the first nlmost ns liirgc ns tlie nuliuls ; the secoiul iiuicli .smaller iiiul nrcheil over by the two upper braehials. Anal plate considerably longer than therailials; followed by 3, 2, and 1 plate; the latter generally in contact with the interanibulacral piece-i. Ventral disk a little shorter than the dorsal cup, hemispherical, surmounted by a short .slender anal tube; the plates convex. Column .stout, the older joints rounded at their edges and projecting.

ll'irizoii and Liciiliti/. — Upper part of the Keokuk group at Bono and Canton, Ind. ; also in the Lower part of the "Warsaw limestone at IJoon- ville. Mo.

TuiKs in the collection of Wachsnuith and Springer.

Dizygocrinus Gurleyi (s. A. :\Iillki!). riuk XXXIV. Fig. in.

IMM. ll,it',rri„,<x ','«,7._;/i — Mai.KR; .\ilv. Sliids (mlI. Siirv. Iml. (17lli lie p.), \\ fifi, Plnlc 11, Figs. '.I aii.l III. (Not ll.il.H-riims (liirhi/i Kdwi.kv iiii.l IIaue, .\\ii;. isyi).

Of the type of Diy/f/oeriiuifi onijinnrlits W. and Sp.. and so closely reseni- liling it thiit there is much doubt if it is a good species. The specimens from JJono, described by us as •• TJi\tm(irrhiiis " Ofii/imiriiis, oidy dill'er from the IJoonville ones, which Miller ha.s relerred to Jldlorriiiiis (,'iirh>/i, in having at the regular sides three interbrachials in place of two, and .si.\ pieces in i)lace of live above the anal plate. The arms are a little longer and more slender at their tips, the angular ridges along the rays somewhat higher, and the surface markings upon the plates a little more distinct. The sides of the dorsal cup i i one of Miller's types are concave, in the other convex; while thi'v are nearly straight in the Bono specimens. Wc give a figure of one of Miller's types for comparison.

IL»h<in and Lomlllij. — Lower part of Warsaw limestone, Boonville, Mo.

2'j2)e in the collection of F. A. Sampson, Esq.

Dizygocrinus originarius, var. adultus (W. and Sp.). rintc XXXV. Figs. 14 and Jo.

1S81. Er<->i)iofi-iiiiif arlulfiii — W. nud Sr. ; Revision Paliroor., I'lirl II., p. 173.

Syii. /ltifofriiin.i Mfdiorris — ^. \. M11.1.KII; Ailv. Sluils l"ili Hep. fii'iil. Siirv, Iiul , p. fi-2, Plate

10. Fie. 9. Stii. ISiiliji-riiiii.i iuo/irillfiisis S. A. MlLLtli; ibiil., p. C5, I'latc 10, Flu'. 13.

i

I !

nATOC'uixin.T:.

•123

In the form of tlic calyx, nnanyenicnt of tho plates, miiiiber of anu opoiiings, und tlic ornamentation, iilmost ulfiitical with tho preceding form ; the specimens, however, are larger, tho arms paired and somewhat more slender. The two arms are given oil' from a diminutive axillary, whicii occu- pies the same facet with tiie proximal arm plates. Occasionally one or more of the arms are .single, and in a very interesting specimen of D. oriijin'irinH (typical form), whieii had evidently lost two of its single arms dm'ing life, these were replaced hy two pairs, wiiich are developed to oidy one hall' the length of the others.

J/iiri:iiH iiiitl Ldialili/. — I'pper part of Keokuk group at Bonn. T.awrcnce Co., Ind., and in the lower part of the Warsaw limestone at Boonville, JIo.

Ti/pcti in tho collection of Wachsmuth and Springer.

Jt'i iin(rl,s. — In the sjiecimens which Miller described imder ItHlncriiiiirt liiiiiiirillriisi.i an<l 11. iiicdiiKri.i, the doid)le arm structure is only partly develoi)ed ; some of tho arms being single, others paired. The modifications thereby prodiicoil in the arm formula probably led Miller to regard them as speeilically distinct.

Dizygocrinus cantonensis w. and Sp. (nov. sikt.).

r/<i/c xxx//r. Fi.js. s,i. h.

Calyx depressed ; the dor.sal cup ver}- .>-hort, rapidly and nniforndy spreading to the bases of the free arms; its sides straight or .slightly convex, the plates Hat and apparently without ornamentation.

liMsals short and narrow, forming a circidar ridge aromid tho colunm. Padials com|)arativi'ly small, once and a half as wide as long. First costals a little narrower than the radials, twice as wide as long, rpiadrangular. tbeir lateral faces convex. Second costals ])entangular, somewhat wider 'u! longer than the (irst. That of the anterior ray supports two rows of two distichals, whicli are as large as the radials and support tlie arms. Tho costals of tlu' four other rays have at one side an axillary distichal, followed by 2 X - pahuars, at the other two large distichals, thus making the arm fornuila 3, 3, 2. Tho arm-bearing plates support at their upper facet a small trigonal axillary, and at each side of it an arm plate. Arms far a])art. paired, rather long, incurving, roimded in the lower portions, but distinctly llaltened and almost twice as wide in tho upper. Pimudes rather stoui and long. Interbrachials four to live, joining the interambulacral pieces ; the anal

^i

{

s

i?

TlIK CRIXninK.V CAMKRATA OK XOUTII AMKRUA.

iiiterrii ^ < ists of 1.3, 2, nnd 2 platos. Tlio ventral disk in hidden by tiie ai'tii our speciineiis. Anal tube coinpoMod o{ Hat pieces; it i^

vatiier hU and lonj,', reaching to nearly an inch beyonil tiie tips of the arms, and evidently was still longer. Column snuill, composed of thicker and thinner joints with roinuied edges.

Ilnri-.iiii (iiiil l.iiriiViti/. — Keokuk group, Canton and Edwardsville, Ind.

7//y/(.«( in the eollection of Waclisnuith and Sjiringer.

Ill iiiiirl.s. — This species has its closest athnilies with the preceding form, but is readily distinguished by it.i larger Hi/e, the more abrupt spreading of the dorsal cup, the greater length of the anal tube, its spatulate arms, and by having fourteen pairs of arin.s instead of sixteen.

Dizygocrinus unionensis (WCiitiiix). Plole XXX V. Fi'i/x. m, J7, JS, JO, 20.

l'*'<t. Ihilni-i-iiiin «///(///(■//</.< — Willi rilt;N ; Itiill. II. (if llliiinis Sliili- jriisniin. p. iCt.

I'-W. J!iilui'i-iiitt.< iiiiioiirii.iin — \Viiliriii:x ; (iciil. |{r|i. Illiiiiii-, Viil, VIII, |i. v|, rialc 12, Fi(.'*. 5, 3.;, mill I'l.ilc l.'t, Kiu'. :i. S^Vii. /Iiifurriiiii.^ /iii/r/i,'//,is — S. A. Mil.l.lli; IS'.ll. Adv. S^lircl^ 17lli ('n"\. l{i'|i. Iiiiliiiiiii, p. I','*, I'blc

II, I•■i^'s. 1,1 im.l H. Svii. IliltifrliiM Diirisi — UinrT.rv unci IIaHF. ; l*-!)!, Kiin«ii' Cilj- SriiiilisI, p. 110, I'liilr li, VIl'. 9. Sii. (:) Ai-diiocriiiiis O/z-iy/i — Hall. ISfil), Siippl. (jcul. 1! p. lown, p. 6t.

Of moderate size. Calyx depressed ; the dorsal cup shorter than the ventral disk, almost saucer-shaped ; the nppor brachials placed nearly at right angles to the axis of the calyx. Plates slightly convex, covered with oljscurc granules, the median portion.s of the radials and costals marked by .small transversely arranged nodes, which arc confluent and form ridges. Sutnre lines more or less grooved.

Basals short, annular, slightly projecting bcj'ond the column. Kadials twice or three times as wide as long, their upper f.ices concave. Costids as long as the radials but narrower ; the hrst (|uadrangular, the second pentan- gular or hcptangular. Distichals 2x2, followed by two rows of ])ahnars, except in the anterior ray which has three successive distichals. Pal- mars and disticlials of similar form, and as large as the costals. Arms single, generally eighteen, arranged at ecjual distances around thccal3x; of moderate length, rounded on the back, and biserial from the second free plate. The two proximal arm jdates quadrangular, somewhat wedge- shaped, and as large as the first palinars. Pinnules stout ; their joints

I

•f^

UATOCBlNIDiE.

425

twice as long ns wide. Intcrbrnchials two or tlirco on tlio regular .siilcs, tliroo to six on the posterior; nrched by tiio piilnmrs. Anal plalo a little liiglier than the radialM, occasionally I'oUowoil by two plates in the second range in place of three ; the second anal, although present, not in contact with the first. Ventral disk highly convex, slightly conical, the plates nodose and of irregular arrangement. Anal tube slentler, almost central. Cohinin thin ; composed of larger nnd smaller joints.

llinizon und Lumlili/. — War.saw limestone, near Iluntsville, Ala., Tate- ville, Pulaski Co., Ky., Boonville, Mo., and Lee Co., Va.

The tyiie speeimei , which is from Union Co., Ills., is in the (Worthen) Illinois State lollection.

liiiititr/c.i. — Tiiis species is very interesting ns having sometimes in the posterior interradius but two plates above the anal piece, in which it shows a tendency toward the Actinocriniihe. It also has a wide geographical range, and mil}' be regarded as one of the leading forms of the lower part of the Warsaw limestone, but occurs already in the Upper Keokuk beds.

ArtiwirriiiiDi Corii/i Hall is very possibly identical with this specii s, but the type in the Illinois State collection at Springfield is too imperfect for accurate definition.

DizygoorinuB unionensis, v.ir. divalis (S. A. Mimkh). P/ate XXXV. Figs. 21, 22, 23, 24-

1S03. Biiloeriiiio dinitis — S. A. MiLLeii; Adv. Sheets ISlh liip. Ocol. Siirv. llibsouri, p. 22, Tliitc III., Fi;."*. li iiiul 7.

A little larger than the typical form ; the dorsal cup more expanded, the ventral disk somew hat more conical, but so clo.sely resembling it in its general habitus, in the form and arrangement of the plates and their ornamentation, that the two cannot be distinguished nnless the arms are preserved. Arms double from their origin, thirt^'-six in fully developed specimens, rather stout and densely crowded. Arm joints of more than medium length. At the four regular sides, the intorbrachials consist of three to four pieces, at the anal side of from six to eight.

Horizon ami LvcalUy. — Associated with the preceding form at Boonville, Mo., and at Iluntsville, Ala.

'j.ypes in the collection of Mr. S. A. Miller.

Remarks. — That we have here a mere variety of Dizyfjocrinus umonciisis,

yi U

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W

■v^

MM

mm

426

TIIK (iUXOIDKA CAMKUATA OF NUIMII AMKIMCA.

ami not a distinct Hpcciou, is clearly sliown by the fm-t that one of our fpcci- nirns lius but a wiii^'le iiaiiod arm; in another all the arnw are paired except one, and tiiat \vc find all variations between these extremes.

(■') Dizygocrinus Gorbyi s. A. Mimkh.

H91. liiihu-rinini Cor/jyi — S. A. Milieu i Ail. Sliirts 17th 1((|>. Cunl. Surv. Indiaim, p 63, Tlntc 10,

KiK. 10.

Of medium Av.o. Calyx globo.se, height and width a.s eight to eleven ; the arm bases projecting, the and)ulacral openings direcUd npwards. Sur- face of plates convex, the radiais and brachials transversidy angular; the suture lines beveled.

llasals formiiij: a hexagonal disk, two thirds wider than the diameter of till' column, the plates upright, exposing a height about ecpial to the distance from the colwnni to the upper margin. Kadials very little longer than wide, the upper face slightly arcuate. First cosfals rpiatlrangular, about one fourth wider than long; the second wider and longer than the first, two of them pentangular, the others hexangnlar. Disticlials 2 X 10, gener- ally wider than long, the upper ones larger; nine of them bear a palmar; the one of the anterior ray siijiporting directly an arm. Arms nineteen, simple, long, rounded on the back. Pinnules composed of ten to twelve Imig joints. Regular interbrachial.'* three; the first large, nine-sided ; the two upper smaller. Anal side composed of nine plates; the onal plate the largest of the eup; followed by .1. 3. and 2 plates, which decrease in .'*i/o npward. Ventral disk conoidal, covered with convex plates. Anal tube almost central, .small, cylindrical ; composed of rather large, slightly convex plates. Column round, of medium .«ize.

Jl'r!.~'iH (iml Liicullli/. — Lower part of the Warsaw limestone ; Boon- ville, .Mo.

Tiijif in the collection of Prof. S. S. Gorby at Indianapolis.

l{iii((irl;s. — This .«pecie8 needs to be compared with the t^'po, as Miller's description, from which we give an extract above, docs not agree with lii.'J figure. This is especially the case with regard to the proportions of the ba.sals, radiais, and costals. The "upright" basals are not seen at all in the figure; the r.adials. and costal.s, which wore said to bo but very little wider than long, appear extremely .short, the disticlials are nnusually large, and are followed by two palmars in the calyx, not by one as described.

m

IlATOt'HIXID.K.

427

^

DiaygoorinuB biturbinatus (IIai.i). PMe XXXI II. Fiij. 0.

1S5S. .I'llHo.-niiiii ii/iidiMlin—\l\u.; licol. Ilcii, hi»a, Vul, I , I'ail II , p. Clft, pliili^ Irt, Fi(?s. 5 njicl

(W, //, I'. 1H73. lldhrriiiHf hihi:l,iiiiiliit — Mkkk nnil Wmutiikm; (Ivol, Itcp, llliiKiiH, Vol. v., y. 'Mu. 18S1, //(//wrM«< '///i(/7///ii//«i — W iukI Si'. ; llcvcsiiiii I'liliicici Tart 11, p. Klj.

Bjfii. lluluffiHiii l^iiiiuHii) Mii.Ltu iind (ji ULKV) l^UI ; lnol. Siirv, llliiiuii>, Hull. 3, p. 18, Plate 3, Fiffn. \ mill j.

Ciilyx bitiirliinuto, nl)uiit ns wiilu nn liigli, tliu vontral disk mm high hh thu dorsal eiip. I'lati's hi'lovv tlie aiiii rt'>(ion.s Hut, alwvo uliylill}' toiivux, thfir siii't'aco pi'ifeutiy smootii ; sutiiro iiiius inilistiiift,

Basals small, Ibrmiiijf a lie.xaiixnlar. shallow hasin, with a .-lightly pro- juetiii^ rim at tlu'ir lo\Ner margins. Hailials oiu'c and a hall' as wide as long, thu upper facu straight. First costals quadrangular, co isideralily narrower and shorter than the radials; the second a litll j longer than the llrsl and pentangular, their sloping n|)per fai'cs at ri^lit angles. Distirhals three ill the anterior ray, two oidy in the antero-lateral ones. In the po'^lerior rays, the divisions next to the anal interradius have two distichals, the others throe. All division.s with two distiehal.s are followed hy 2 X 13 palmars, thoso having three directly by free arm plates. Arms si.xleeii (exceptionally .seven- teen, there being sometimes an additional one in the anterior ray ) ; simple, slender, pointed nt their ends, and incurving; they are biscrial from tho second free plate, and provided with slender, long-jointed pinnides. Inter- radial s|)aces slightly depressed at the ar:n regions, licgular interbrachials three to four; the fust very large, as wide as high. The anal interradiuf. contains from seven to nine pieces, the anal jdafe being succeeded by three plates, nnd these l)y three and two; occasionally there is another small plate above, separating the palmars, and a similar plate sometimes occurs at the other sides. Ventral disk subconical. and extended into a central anal tube. The plates are but slightly convex and of almo-^t uniform size, except that the posterior oral is twice as large as any of the four others. Column decidedly tapering; the joints nearest the calyx nearly twice as wide a.s those two inches farther down, the former with convex edges, the others almost cylindrical, and there are six joints to the last internode that is pre- .sorved in the specimen.

Horizon ami L<'CiiIiti/. — Keokuk group, near Keokuk, Town.

Ti/2)cs in the (Wortiien) Illinois State collection, Springfield.

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hi

428

Tin: CULNUIDKA C'VMKK.VTA Ol' M>!ril A.MhlilC.V.

Itcmiiikt. — Piofi'Mfioi' Hall iIchcHIjoiI llii- h, i' •■ j m Jiiiviii|^ Init Svo pliilcn above llie una! \\Wvv, uliioh in curtuinly iiljuon."::! '..i war Biiociiuciiu clondy Amw tlio pruHuiico ul' tlii'fu (iluti'!).

DlzygocrlniiB montgotneryonais Wortukv. Plata XXX/ll. Fi'ju. ,i, and 4, and I'latr XL 17. F!;/. JO.

ISSl. y/.i/" vi««< wf«/yOT/i-/t'.//.(t — M'oitTiiKS 1 Hull, ii, Illiiiiiin Sliilc Mus. Xiil. Hut., p. 35, kiitl Ot'ol. Hr|., Illilini'*. Vnl. VIII , |i. i:l, riair \i. I'il.'«. i. Sir/. Svii. Ii'ln,',i,iii» Oiifh'ii ~ lliiHiKV iiii.l ll\ut (lint S. .\. Millt'i), I'^Ol, Kniiin* CIt; Scifiit,, Vul.

v., p. 113, 1'l.iti. ;i, Kiir. 7. 8vii. /(,(/.../('«»i Sifi-rti— l(ij«i KV iiijil lIuiB, l'<ill, iliiil., |i. lin, riiitr :), Fijr S.

f'alvx of nu'ditiiii sizi'. Dorsal cup KiiiUH'r-.xhapfd, lower lium tlie vt'ii- tral ili.>'k. roimdcil at the Hides; tlio arm-la'iirin^,' plates piodiieed (tiitwanl in loiin (>r looililike i>roJeetioii« around the calyx. I'liites from perfuell}' Hat to slightly elevated, anil without ornatiieiitation.

Basiils .small and short. I'ormiiijr a liasin-shaped depre.ssion, which is com- pletely (illed liy the upper stem Joint. Hadiids twice as wide as lonj.', the upper face concave. First coslals a little shorter and coiisiileriildy narrower than the radials; the second slijr|illy lonf;er ami somewhat wider. Distichals. ns a rule, loiijrer than the costiils. They coinist in the anterior ray of two series of lour plates, whitdi sti|)port the arms, the aniei'o lateral rays have 2x2 distichals followed l>y three successivi' palmars in the calyx ; while the two posterior riiys in one ilivisioii have four distichals ami no piilmars. in the other — that adjoining,' the anal interrtulius — two distichals tmil three pal- mars. The brachials of the two upper rows project outward, anil are roiiniled and grooved laterally at the suture lines. Arm opeuinjrs sixteen, the interspaces between the rays sli<;htly widest ; the nrm facet semi-circular, and directed obliipiely upward. Arms in pairs, given olT in the usuid wiiy ; they are long, very slender, tapering, and somewhat angular on the back ; the joints of medium height, ami their upper tmu'giiis projecting over the lower ones of succeeding pieces. Piniudes long. Anal pl.tle not quite as wide as the radials but higher, and followed by eight to nine iuterbrntdiiids, against three or four at the other sides, those of the anal side being alwitys, and those of the rcgtdar sides .soinetimos. connected with the plates of the disk. Ventral disk tumid, the centre of the plates covered with a very small tubercle. Anal tube slender, the plates smooth or slightly convex. Column

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IIATCKUINID.i;.

4:21)

tt^

I

rittlier liirgu fur tlit> xpucicM, tliu nudal joiitt.s projecting niul romiduit at tli> I'dgcf).

Jl'iflv'in mill Liii'iil'il;!. — U|)|K'r piirl of Koukiik gioiip, t'ruwl'ord^villc. Iiiil., Keokuk, Iowa, uml I'ike L'u., Mo.

7'7/<f ill tiie Illinois Sdite eolleetion, Siiriiigliflil. (The npeeiiiicn figureil on I'lalo XliVI. is tin; \\\h' of •• IhUmrinus (Jurlnji" 1! iiih! II.).

Dizygocriniu montgomeryoDBis, v n. unibrachlatuB W, aii<i kc, (mov, var.).

/'/,(/, XXXIII. Fiijs. .;. ii. h, r.

Till) iiliove imiiie is proposed lor a Ibrin veiv similar to I), iiiiiiil'/iniii ri/nixis, liiif having ningle arms in phino of donldc ones. It also clostdy ri'seiiilik'M I). Iilhirhiiiithin ; liiit the spepimeiiH are linger, the dorsal enp is pioporlinnally shorter, till! arms are loiijrer, less tapering, and placed liirlher apart.

Ilni.iiii mill ///«■'//////. — As.soeiated with I), ni'ni/ij'iiin n/uisl.i in tho L'pper Keokuk lieds, iriir Kenkiik, Iowa.

T'//iin in the eolleelioii of Fiishon A. Cox. and \Vacli.sniiitli and Springer.

DizygocrinuB mutabilis w. ami si. (n.iv. nyw.y Phi,' XXX r. Fiij^. S, !>. 10, II.

Calyx hitiirhinnto to siihglohose ; the dorsal cup a little higher than the ventral disk ; the plates of the lornuT Hat, and the siirfaee without ornamen- tation or other iiiarkiiigs ; suture lines slightly grooved.

Hasals rorining a low hasin. hexangular in outline. Itadials fully twice as largo as hotli rostals together ; the upper face concave. First costals very nliort, linear, the sides convex ; the second pentangular villi obtn.so ujipcr angle. Dislielials larger than the costals, increa.sing in width upward. They are represented hy two ranges of three plates in the anterior ray, and also in one of the divisions in the other four rays; while in the opposite division the second piece is axillary, and supports 2 X 'J pnlmars. thus giving rise to fourteen arm openings, which hear either single or doiilile arms. Among our seven specimens there is hut one in whicdi all the arms are paired. In the six others the paireil arms are indiscriminately intermingled with single ones, and in three of these specimens the right anterrvlaferal ray consists uf two pairs, of wliicli one pair rests over the suture line of two adjoining jml- mars and not upon a distichal, Arms rounded, long, incurving, and com- posed of rather long transverse pieces. Pinnules Hat at the surface, their joints rather short, llegidar interhracliials three. The anal plate is consid-

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TIIK C KINOIDKA t'A.MKKAT.V OF XOlMIl AMKKKA.

oral)ly liiylier lliiiii tlie nuliiils, ami Minporls .'5, 'J, niul I iilali-, llic latter ivsliiig l)etwi.'c'ii till' ann-lieariiij^ palmar.s. l'lal^'^^ of llu" ti'j^miii iiodosi' ami of imil'oi'iii fize ; the anal tube ratiier stont, ami foiii|io>e(l of slij^lillv convex pieces, wliich at intervals iire inlers|)ei'se(l with tiibeieulons pieces, ('oiuuin ilecieasing in size downwanl, the joints iony,

IIiin.V'11 (iicl L'^id/ity. — Keokuk group ; Indian '.-leek, Montgoinerv Co., Ind.

T//JX'' in ilio collection of Wachsmuth and .Spiinger.

lioiini/cs, — This species reseinl>les JJi'.i/i/nrriiiii.s hiliirhiiniliis Hall, ficnn which it diliv IS in the arm foiniuhi. Specimens in which llie arms all aie single liave not as yet been discovoi'ed.

Dizygocrinus ouconua (Mki-k .ami Whiiiimn). riiilc XXXV. Fi.js. 7<i. h.

Til'.j. .l-H,i,.^n„i'< {.lll..i„;,s,il!n,-riiia') ,i(r„uil!i—\\. liuil \\ \ I'miv.il. .\c:ul. N;il. Sii. riiilii., p. Irtl.

\^i''l. lliltn-iillHS (_.l//':/lf,fill/n,;-iuil.') rll,-i,/lilf — M. Mu\ W , ; ticni. l(r|i. jlllll'ils, Vlll. V., |i. IKW.

l"''-!. ilil'irriiiin ein'uiiiit — \V. ami Si'. 1 l(i'vi>iipn I'lilii'cicr., I'nrl II , p. Mill.

Svn. /.'//.„vi«/«..«/„v.«/.v«— Wi.iiriii.N ; (Itul. !tf|> llliii..i>, \„l, VIII,, p VI, |'|,.,i,. 1.1, Kii-s i,,,,,! i^.

In gener.il lorm resembling .\l/"iir'ixiiH<'i'riiiiix. Dois.al cup mmv slightly ciiuves. the sidt's spreailiiig alinipll^- from the top of the basals to the arms. Base .small, projecting, circular in oi'tline. with a shallow depression for the reception of the column. Surface of jdales smooth, without ridges or other elevations. Suture lines indistinct. Ivadials hexagonal, aliout twice as wide as higli. First costals ipiadrangnlar, smaller than the second. Distichalu two. I'oliowed in the two antL'ro-lateral rays by two rows of two iialmars. ami four single irms; while the anterior ray. which has an additional distichal at each side, and no palmars. lias two arms. The posterior rays lia\e imlmars ill thedi\i>ion ne\t to the anal >iile and three arms, there being sixteen arms to the species. Slrucliire of the arms unknown. Iiiterliiacliials iluee at the iigular sides, and six above the anal plate, the upper row at all sides aiclnd by llie ariii-beari-ig lirachials. Ventral di-^k regularly conical, twice as high as llie dorsal cup, composed of rather large, slightly convex pieces; the pos- terior oral erect, and forming the base of the anal tiilie. The tube stout at tlie base iinJ u'-'arly central.

U«n:iiii iukI Lifiil'ili/, — Warsaw limestone ; Spergen Iliil. Ind.. I'nion (.'o . UN,, and Taylor Co.. Ky.

////" in the Illinois State collection, Springfield.

4-.

IJATOCUIXIDJ'..

431

lii'mnrls. — Meek and Worllicn in ISGo (Proceed. Acad. Nat. Sci. Pliila., p. IGi), intiinateil tliat probalily this Hpecies was genericnily. nnd perliaps speeilically, identical witii AZ/'ijifusfi/ZoiriiiKs roiiiciis ; but ncitlier the one nor tlie other is tiie case. Tiiat ,-pecies has twelve arms, and tiiese obviously were given olT from tlie cnlyx in a very similar manner as tlio arms of .\;/(irii'iicri'iiii.f ; wiiile tlioso of ]H:i/(jiicriiii>s (iirnuKx, to judge from tiie size of the arm facets, were (piite slender at their bases.

.1*

4"

Dizygocrinus euconus var. abscissus (Kowi.kv and llviti). Plate XLVf. Fnj.t).

I»91. llifwi-iiiiit iilisnu'in — UoMI.HV anil II ilit: ; Kaiivis (,'il>- t>cinit., ]i. 115, I'latn .'!. Tii;. It.

Svii. Iliil<a'ii,iu.i rriiii'hif S. A. Mll.l.Ku; Ailv. Shirls lilli Kc|i. (iiiil. iS'irv. Iinliaii.'i, l>iUl, p. fi7, I'liilc II, Kitjs. 11 Mii.l \i.

This form agrees es>enlially with the jn-cceding one. Tt is, however, somewhat larger, lias twice tlu' number of arms, and the third palmars arc incorporated into the cnlyx, while they are free in the other. There are tiiirty-two arms in the normal state, «hich are rather short and slender, and decrease in si/e upwards. The arm plates are short. A'entral disk decidedly conical, the plates slightly convex.

Iforami ami hicalll;/. — l'p[)i'r part of the Keokuk gi'oup. and lower part of the Warsaw limestone ; Taylor Co., Ky.. and at ISoonville and L'uiry- ville, Mo.

7//y/i in the collection of Mr. \\. R. Rowley, Fort Smith. Ark.

liiiiiiirh!<. — Rowley and Hare's name Jiiitmrinm alitnusfiin was published n month in advance of Miller's //. raiiintiis.

I IVI

Dizygocrinus rotundus (Vwd. ami Sm m). i '/<(/( XX JX. Fiij'*. oa-r/, (Dill 4-

ism. ./<'/mi,,w///'.< — ClirUtv's liili'r>4 nil C'nluijy ; I'lalf 1, l''ii:s. H , -11111 t.

I'i.'ij. .{'■liiiiirriiinx r.</«»(/«,t -- VisiiKI.l. .■iiul IniI'M. ; (iiul. I(('|>. .\li--iiuii hv Sniiilnw, Piirt 11., |i. 101,

I'hili' A, KiRs ill, 6. l^r;!. Ilif'icriiiHH riiliiii'lH^ — Mh:k :mA WuUTiiKN ; (icnl. Idp. llliniii«, Vnl, V , p. .'iil7. 1->>1. Iiit:rriiiiii riifiiii'hit—W. anil Siv ; llrvi~i.iii riilavicr., Part II., p. |lis.

!<vii. .l,'H/inrriiii4.< <iU,i/ii.i IIai.i ; |M"iii, Siippl. (ii'ul. lii-p. l.iwa, p. '.\S.

Smi. IU,i,-riiiHK M,i/iiii~ Wimiltl.u; Mciu. Aimr. .\lus. Nat. Ili^l , l^l^'t, Vnl. I , p. \i, VhW I,

Form of calyx varying from ovate to depressed globose. Plates flat, the surface perfectly smooth, and tl' suture lines indistinct.

Ilasals small, forming a saucer-shajied disk, hexagonal in outline, slightly

exciiViUed at the bottom. First costals twice their width, much narrower

«r

'M

1 \'

%

ih

mm

^^^^^

432 TIIK CKIXOIUKA CAMKHATA OF yoKVll AMERICA.

than the railials ; (juaih'angiihir. Secoiul cof^tals a little larger; Irregularly pentangular. Distlchal.s in two rows, the upper wider and obtusely axillary. I'alniara two, the plates of the upper row snuillest, constituting (jiiile fre- (luently a part of the free anus. Arm ojienings (ihu'eil at eiiual distances, except tile two I'auing the anal interiadius, which are souiewhat farther apart. Arms normally twenty, but varying from eighteen to twenty-two ; rather short, slightly llattent'd at the tips. Interbrachials from three to five, in two or three rows; those of the second row varying in height. The nnal inler- radius gciR-raily has lour ranges; 3. 3, 3, 2, arched over by the pahnars. W'Mtral disk a little shorter than the dorsal cup, hemispherical ; the plates rather large and of nearly imiform size. Anal tube subcentral and com- paratively short.

Jfiifir.'Mi and Lura/lt//. — Upper Burlington limestone; Ijurliugton. Iowa, Ilender.son Co., Ills., Palmyra, Mo., and at all localities where rocks of that fmiiiation are oxpo.sed, tiiis species being one of its most abundant and characteristic lossil.s.

7u//('(/•/.^■. — J)i:i/t/i>rriiiHS riilniiiJiis is the most connuon species of the l^urlington group; it occurs uujst al)undaully in the white crystalline layers of tiie middle part. The number of arm-^ is ([uite variable, wo liave .«|ieci- mens with 18, 10, 20. '21, atid 22 arm ojienings. 1"he arms, which are rarely preserved in this species, ar: simple, there being but one arm to each open- ing ill all our specimens except one, which has a single paired arm in one of its rays.

ll.iH's •• Ar/liiocriiiiiti" iihladis is a depressed D!^i/i/"criiii(S ri'/inuhis with tweiil\-two ariu.s.

..

«'r.

Dizygocrimis dodecadactylus (>rKKK ami Woiitim-n). FMr XX JX. Fli/s. 1,1, h, c.

l-'iil. .l,-/i,i:,r,-i,iiis 'h.hi-nihirfi/li).' — .\Ifi:k (iikI W ; Prciowt. Aofiil. N:it. Sri Pliil.'i , p. IHI.

I'-r.ri. Ji'liii,iiriiiin{llal'.,-,iiiiis)ili,ilmitl,irlj/lii!<—'S\.nw\\\.\ dc"!. Kep. Illiii(ii>, Viil. II , p i?0."i, Tbte

13, Figs, 'ill, h. c. l^r.'t. Itiiliii-ri,iiix ili,il,f(iil,ii-/'ih(» — Mkkk mill WimTiifx; iliiil.. Vnl. V., p. liOs, 1^^I. ll,ih,'riiia.< •Iwl.vinlinli/hn — W. and Sr. ; Hovisi.iii I'lilirorr., I'nrI II , p. Ififi.

Probably an early jihaso of Dhi/f/ocrhiiis rotuwhix in a persistent form. It is a ciMsiderably smaller species, and has twelve instead of twenty arms. Calyx globular, the ventral di.sk as high as the dorsal cup. Plates smooth, suture lines moderately distinct.

Paso .>ihort, rounded, excavated at the bottom. Radials laige, wider th.in long. Costal.s small, tw'ice as wide as long, the upper oi. ; axillary, aipport-

M'

A.

%ft>

nATOCniXID.K.

433

iiig a single row of largo ilisticlids, nnd tiiese tlifi froj nrms, except in the posterior rays, in which the plates facing tlie anal side are axilliiry, and give olT two arms, or three to tliose rays. Arms <lt'licate ; composed of two rows of rather long joints alternately arranged. Anal ]>late a little hjngcr than wide, contrary to the radials, which are wider than long; it is followeil iiy three and one i)late. Thu other interradii have hut one interhriichial. ahuve which the distichals meet. Ventral disiv highly convex, composed of hut few large plates, of whicli the orals occupy almost one half of the wiiole sm'face. Thry are surrounded hy live large I'adial plates, hetween wliieh are interposed two »r three smaller interamhulacral pieces. Anal tuhe nearly central, very thin and short.

Iliirirjin iinil J^dik/I/i/. — r|)per Burlington limestone ; Builington. Iowa.

T//jir in the Illinois State collection.

Dizygoorinus andrewsianus (M( Chksxkv). J'/<(f,' XX fX. ri</s. J„. h. r, ,1.

ISfiO. Ai-liiiorriniit aiiih''irs!ii,iiis — M(riiisNi;v; Niw P,-ilii'uz. fuss., p 27. Isii7. Aeliii'ii-riiiiit (iii'Irrir'iKiiii'i — M( CiiKsSKT i Cliitviiid .\c.iil. Niil. Sci., |i. iO, Phitr .'i, I'ii; 5. l^Sl. lldtwi-iiiin iiiii/rriruiiiii/.< — \V. iind Si'.; I(('\isi<jji IViluiicr., I'liit II., |i. li'p.'i (rrncrid .\c:iil. N;it S<-i. I'll:!!!., |). WJI.

A small species. Calyx ohconical below the arms, the plates snu)oth and almost Hal ; ahove the arms conicid. and the plates convex. .~omelimes tuherculous.

I?as;d cup low saucer-shaped, the sides not jirojectiiig ; the colunin facet small, interhasal sutures inilistinct. Hadials of niedinm size, wiiler than long. First costals small, quadrangular; the second generally he]itani:ular. a little wider than the (Irst, hut not (juite as long. Distichals two in all the r.ays : hut in four of them the n])per is axillary, and followed hy a row of ]ialmiirs. In the anteri(M' ra\', in which tliere are no palmars. th(> disticiials are some- what larger, and the socoml su]ipor*s the arms. Arm-hearing plates slightly projecting, ill contact laterally except at the anal side. Arm o])i'nings directed oiilwai'il. Arms long, infolding, rather thin, not touching each other laterally : they are sulicylindrical at their bases, souu'what llatteueil anil widi-r at the top. The anal plate, which i- as large ns the radials ami of a similar form, is followed liy rows of ,T, .". and 2 plates, sonu'times with an additional piece in the arm regions. The interbrachials of the four other .fides consist of four plates in three rows. The jilates of the ventral disk are moderately large and of nearly the .«aine si/e ; the anal tube is .snb- central, rather thin an<I short, not extending beyond the tips of the arms.

'. ; i

%

MWM

434

THK CIUXOIDKA CAMKUAT.V OK XOKTII AMKIMCA.

Ilorlr.iin awl Linilllij. — Upper llmliiigton limestone ; IJurlingtoii. Iowa.

JiaiiiifLi. — This species wiis ilesciibeil by McCliesiiey as liaviiig i)iil t'oiir plates ill the anal intenailiiis, and three at tlie other sides. In tliat case the type specinien was a very yoiii);,'' example, in whieii the up|ifr plates hetween the ray.-) were as yet undevelojied.

LOBOCRINUS W. and fip. (n.iv. gpi,.). (.\"/Jus a lul'i' ; K/ji'ior, .1 lily.)

Form of the caly.v from ]iyrit'orni to wheel-sliapcd ; the rnys inore or les-f (Mstinctiy loheil. and the arms arranged in groups; the ventral disk high, conical or liiilging. I'lates convex, Kinooth, or ornamented, liasals tiiree. rather large, forming a snitcylindrical cup, wiiicii is thickeneil at th<' lower end. Hadials larger than iioth costals togetiier; the second coslals iVei|iientIy smaller than tiio lirst. Arm I'acet.s siihcircidar, concave, and in some species provideil with a transverse imperforate ridge. Arm oixMiings large, directed iip'ward. There are no trai'i's oi' respiratory pori's, lint they may have been located close to the etiges of the amlmlacral openings, some of which are a little excavated at one Hide. Arms one t(t each opening; short, cylindrical, and biserial from the base up. I'innules long. Inter- brjchi.ds nnmerons, ami in cnnlact with the inteiambid.icrals. ."^onie species have interdistiehals. Anal plate sncceeded by two intcibrachials with a sec- ond anal between them, and two or three additional rows of frmn two to tlin/e pieces. The ventral disk is generally large, the anal tid)e centr;\l, stout and ver}' haig. Orals well delliU'd. being larger and more nodo-e than the ■surrounding plates, e~]i('cially the ))(>slerior one, which is erect, and forms the base uf the anal tidie at the anterior side of the teginen. The radial dome plates are large and ipiite prominent. Column stout, round, and coin- p:iraiivcly long; ;i.\ial canal small and ]icnfangnlar.

J)i-<iri/iii/''iii. — Lnliucrldii^, so far .as known, occnrs tinly in America, and is resiiicted to the nurlington and Ki'okuk groups.

'I'lifii' of the genus: hi/incriiin.i Xiis/ii-i//,i> (Troost).

H, iiiiii-hs. — M()<t species (if this genus were origimtll}' described nn<ler Ai'/iii"i'riiiu.<, but were afterwards refcrrcMl by Meek and Wort hen to Jtii/n- rrimi-1, aivl one of them to r/nrdri'iiinn. U'lie latter mime had been |)rop().sed n.'f a subgenus of Arlliwrriiim with " Ar/ihnrriniis {fjii'riirrinti.-i] fii/n/nniiix" ns typo, ]^y placing these .species nnder Jli/'icruini', we slioidd have to ignore the principal character npun whicb. that genus was founded. I'm in ali <(

I I

HATUCniXID.T:.

4 .'Jo

tliL'iii tlie inteilH'uuliinls aiu coiitiiiiioiis with (Iio ititcrninbiil'U'ral pliitos. Ayaiii BtUiivrinus liiis woll dcliiicd, laiyo ivspinitory pores, wliicli aie ap- parently iimei)res(.'iitod in /^'■b^rtiiiim.

Lobocriaua Nashvillae (Tiihost). J'/<iic XXX/. Fi./. 1.

ISiy. Ai'tiini<'riinii Xtuffirill'f — Tuuij.sr; (,';U;tl. of L'liiiniilcu (I'mcut'il. Aiiicr. Assop fur Atlv Sci , \^V.\

V ''■"). ISJS. ./.7/«..,v,««. A'//./ir,7/,p— Hull; (in,l. li,|.. l.iwa, Vol, I., I'.-.rl II., |i. OiW, I'hili' 15, li^'. 1, .tinl

I'l.itc! Hi. V\'i-. y. I,. 1S7:1. /I il,„;;;„a \„.</in//,r— M. ,'ill(l W. ; fl.-<il. U,.|). lllill.iiH, V.,1. V , |i. lir.S. ISSl. Iliil'ifriiiiit ,\',i}i/iri//,r — W. uiiil Sr.; Ki'\isiiju I'iiIii'mci., I'.irt II., p HiT (rnircnl. Aciul Niil. Sci.

riiilu., p. :iU).

I'S.'l. .l,-li,l;,-,i,lii» A'./>//n7/,f — (JlKNSTKIir ; ll.Cliilll. llll- r. llif:irll'llklMI(lc. I'lalc 77, I'll.'- 2-

18'Jil, ll„/w;u,i,(» A,/../-o7Ar— WiiiiriiKN i (icil. I(,.p. |llii..ii», V,,!. \ III., p. s.-i, I'Lilr 111, I'li; .-..

CmIvx liiLrliiT lliim wide, iini-sliaped, InmcattMl at tlio haso, llic lower edf^o s(>in;'wli;it project inif laterally and rounded olT. Dorsal onp liijrljer than tlic ventral ilisk, distinctly lolied at the arm re}:ioiis, contracted at the basi-radial suture, wlieiiee it spreails at lir.st iri'adiially, and then ra|ii(lly. to the arm hase.s, which torni a projectinf^ riui aroinid the calyx, i'lates luoder. iitely convex, without ornamentation ; the suture lines distinct.

ii.is.ils lai'i^e, foriniiii,' a sulicylindrical cup almost twice as wide as hij,di ; the inlerl);i-al .^utnres .•ilij.rlitly indented, liailials larj^e. jfenerally wider than Ioult. their median portions rai-ed into a transverse tuherde. Costals one third the si/e of the radials, a little widei- than loiij^ ; the (Irst (|nadran).'ular, the second ptM)tan,i,ndar. DistichaU 2^111; t'ollowcd hy 1x2(1 palniar.s which projcci upward and outward, and su]iport the arms. Ann facets directeil upwards. .\rms twenty; arranged in pairs, with deep depression.-^ hetween the rays, and smaller ones hetween their main divisions. Inter- braidiiaN : 1. 2, 'J. L'. the last two resting hetween the arm hases. Anal plate. (IS a rule, a little higher than the raili.ils ; succeeded hy three rows of thiee j)hites each. Interdistichals one, resting hetween the second distichals. Orals and r.idial dome ])lates — the latter of a (irst and second order — more or less highlv convex, contrasting considerahly with the small snp|de- mentary pieces surrounding them, which are ipnte numerous near the arm bases. Anal (ul)(> strong, almost central ; composed of large tumid jdates, which gr.adually decrease in size upwards. At a height of an inch and a halt from till- hast', the tube has a ring of live spiniferotis plates, the spines .sonu'- tii.ies nearly an inch long, and directed horizontally. Column stout, and. s(»

^\1

II

V

m«;«wWlMilMi

ppmpmmIi

I. JO

TIIK CHINOIDK.V CA.MKRATA OK NOKTII AMKUK A.

far as oIj.^uivlmI. of imili n size. To n Icn^lli of (il)oiit two int'lioH llio joints art' ot't'(|iuil It'iij^tli. and ilit'ic aii' mo inicinoilal joints, liut wla-n tlie latter make tlifir aiipciinuu'e, ihvy inoroasc lapiilly to seven to tlie inturnode, wliirli ceeins to liave been the niaxiiniiiii lunnber. 'I'lie upper joints, ami tlie nodal ones lielow, are rounded at tlieir edges, and project cunspieiionsly lieyond the sidi's of the inlciveninLT ones.

Il''il:jiii 11(1,1 l.iindll'/. — Keokuk limestone ; While's (.'reek Spriui:s. near Nasliville. Teun. ; IJulton .Mould Knol). Ky. ; Keokuk, Itnva, anil Warsaw and Nau\(io. Ills.

T'/jii.i in the (\Vorlhenl Illinois State coUeelion. Springfield.

Lobocrinus Xasbvilloo vn. Hubtraotus <\Viiiri). ri.ttr XSSI. J):/s. Ja. I:.

Wr2. .l,'ll,m,-riiiH^ SiinhvUl.f viir. uMi-m-liif— Wiint: ; rroccid. lt^l«^ Sdc. Xiil. IlUt , Ynt IX , p. in. |S>1 /!,!/■,• ,;,i,i< X.islintlil, \:ir. .iil>ifrili-liin — \\ . unci Sr. ; l(r\Mnl. I'iilil i , I'ail li , \\. \lu.

This variety dill'ers from the ly|iical I'orni in lieing less stronyly lolied at the arm regions, and in having,' no sjiue^ upon the ,inal tulie. 'I'he plates of the tulie are Imt slighlly eonve-., an<l eaeli one is surmounted liy a small I'onieal proiuiieranee in the centre. It also ilillers in the structure ol' the slem. lu specimens from ihe JJurlington limestone, and ISin'lington and Keii]\iik 'i'ran-ilion hed. ihi' proximal stem joints are shm'ter than the snc- ceediui:' one-, and 11 have an angular edge ; while in the speeimeus from the Keokuk liiU' -tone proper tiie e<lge is rounded. At thri'e inehe.s Crom tile c:d_\.\. all 'lem joints are nearly oT uniform si/e.

Il'ir'c.iiii tiii'l Lki'iI'iI'i. — I'pper ]iart of I'pper Hurlington limestone and nmlington ami !\eokuk Tran>itioa lied ; Di's Moines Co., Iowa; Henderson Co.. and Nauvoo, Ills.

I,'- niKi-k.i. — I )r. White gives the ahsi'uce of the intenlislichal ])iece as the piincipai disiiuction lietweiii the two forms ; this, however, is not a |h rsislent eharacti-r. We have a nimiher of s|iecimens from the true IJurlington lieils in which that plate is re|)resented in one lU' more rays.

Lobocrinus robxistus w, ami Sr. (iu'v. s|icp.).

P'li,' XXX. J'\'/s. ,V-/. /y,

,\ l.irgi' species. Calyx aliout as high as wide, deeply iind hroailly do- pre-'i (1 helweiu the rays. Ijorsal cup hut little higher than the ventral disk, the si'les >liyhlly convex, constricled at the hasi-railial suliu'es. Plates almost lla! u;!(l w.ti'.iiul ornimeniaiiou or other markings; sutuie lines somewhat trro'ived.

IIATOCUIXID.K.

487

IJiisnln uluirt. projcotiii}? ; fonniiij? n lioxitgoii ; cxcnvntcil at the Ijoltom. Railiitlx largo, wider tlian long. i'a|)iilly »<pri'a(liiig tu two thirds their height, their miper faceH deeply excavated in a foinewiiat siiiiiliir niiiiuier as the I'aeetH (if tho railial in the IMatycriiddiu. First costals more than twiee as wide as long. "ulKiuadrangular ; lower and lateral fact's eoiivex ; tho njiper ones straight. Second costals longer than tho lu'st, their sloping upper faces forming an ol)tuse angle. Disliehals 2 x 2 ; tiio first one largest; the sec- ond, although an axillary, scarcely angular aliove. I'almars 2 X 2, short, smaller than those succeeding them ; the outer ones of the seconcl row separated l>y iu'.erlirachial plate". Arm openings directed upwards, arranged in pairs. Interhrachials three, of wlii(di the lower one extends almost to the level of the arm hases; it is extremely large, hroad at tho bottom, taper- ing upwanls. There are three ]ilates in the second row, of which the middle one rests upon th(^ truneate(l upper lace of the first, the two others against tho adjoining sloping faces. Anal plate considerahly narrower than the radials ; (bllowed hy .'I, 2, and 1 plate. \'entral disk pyramidal, sup- liorliug a nearly central anal tuhe of moderate width. I'lates convex. nodo<(> ; the orals very large, especially the posterior one. Structnro of arms and colnnni unknown.

Il''ir:iiii Kiel L'lntlilii. — Keokuk group; White's creek .'springs, near

Nadiville, Tenn.

y.Vyd' in the collection of Waclisuiuth !ind ,'»pringer.

S

Lobocrinus pyriformis (Sm m.i.

Vial,- XXXI. /•■;,/,*. ,;,/-,'.

!'<.■).">. .l-ll'ni-riuHH iiyrifiriilif — SiiiMvlil); (JimI. |{i |i. Missmiri liv Svviillnw, \\x\ II. ]i. I'l-.?. ri:ite .\,

\Sfu> .lfi,i:i,;-i,iiit (rfr^ii'riiiiK) /i'/,-i/'ii;iii< — Una nuil WoiiTiiiv; I'mcci'd. .\c:i.l. X.il, Sci. IMiil:!.,

|v l.-|.'l; :iK..(i('Ml l<.'|>. jlliiM.ls, Vnl. II.. p. l.-,(l. Is;:) Il,il;,-i-ii<i'< iiyrifn,-i.ih — \Ikik .■iiiil WiiltTiihN; (ii'oj. H,'|i Uliiuiis, Viil V., |>. ;t7.'i, I'l.ilr .V rii;. 5. I'-il. Il.i/'i:'riiiiiii /ii/ii/'iriiih — W. niid Sr ; Ucvisinti I'lihinci' , I'.irl II , |>. U\7. Iss'.l. ll,i/„.-riii,i.' /iifri/ui;,n'ii — Nil M.WIl i |lii' SfnniMir (1. 'riiirnciilick. |i. IIU. Iml'. l.'U,

if\». .h-fiiiiiri-iiiiK pyri/arnih, \:\r. ri4'/if — Mkkk mill WouiUKv; ISi'iii, I'lucciil. Acml, Nut. Scl.

I'hilii, |>. i:il.' Syn. .l:-li,ii,.;-i,iiit (rii,'rni-riiiti<) iiitlilli/'iiniiii — M iiml \V. ; (!im| Id p. (if Itlmois, Vol II., (ilJl,

I'l 1 1, tU' ■-. .Syii. ISiilii.-riiiif pI'NIIi/oniih — \\. and W : iliiil. V..1. V.. p, ;W7.

.\ riillier kuye ntid v;n'inl)le species, f'.ilyx higher than wide, more or le-s pyiiform. and lint slightly depressed hetween the rays. Dors.il cup n;ir- row. iiU'l almiisi cylindrical to the top of the radials — sometimes to llie top

r'

SSBSBS^^EmRSI

MMM

< .1

488

TIIK tHlX(HI>i;A C'A.MKHAIA (»K Ndliril A.MKKKA.

of tlio coslals — wIk'Iicc it Hpri'iids aliniptly to tliu arm hasi's. I'latu,-! licnvv, tliuir iiiidillo [iDilions gcneially iJioiniiU'iit, tlioir .surlacfs .siiiuoili, and llic siiltiru liiiurt nut iniproMsoil.

llasi' onco and a half as wiilo ns lonj;. tniiit'atcd at tlic liottom. and cli^dilly Hjx'L'ailing out'.varil from tliu lower edge; colmnn I'ai'i't dci'iily inipro.swcd. Kailials large, gonuniily longer than wuU-, olU'ii iKcidrdly sci; rising vuiti- cally. Cnstals small ; the (irst (inadiangular, mH niuic than one I'Durlh the si/.o of the radials ; tho sucond a little ^^id^'l• lint not longiT than tho lir-t. Di-^lichals '2 X 1(1, of tho same si/.e a.s tho oostals. Kadi one is I'ollowed \>y two jialniai's, which eilhor form a conliniious Keiii's around tho calyx, or arc scpariitud hutwccn the rays hy a small intordislichal plate. Arm bases pro. jecting ; the arm ojicnings directed ohliijiiely upwards. Arms four to the ray. sliorl. rather llat and heavy. They are composeil of two rows of short pieces alternately arranged, which are produced laterally into slender, sharply pointed spines extending out from the sides of the arms. Interbrachial plates 1, -, -, followed sometimes l)y another narrow plate. Anal plate as large us the radials ; supporting three smaller plates in the lirst range, and three in tho second, which are IVeiincntly lollowed liy one or two other jjlates. Tegmen conical, slightly hulging ; composed of lar.i;(^ convex or nodose pieces, which are continued to the anal tidn'. Orals excentric, and a little larger than the surroumling plates, especially the posterior one. The radial dome jilales arc nNo readily distinguished l»\- their larger si/e ami greater convexiiy. Anal tu!)e almost central, very long and heavy, often rising to three times tlie length of the arms; it gradually tapers, and has at the ujiper end a minute o|)ening. Column long, rather stont. It has liecn ohserve<l to the length of twenty inches, to which it neither increases nor decreases in size, anil tin,- length of the joints remains unaltered; hut the edges of the upper ones are slightly convex, while the lower Joints are strictly cylindrical.

//"/•/■."/( iiii'! T.iii'iililii. — One of the leading fossils of the I'ppcr Huiiing- ton limestone, and I'uinid wherever that is exposed throughout Iowa, Illinois, anil Missouri.

liiimirl.t. — .1. j\>irll'iintii/i, var. ri'illt. is in our o])inion idiMitieal with this fspecies. The original specin\on was said to come from the Kinderhook group of Marion Co., Ills.; but we doubt it, for it is a true I'ppcr Burlington type.

li - J

IIATOCIUXID.i:.

480

LobOCrinUS SpiniforUS W. ami Sr. (mn-. gpcp.), I'hile A' A' A'. /'->. JI (tn.l IJ.

Of tlio type of A. X<iKltn7/tf, but ii miuiUit s|)t'cic.'<. Dorsiil cup (^I'licnilly n litlli; widi'i" tliaii IiIl^Ii ; I'loiii tlic tc)[) of llif Imsiils ;j:iu(luiilly fxpiiiidinj: to till; anil biiscM ; .Niilcs t'oiiuaM-. I'latcs very sliylitly couvl'X, tlic radinl.s .«ur- iiiuiiuted liy u siniill cuiitral nudu.

Ha.sal Clip twice as wide as liigli. narrower at tlic iip|ier end, tlie iiilcr- l)asal sutures j;ioovcd, iiii|iai'tiiij^ to the linsv, as ^een iVoiii tlic liotluiii, ii trilobate outliiu'. Itadials louder than l»)tli eo.-tals toj,'ctlici', and also liidadci'. The (Irst coslals ahout oiiee and ii hall' as wide ns Uuiji; ; the secoml wider aliovc than lidow. Distichals two, of the same propoitioiis as the two coslid- ; followeil Ity a siii;,de ran^'i? of paliiiars, which are laij^er than any of the ]pic- cediii;,' hrachials, and support the free arms. Ann facets directed obHi|uely upwards. Arms arran;:i'(l in jiairs ; those of dill'ereut riiys si'parated at their liases liy one or two inlerhrachiaN, those lictweeii their main divisions hy a siiij,'lc interdislichal. Arms short, cylindrical, very little taperinj;, and ourv- iiij,' inward ; tlic^- are composed of two rows of transverse jiieces, alternately arranu;cd and slij:hlly iiiteiiockin!;. I'innules very lon;^', in close contact; composed of elon_:^ate Hat joints. Interhrachials: 1, 'J. Ii. 1 ; the first lart;er timii any two of the others, the upper placed at the arm re^imis. Anal plato somewhat tidier hut narrower thuii the radials ; followed hy 3, o. 2. and 2 jiiates. The coii-itruclioii of the (li>U not visilil ' in any of the specimens. Anal tiihe loiijr, observed to an inch above the \'i\>< of the arms, but evi- dently loni,'er. It is composed of convex, slightly nodoso plates, but at ii lieii,dit nearly correspondini^ to the lips of the arms theie are from seven to eight plates with sharp, ^lender spines, o to 0 mm. long, which stand out iiori/ontully from the sides.

//"/•(';■"« (//('/ I. < nil I'll I/. — Keokuk groii|) ; Indian creek. Jlontgomcry Co., Ind.

7.Vy"'s' in the collection of Waidisiniitli aii<l Springer.

/tiiiiiiif,-^. — There is a slight possibility that liulnrnmn^ nmrhiiiK Miller and Gurley is iiliuti<'al with this species. We were imalde to make tiutisliictory comparison either with the description or figure.

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LobocrinuB eoquibraohlatui (M<('iiki<nkv).

jv^ik .VA7.V. /V'/N .V". /', <i',./ I'lui. xi.\ I. r,j^. (;„. h.

IWO. A''lillui-fiiill!i •riHlliriiikiitlllt — Mc('llt»N>ri Niw 1'iiIh'o/. t'lmi., |i i'.i.

I*il7i A'liiiiii'riHHi it'l'lilii'lhiiiiliit — MiChihmi i Trini'.. ( hii'. Ai.ul. Ni , |i I'", I'liilc 4, Ki(!». 8 unci 5

l*?'!. /*.//■«•/•/«». ./7'i'/<-//.'*/.(^«< — Ml I K and WnuniKN; <;■■.!, Urp llliuiiii, V..I, V., |). 3llt.

l>Sl, lliilurrinai ft'i'i'jriii-ii:i>at — \V. anil M. ; llitiMiin I';iIiimii i'ml II , |i. 1(1.'),

lliti'i'inciliiilo lii'lwi'i'ii l\iil,-'irlii'rri,(iix I.iirii iiiiil l.ifhni'rlniis i»irlfiin)ilf> : <1ilYi>i'iii^ IKiiii tlu> rui'iiii'i' in the iiiiiili lirmiilcr \n\>n\ iinil in liiiviiiL' lln' nnii liiiMi'M (liivctoil npwiinls ami iirningcd in jrrim|)» ; IViini I.. /i>/ri/"niiin in till' li'SM c'longiilc calvx, in the iIcpri-.M.^cd Inrni of (lit- vcniriil (li>U. tlio fiiinpar.'itisi'Iv liinLTrr arms, (Hill in llic f^linrlcc anil luoii' Klrnilcr aiiiil liilic ; am! iVoin liolli in liciiij; ili'riilcijiy lolicil liclwccii llic ravs. Calyx as lii^li as wiilc ; till! (lofsiil cup "iif lliinl liijjlicr tlian tin- vcniriil disk, liroadly Inni- oatfd at llio liaso. liic sidrs ciini'avr, gcadnally widtiiinj.' In tlif lop of lin' liist I'D-lals, tlnMicc rapidly sprcadiiij.' to llic ann fact'ls, vliicli aic diicclcd iipwaid. I'lati's of tlio dorsal cup pcrfi cily llat and cniootli, tlioM' of (lie vi'iilial disk more or less cnnvi'X.

li.i-als lorminjf a nearly cylindrical cup, more tliaii twice as wide a>. Idj;li ; iiiliiliMsal siiliiii's indistinct, Itadials iieiirly a> Ioiilt as wide, the upper end a lillle wider. First costals (|nadriinfrnlar, oiire and a lialf as wide as lon,i! ; till- second Ciilly twice as wide as long, lirplangnlar ; tlieir upper aiiijles olituse. Di-iiclials 'J X 'J, tliu second a.villary and laiirer ilian tlie oiln c l)railiials ; I'olloweil liy (V single row of ])almars. wliidi support tlie arms. Ann openiiivrs arrangeil in groups of two, tlio interspaces larger Ix'tween the Kiain rays than iietween their sulnlivisions. Arms twenty, of modciale si/e (iiid length, freipiently infolding at the top, whjch makes them appear shorter than they really are. Interhnu-hiids from (ivo to nine, geneiidly continuous with the iiitenunliulacral plates at nil sides, hut always at the pos- terior sidi-. Anal inlerradius composed of ten to fourteen piiMcs ; the amd plate higler tli.m tliu radials ; followed hy three ranges of three ]>lates each, and ft few narrow ])ieces interposed lietwecn the arm h.ises. A'entral disk depressed conical, the plates rather large and of almost eijiiiil si/.e. Anal tuhe nearly ceiitrid, composed of tiiinid plates,

Jf'ii\ii)i iiiiil L'liidliij. — L(jwer part of the Upper Burlington limestone, llurlington, lowii.

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ZiOboorlDui nqulbraohiatui ^.n. aatoriioui (Mkkk and Wuhtiicn). J'hik' A'A7A'. /Vyx. !/u, h.

ISAO .f'/mui'/iiiiM iix. 'Mi-iii — Mruk mill Wiiiimikn) I'ihc, AcimI. NuI S'i, I'liilii., p .tSJ ISOO. Ji'liHoerimii mltriieai — Mktk Hud WiiliTlltli ) Ui'iil. Ut'|i, llliiuih, Vol. 1 1., |i id'!. I'luto U, KIgt. H,(, *, ^

I87S. fliltilrriHMI IH/l-rUl'UI — MlKK Ullll UllHIIItM Ullll., Vlll. V , p llflS

ISSI. Hjii, .<f lliilufi-tHni iniuiiriiitiiiliK — \V. iiml Sr ; Idiiiniiii riiliinci., I'nrl II , |i IfiS.

8;ril. A:'liii"-riiiHii irnHilini'kiiilui, viir ii/i</ii< IIaM. ; ltii>liiii Jniirii. Nut Mini, |i. ^flM, I'linlnKr. rinli' X,, Wft. il ii; iiid WliilliiM; Auiir Mim. NuI llist., |su:«, Vnl. I., p. II, I'liiir I, KiK. II.

TIliN vni'iofy dilTorn from llii' typical Loliiii-rlinin ai/iu'/inicfiintim in lin' clioit. liosM of till' ciilyx, tliu liiitiit'HM ol' tliL' ventral (IImIx, in Nl'Iii^ inoru (lc'i'|i|y luitcd at llio arm liases, in tliu Imi^it Ni/.c of tlu- ciistul.i, nml in the cdM- (lition uf tliu inleibracitial ami intununlniiuci'al {ilate.t, wliiuli arc in contact nt all siilcH.

Ifin'iiiii mill Lni'iilit;/. — Upjicr niirlinjifon liniostonc, nurlinj;toii, lowo.

7.V/'<-' in tliu (Woi'tlicn) Illinois Stad- rollection. Siiringlielil,

LobocrimiB Yandolli rsm mahu). Phik XXX. ri^js. 7ii, h.

1S57. A.-liHwrinus J'i/«iA7/i — SinM mn ; 'rrnin. St. Kiiiiin Aiviil. Sri., Vnl. I., p 'i'\, I'liitr 1, FiijH.

I,/, «, <•. 1H7:1. Arlinoi-riiia' r,/»,/cW— MtKK iitiil WiiiiTlirs; (irnl. Kip Illiiini«, Vnl. V., p. IIU, bil. H,il'i,-rini(i YiiH'IrlU — W . ami Si' ; Itrvisiuii I'iiIihht, I'lirl II , p lliS.

A liirj,'i>, very knobby an<l nigoso siiecicH. Calyx doprosscil ; the ventral (li.sk from ono fourth to ono tliinl liij;ber tlian tliu dorsal cup, tlio latter ab- ruptly spreading from (lio top of the Imsals to tlie bases of tlio free arms, f Min- ing a low cup or basin, wliicli is followed by a eoniciil di.^k. The inter i.nliiil spiu'es are deeply depressed between the rays at the arm ba.^es, especially the posterior one which also is wider. The surface of the (dates is covered by prominent knob.s, either tran-versely or longitudinally arranged.

Ra.se short, Iriincated at the bottom; the lower margins projecting out- wards and considerably thickened ; the upper faces deeply emiirginnted toward the sutures, and the suture lines distinctly grooved, giving to the base, as seen from below, a decidedly trilobate as]>ccl. The column focct occnpioH ono half the width of the base, and is -lightly impressed, its sur- face crenulated at the margin. Uadials twice a.s wide os long; their upper faces a little concave ; the upper sloping faccM rather Mhort. The plates

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THE CHIN'OIDKA CAMKRATA OF NOUTIl AMEUICA.

are covered with conspicuous, transversely curved prominences, which nre studded with two or tiiree irregular nodes. First costals considerably smaller tiian the radials; the second smaller than the first, in some speci- mens pentagonal, in others trigonal. Dist.chals 2X2, larger than the cos- tals, especially the upper or axillary ones, which nre almost as wide as the radials. Palmars 2X4, larger than the distichals. They support the nrms invariably in three of the rnys, but in the two posterior rays the second plate adjoining the anal side is frecjuently axillary and followed by postpal- mars. The distichals are not placed on a level with their fellows of the same ray, but are alternately arranged, and the same is the case with the two inner rows of palmais; the arni-bi'r.ring plates being placed horizontally. The brachials throughout the calyx are covered with elongate elevations, and these again by a row of small nodes. Arms twenty to twentj'-two ; their structure unknown. Tnterbrachials: 1, 2, 1, and 2 between the arms; the first wider than long, its node transversely elongate ; the two of the second range longer than wide, and the nodes dispose<l longitudinally. The anal plate, which is longer than the radials, followed by three plates — the two at the sides wider than the middle one — and by three irregular smaller pieces, which in turn support several rows of elongate interambula- crals. The plates of the tegmen increase in size as they approach the middle; they are heavy, proportionally large, and the centre of each is crowned with a small tubercle. The anal tube is almost central, stout, and apparently long.

Horizon and LocaUty. — Keokuk group ; Button Mould Knob, seven miles from Louisville, Ky.

Types in the Yandell collection nt Louisville, Ky.

T

Lobocrinus longirostris (llALt). Plate XXVIII. FUjs. lu-e.

1858. Actimerintt!! hiigiroslrh — TIai.i.; GciiI. Rep. Iowa, Vol. I., Part It., p. 589, Plate 11, Figs. 4r, </,

ami i. ISr.l. Ba/ocrinm longirostm — Mf.f.k nndWoRxnKN; flonl. Itop. Illinois, Vol. V., p. 367. ISSl. Batocrinm loiigisrontrh — W. niid Sp. ; Ucvision Pnln'ocr., Part TI., p. 107.

Syii. Biitorriiiiii eassriliii/aiiiis — JIeek and WoRTiiEN ; Gcol. Kep. Illinois, Vil V., p. 370, Pl.ate 5, Firs, la, b.

Of medium .size. Calyx ovate, higher than wide ; the dorsal cup higher than the ventral disk; the arm bases a little projecting. Plates more or less

BATOCRIXIDJE.

443

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convex ; in some species quite prominent and the surface slightly rugose, in other? almost llat and perfectly smootii. Suture lines grooved.

Base short, hexagonal in outline, rounded at the bottom, the column facet slightly excavated, the interbasal sutures impressed. Radials wider above tlian below, deeply notched for the reception of tlie first, interbraehial, the upper face concave. Cosfuls rather large for the genus, together about equal to the size of the radials ; the upper larger and generally heptagonid. Dis- tichals two, smaller than the costals, the axillaries supporting 2X2 palmars, and normally four arms to the ray ; frequently, Iiowevor, the anterior rny has but two or three arms, and an additional fixed distichal in place of pal- mars. Arm openings directed obliquely upwards ; the interspaces separating the rays a little wider and deeper than those between the openings of the same ray. Arms from eighteen to twenty, long, rounded on the back, grad- ually tapering but not infolding, and composed from the calyx up of two rows of transverse pieces. Pinnules long and cylindrical. Interbrachials from five to seven ; the lower wider than long, and generally not rising to the fidl heijiht of the second costals. There are two comparatively large plates in tlie second row, and one in the third, followed by one or two irregular pieces, which separate the rays at the arm bases. Anal plate con- siderably longer than the radials, supporting three plates in the first, and three to four in the second range ; the succeeding ones irregularly arranged and interlocking with the interambulacral plates. Ventral disk depressed conical. Orals and radial dome plates a little larger than the interambulacral pieces ; arranged in the usual way. Anal tube stout and very long, rising in some specimens as much as G cm. bej'ond the tips of the arms ; the plates smooth. Column round, of medium size, the nodal joints rounded at the edges, the others considerably narrower near the calyx, but attaining the same width farther down.

Horizon and Localiti/. — Lower Burlington limestone ; Burlington, Iowa, and at several places in Missouri.

Type in the (Worthen) Illinois State collection, Springfield.

lioiKtrks. — We regard Batocrimtn casxcJai/mius M. and W., as a mere variation of this species ; the plates, although more convex than in the typi- cal form, are arranged in exactly the same way.

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444

TIIK CRINOIDEA CAMERATA OF NORTH AMERICA.

Loboorinus inflatUS (Howley and Hake). Plate XXX J V. Fij/s. 18, a, b.

1891. Hii/ocriiiiis injliilus — Howley and Hakk ; Kaiisiis City Scicut., p. 102, Plate 2, Fig. 19. Sju. Jialocriiius biilbosits — IIohlev iinj Uaue ; ibiJ., p. lU, I'lutc 3, I'ig. 5.

Cnlyx about as high aa wide, small, subglobose, slightly flntteiied nt the anal side. Dorsal cup more than twice as high as the ventral disk, deep bowl-shaped ; the plates heavy, almost flat and devoid of ornamentation ; the suture lines somewhat grooved.

Basals o little projecting, forming r low cup with a shallow concavity at the bottom. Radials wider than long, as large a.s both costals together. First costal quadrangular, small, wider than high. The second costal gener- ally heptangular, considerably larger than the first, wider as well as longer. Distichals two, rather large, those of the anterior ray, and the outer ones of the posterior rays, supporting directly the arms ; while the inner ones bear a palmar on each side. The anterior rays of the type specimen are abnormal ; tlie ray to the right is formed like the anterior one, and has but two arms, that to the left supports palmars nn both distichals, and has four arms.* Arm facets somewhat projecting and deeply concave; they point slightly upwards, and are arranged in groups. Interspaces between the rajs wider than tho<e between the main divisions of the raj's, and consider.ably wider tiian the spaces between arms of the same division. There are no respira- tory jiores near the arm openings. Arm structure unknown. Regular inter- brachials : 1, 2, 2 ; the first very large, as wide as high ; the two upper ones interposed between the arm-boaring pieces, and followed by disk plates. The anal plate supports : 3, 3, 2, and one plate, the latter being designated more properly as a plate of the disk. Ventral disk .small, the anal tube occupying almost one third of its diameter ; the plates nodose, and of nearly uniform size, even the orals cannot be distinguished. Anal tube heavy at the base and central.

Horizon and Lncality. — Lower part of the Lower Burlln^rton limestone, Louisiana, Mo.

Tijpcs in the collection of Mr. R. R. Rowley.

• In aiiollicr fragmentary sptciinoii in Mr. Rowley's collect ion, the riglit antcro-latcral ray, the only one seen, lias three arm openings, one above the distichals, the two others above a palmar. This is |irobably the normal arrangement, and there arc fourteen arms to the species. The type of H. ballnMim curiously also has but two arms to the right and four to the left.

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HAT0CRINID7E.

445

Benmrks. — We regtird Batocn'mts huJhosus Rand II. as identical witli tliia species, ultiiough the type specimens siliow slight variations. Tlu- dislv of "■ B. bulbuma " is somewhat more depressed, due perhaps to outside pressure, and the plates of the disk are less convex ; but variations of this kind are known to occur witiiin the limits of almost every species. Tlie two speci- mens agree essentially in the arrangement of their plates, in the mode of branching of the arms, they have the same number of interbrachials, and these connect in both forms with the plates of the disk.

( P) Loboorinus Hageri (SltCnESNEv.) Pktte XXX. Fi<js. 9, JO.

1S60. Ac/iiioerinii» ITiit/eri — MiCiiksnky ; Niw Piilreoz. Fciss., p. 2S.

1807. Ac/iiiorriiiii.i lliir/pri — McCiiESNKV i C'liiciigo Acad. Niit. Sici., p. 21, Pinto t. Fii; 1.

1&73. Balocriiius Ihigrti — Meek ami Woiitiikx; GpoI. Ucp. Illinois, Veil. V., p. 3(17.

18S1. Ba/orriniit Hageri — W. and Sr.; lU'visioii Pnlspocr, Part II., p. Ififi.

Approaching Dtz>/gocnnus rotumhis, but the dorsal cup more conical and proportionally uglier; slightly depressed between the rays; the anal tube smaller and tnore excentric. Plates flat, without ornamentation, and the suture lines indistinct.

Basals forming a low saucer-shaped, hexagonal disk, rounded at the bot- tom, and excavated for the columnar attachment, which is small. Eadials half as wide again as long. First costals quadrangular, three times as wide as long, the second wider than the first, Distichals in two rows, those of the upper row wider and axillary ; followed by 2 X 2 palmars, which support the free arms. Arm opening.s directed obli((uely upwards, arranged in groups of four, with a slight indentation between the rays, of which that at the pos- terior side is considerably the deeper. Arm structure unknown. Inter- brachials : 1, 2, 2, 2, the upper row in contact with the plates of the ventral disk; the first jdate smaller than usual in this genus, and fre- quently not reaching to the full height of the second costals. Anal plate a little smaller than the radials ; succeeded by ,3, 3, 2, and 2 plates. Ven- tral disk .slightly grooved at the posterior side, depressed convex, the plates nearly flat and almost equal in size. Anal tube excentric, very narrow and short.

Ilorhon and Locali/ij. — Upper Burlington limestone, Burlington, Iowa.

Tz/jje in the (Worthen) Illinois State collection.

Betnarks. — We have placed this species somewhat reluctantly under

446

THE CRIKOIDKA CA5IERATA OF XOKTII AMEUICA.

Lob'ivriiiiis, from tliu typical form of which it differs in having a diniinu- tivo anal tiihe, whicii occasionuily i.s reduced to a mere opening from the legmen, similar to that of Voiy/criiiits. It departs from JJiiforriini-i in tiic same character, and in being distinctly lobed between the rajs, the plates forming the arm bases are separated by interlirachials, and the arm openings are directed upwards ; in all of which it agrees with Lol/ocriniis.

MACROCRINUS W. ami Hv. (nov. gen.). (Maxpu! long, K/ji'cm' a lily.)

Calyx biturbinato or subovoid, the jjlates in part elevated. It may be pointed out as a structural peculiarity of this genus, tiiat the radials. anal l)late, and first interbrachials are generally nodo.so, but the higher brachials and interbrachials almost Hat and devoid of all markings.

Basals rather large, forming a subcylindrical cup. Radials frequentlj' larger than both costals together. Costals quadrangular and pentangular. The nmnber of disticlmls variable. Arm-bearing plates in contact laterally, e.\'cept at the posterior side, where they are separated by a small interbrachial plate. Arm openings directed outward. Respiratory pores in five pairs, placed interradially. Arms from twelve to si.\teen, long, subcylin<lrical ; tips incurving and sometimes tlattened, but without increasing in width. Regular interbrachials not numerous ; the anal plate generally supporting two rows of three plates, and a small piece within the arm regions. Ventral disk .shorter than the dorsal cup, composed of comparatively few large plates. Anal opening at the end of an unusually long tube, reaching far beyond the tips of the arms ; it is almost central, straight, stout at the base, but grad- ually tapers upwards .so as to be quite slender at the end.

Distribut'w)}. — So far as known restricted to America, and found only in tlie Upper and Lower Burlington beds, and in the lower part of the Keokuk group

T'ipc of the genus : Macromnns Koninclci (Shumard).

Rcmurks. — The species for which we propose this genus have been referred successively to Adinocrinus, Bn/orn'mis, and Erctinocrinus, but, as generally admitted, without agreeing with either one of them. They dif- fer from Bit/ocriinci in the more elongate form of the calyx, the less number and greater length of the arms, and in having but five pairs of respiratory pores ; and from Erctmom'nm in the arm structure, and in having a long, straight, and almost central anal tube.

BATOtHIXID.E.

447

MacroorinuB Koninoki (Siu<m.). Plate XXXV. Fijs. 1, 2, 3.

1855. Aflinocrinm Koiiiiicki — SnuMAUni (icol. Ucp. Missouri by Swallow, Part II., p. 194, Flnte A,

Fi(,'3. %u, li, e. 187H. Itdtiirriiim Kiiniiicki — JIekk nnd WoiiTiiENi Gciil. Kep. llliunis, Vol. V , p. 307. 1877. lliiluniiiiii Koiiiiifki — S. .\. Mii.l.Kii; Ciitiil. Aiiiit. I'alnjo?.. Vms., |) 17i. ISsl. EfehimrriiiKi Koiiiiii-ki — W. ninl Si' ; llrvisioa I'alieocr,, I'arl 11, p. 171) (Proceed. Acnd. Nat. Sci.

riiila., p. Ml). 1890. Ki-f/moi-riiiiit h'uiiinrli — S A Mii.r.KR; Xorlh Ainer. Gcol. niul Pal., p. 21H.

Syn. Adinoeriiiuf iiniirfu-'iit — .\I( Ciiksney ; 18BII, Dcscr. New Spec, of I'nss., p. 2:t.

Ciilyx urn-slmped, small, elnngnte. Doisnl ciip one third higlicr tlinn tiic vent nil di.sk, constricted iit the Ixisi-rndinl HUture.'*, wlniice it gradiinlly and unifoinily expimds to the bottom of the nrm-benring l)fiicliiiils, which are directed abruptly outward. All phites of the dor.fal cup are more or less convex; the radials, ar.al plate, and fir.st interbrachials strongly nodose.

Base rather high, wider at the lower end than at the upper ; the bottom truncated and hexangidar in outline; iiiterbasal sutures indistinct; the col- iinm facet bordered by a small circular ridge. Riuh'als large, as long as wide. Tlie two costals together not more than half the size of the radials; the first as long as wide, or nearly so, and quadrangidar ; tlie second larger, more convex, and pentangular. The three anterior rays have 3X2 dis- tichals and two arms; the two posterior rays toward tiie anal side but one distichal, followed by 2 X 2 palmars, at the opposite side three successive dis- tichal.s. Tiie two upper rows of brachials in the calyx are connected later- ally except at the nnal side, where one or two small plates are interposed between them. Arm facets small ; the ambulacral openings slightly grouped ; the space between the posterior rays wider than between the other.s, and somewhiit depressed. Rospirntory pores arranged interradially ; they con- sist of five pairs, are very large, and are located on a level with the ambu- lacral openings. Arms twelve, biserial, of moderate length, the tips infolding; they are slender, slightly flnttened on the back, and composed of short, nar- row, transverse pieces. There is but one interbrachial at the four regular sides, but four to six in the anal interradius. The annl plate is higher than the radials, and followed by three large nodose plates, and by one, two. or three in the next row. Ventral disk irregularly conical, the posterior oral pushed anteriorly, very large and more elevated than any of the other plates. Anal tube almost central, and composed of large, nodose pieces ; it

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448

THE CRINOIDKA CAMEUATA OF NOKTH AJIKUICA.

is long, xtout at the hiise, but qiiito thin at the upper end. Column Blender, the joints high.

Horizon and Lumlitij. — Lower part of the Upper Burlington limestone, Buviington, Iowa.

Tyije in the Washington University Museum at St. Louis.

i1

MaoroorinuH oarioa (Ham,). Flute XXXVII. Fig. S.

ISfll. Acliiiomnm carii'n — WkU.; Prilini. Descf. New Criii., |i, 10.

1S73. lliilo,;-iiiH3 {IW/wurriiim) airiru ; Mkek niiil UniiTllKN ; (Iccil. 11pp. Illinois, Vol. V., [i. 303,

1S77. Jliiloi'i-iiiua carifti — S. A. .\Iii.i,i;ii ; Aincr. I'liliniz. l'"i]ss.,|i. 71.

14S1. Ertlmoi-riiius Cdiird — W. mul Si'.; Itevisi' n I'liln'ucr., I'uit ]1 , |i. 172 (Proceed. Acad. Nat. Sci.

riiiiii., p. an'i).

IS'JO. Eretmocriiiim carica — S. A. MlLLEH; Noitli Aiiicr. Gcol. mid Pul., p 243.

Larger than tlio preceding species, and more robust. Calyx longer than wide, ovoid ; the dorsal cup one third to one half liigiier than the ventral di.sk. All principal plates of the calyx strongly nodose, the others flat or slightly convex ; the suture lines obscure.

Basals directed downward, deeply notched at the sutures, nnd slightly at tiie middle of each plate, so as to form six angularities or small nodes at the lower end of the base; the bottom forming a deep concavity, containing several joints of the colmnn. Eadials very large, wider than long, extended into a long transverse node which is directed obliquely downward. First costals small, almost linear, their surfaces flat ; the second arc nodo.se, pent- angular, longer than the first, and somewhat wider. Distichals 3 X 2 in the three anterior rays ; in the two posterior ones the divisions next to the anal side have oidy one distichal, which supports two palmars from each side ; the other divisions have throe distichals and no palmars, which gives twelve arms to the species. The distichals and palmars join laterally ; the plates are flat, except the arm-bearing ones, which are rounded like arm plates and project outward. Arm facets a little concave, directed horizontally ; the ambulacral openings almost equidistant ; the respiratory pores restricted to the inter- radial spaces. Structure of the arms not known. Tiiere is but one rcgidar interbrachial plate, the anal side has three above the anal plate, all of which are strongly nodose. Ventral di.sk hemispherical, constructed almost exclu- sively of the orals and radiiil dome plates, which are large and tuberculous. There are at each interradius three or four interambulacral pieces, which are scarcely convex. Anal tube slightly excentric, rather slender, its length unknown.

I

DATOCUIN'ID.E.

440

Horizon and Locallli/. — \]\>\tcY Biiilington limestone, Burlington, lowii.

TypcH in the Museum of Coinpanitivo Zoiilogy.

llcmarl'H. — Tiiis rnrc nud beautiful species is readily recognized by the peculiar form of its base, the large nodes upon the radials and interbraeiiials, nnd the flat plates in the upper part of the dorsal cnii. The nodes upon the radials hang downward, nnd their extremities reach almost to u line with the lower end of the basals.

i;v

(

i I

MaoroorinuB gemmiformia (Ham.). riate XXXVI. Fig. 8.

1300, Ai'liiioerimii gemmifuniih — IUll; Suppl. Geol. 'ncp. lown, ji. 23 (riio(o(;r.,Tliilc li./, I'i),'. 0, 1S"2,

N. Y. Sinic Musdini, Hull. !.)• 1873. Bdlocriniis (_Erelmucrinuii ?) gemmiformia — Mekk ami Woutiikn; Gi'ul. lU'ji. llliiiuia, V(il. V.,

p. 303. 1977. lliilorriiiin oemmlfnniiii — S. A. Mii.i.Kn; Catal. riilicoz, Fuss., p. 72. 1831. Kiv/mofriiiiii ffemiiii/urmis — \V. niid Si-. ; Hpvisiim I'lilitcicr., I'lirt II,, )i. 173. 1390. Efetmoerinm gemiiiiftrmis — S. A. Mjuleuj Nurlli Ariicr. Ocol. iiiiil l'iilii'(]iit., \i. 213.

A small nnd delicate species. Calyx a little higher than wide. Dor.-nl cup truncate at the bottom ; the sides moderately and uniforndy rising to the arm bases ; higher thnn the ventral disk. PIntes elevnted ; the radials covered with long tran.sverse nodes or obtuse spines, nnd similar elongate nodes, l)ut circular in outline, nro formed on the second costals, the first interbrachials, and the anal plate ; the distichals nnd pahnars angular on the back, forming distinct ridges.

Basals produced into long spreading extensions, which overhang the upper part of tlio column, giving to the base a decidedly trilobate outline. Radials large, a little wider than long. Costnls less thnn hnlf the si/e of the radials, almost as long ns wide; the first quadrnngidar ; the second pint- nngular. The anterior ray has 3x2 distichals ; the four other rays have in one division two small distichals, followed by two palmars, in the other three distichals. There are fourteen arms to the specio.s, exceptionally fifteen or sixteen, the odd number occurring in the nntero-lnternl rnys. The iii)per brachials nre in contact laterally except on the nnal side, where they are separated by an elongate piece, which connects with the plates of the disk. Structure of arms iniknown. Anal plate higher than the radials, supporting three large plates, and these from two to three small ones ; the interbrachials nt the four regular sides consist of two to three plates. Ventral disk hemi- spherical ; the plates large and sharply nodose. The posterior oral forms at

^ZPSssis::^:

400

THE CHIXOIDK.V CAMKHATA OK NORTH AMKUK A.

the anterior .siilo tlio ba.Mo of tlio vcntrol tiibo, which is lUiiiost ccntrul, ami inoru mIuikIui' thnii uhiiiiI in this ^enuH,

IIorixoH (inil Liicaliti). — Lowor Burlington limestone; IJuilington, lown.

Type in the (Worthen) Illinois State colleetion, Springlieltl.

Til iiiiir/i.i. — The Hpeeinien from which Hall nuulo his dcsciiption was (k'Cective, and the arm Ibrniulii which he givcH of the Hpecies is incorrect. It has nor-nnlly but Iburtcen arms: i,3; but when an additional arm is intro- duced, which is ([uito often the case, this is placed in tlio antero-lateral rays, and not in the posterior one. Hall gavo tho arm formula as i,i.

Maorooriaus verDeuilianus (Shim.)- r/a/c XXX. Fl(js. 15, 10, 17, IS.

1833. Jctiiioerliiii.'i vfriifiiiliniiii/i — SiifMAun; Gccil. Siirv. of Missouri by Swallow, Part II,, p. 1933,

J'latc A, KiKs. li/, h. 1H73. Jluloi'riiiiii fn-iieiiiliiiiiiii Mkkk iiuil WouTiiEX; Cecil. Hop. Illinois, Vul. V., p. 3*9, Tlatc 4, Figs. 3

ami 1. ISSl. Ei-rtmiiffiiiiis reriii'iiiliiiiiiis — W. and Sr. ; Revision rnla'ocr., Pnrt 11., p. 173 (Proceed. Acnd. Nat.

Sci, I'liiln., |i. ;U7) 1990. F.ri'tiiiociiiius veriieiiiliniiiis — S. A. Milleb; Ndrtli Aiiicr. Gcol. niul Taln'ont., p, 213.

Calyx biturbinate, higher than wide; tho dorsal cnp higher than the ventral disk, truncate at the base, its sides a little concave, the arm-bearing plates projecting. Surface of plates flat or very plightly convex, the radiala and first intorbrachials always more or less elevated at tho median portions.

Basals rather large, forming a hexagonal cup with erect sides ; grooved at the intcrbasal sutures ; the column facet deep and narrow, occupying but one third the diameter at the bottom of the calyx. Eadials twice as large as the two costals together, somewhat variable in form, but generally as long as wide, and tho lateral faces eonsideraldy longer than the upper sloping faces; the two heptagonal plates larger than the hexagonal ones. First costals quadrangular, very small, twice as wide as long; the second some- what larger and pentangular. Distichals two in both divisions of the anterior ray, and al.<o in one division of tho other rays ; tho other divi.xion has but one distichal, which is axillary, and supports 2X2 small palniars; there being normally foiu'tecn arms, with variations from fourteen to eighteen. First palmars in lateral contact with each other and with adjoining dis- tichals, except at the anal side ; while the upper plates meet only their fellows of the same ra}', being entirely free at one side. Arm openings directed slightly upwards ; the interspace between the posterior rays wider

t

^v

n.VTOt'UINID.V..

•l.-.l

tlmn tlioHo )iet\VL'en tlio otliiT iiivs, mnl imii'Ii inoro ik'pie-soil. Ifi'spi. ratory poros lurgo, in (ivu paiin, pluffil iiitciiiKlially. Aiiiih li>iiy. llio tips iiilolilinj^ ; coiiipoHcd of two neiioH of iiiodurntuly long pifces. Near tliu iippiT end tlio anii.M, wliifh liclow aiv roumlfd on tlio bai'k, grow alnui^i Hut, liowfvi'i'. without ini'ivaHing in width, and llio Murracc of each ])hitu in well prem-rvt'd Mpceinicns in covered willi two rtniail nodt's wiiich, fonned into longitudinal rows, give to tlio upper part of the arm a file like appearance. I'iiniules lon;^', conipo>ed of elongate joints, each one provideil with a «niall liook at tiie upper face. Regular interbraehials from one to three. Ana! piuto higher than wide, fol!(iwed hy 3, 3. and 1 jdate, the latter piece rest- ing between the nrni-bearing brachialH. Plates of the ventral dick almost Hat, except the posterior oral, w hich is moderately convex and very large ; it is erect, and forms at the anterior side the base of the anal tube. The tid)e is almost central, ver^- stout at the base, extremely long, attaining sometimes twice the length of the arms, and it terminates in a very slen- der point. The stem, which is known to n length of about lo cm., retains nearly tlie same width throughout. To the length o " about 5 cm., smaller joints altenuvtc at intervals with larger ones, thence downward the plates gradually become luiiform. The larger or nodal joints througliout the stem are al)out 1 nun. high by loss tlmn 2 mm. tviile. Toward the lower end ap- pear cirri, given oiY irregularly, and only one from a plate. Axial canal small, pentagonal.

lLifh:un ami Lvcii/lfy. — Upper Burlington limestone. It is found wher- ever this bed is exposed throughout Iowa, Illinois, and Missouri, being one of the two most common Crinoids of this horizon, and very characteristic of it.

I '

*l

MaorocrinuB juoundus (^i. and G.). Plate XXX. Flffs. 13, I4.

1800. BaloeriiiKS jifiiiulm — Mii.LtR niul (iriil.Kv; Jouni. C'iiicin. Sue. Kiit. Hist., Vul. X!II., p. iO, VhW \, Im-s. 5 mill C. Svu. /I,i/:ii'iiiiiia iir/iKitiix — S. A. Mii.i.Elij Adv. Sliccts l*(li Itcp. Gciil. Surv. Iiuliaim, 1891, p. 53, I'lalo "*, Figs. 1 mill 2.

A small species, the calyx subovoid. Dorsal cup higher than the ventral disk, truncated at the bottom ; the sides moderately convex ; the arm-bear- ing plates projecting outward. The plates in most of the specimens are almost flat ; in some, however, the middle part of the radials is formed into a

\i

I'

I

•I .".2

nil; CIMNOIDKA ( VMi;UAT.V OK NOUTII AMI.UI( A,

"iliDit, triinnvi'i.xe nodu, iiikI llie Iowit jiortioris of tlio (iiHt iiitoibiacliiiils aio .slightly tliickciiuil.

liiiNul:* hw^v, coMHtitutiii}( II xliurt cyliiulrical cup, fully twico un wide an tliu ('oliiinn, NuiiiL'tiinoH NJiglitly uxpaiiilin^f at tlii> lower end, and liex'ipmal in outline. KadiaN iniieli !ai>;er than the two eo^talw to^^elluT, wider than liuij,', the lateral taees eonnideraljly longer than the nloping upper one.x, tlio tipper liiecs slightly concavo. First costaJM quadrangular, one third wider than long ; the xecond pentangular, wider and longer than the Hint. DIh- tiehals 2 X 'J. throughout the ealyx, hut those of the anterior ray are nuc> ceeded directly hy the anus; while in the posterior rays, in the division ne.\t to the anal side, and in hoth divisions of tliu antero-lateral rays, tho secoiul distiehals arc axillary, and support a palmar from each side. Arm openings directed slightly upwards; almost equidistant; the arm-hearing plates in contact laterally, except those facing tho anal side, which are separated hy a narrow, elongate plate. Arins sixteen, moderately long, rounded on tho hack, giadually tapering to tho tips, and composed from their bases tip of two series of rather long pieces. Pinnules long, the joints elongate. Inter- brachials two to three, those of the second row comparatively largo. At tho anal side also, the upper plates arc largo for thi.s genus; the anal pinto is higher than the radinls, and succeeded by three plates, which arc as high and almost as wide as the corresponding single plate at the other sides ; the threo plates of tho second row are fully as large as the axillary distichals. Ventral di.sk conical, the plati's large, nodose, nnd extended into a long contrnl tube, which reaches far beyond tho tips of tlio nrms. The tube is stout nt the base, but gradually tapers to a sharp point at the end, nnd is composed of similar plates as tho disk. Tho posterior oral is pushed far out to tho nn- terior side ; it is three times as largo as tho four others, more prominent, and arranged trnnsvorsely. Column small, the nodnl joints rather high, witli rounded edges, and wider than tho intervening ones. At 4 cm. from the calyx the last intornodo contains seven pieces.

Horizon (Old Locidlti/. — Keokuk group; Indian crc^k, ten miles from Crnwfordsvillc, Montgomery Co., Ind., where it was fcand by ns in large numbers and in excellent preservation.

licmarl-n. — Ba/orrimin af/iintun S. A. M'''.er, is identical with this species, with only two arms iu the anterior rny in place of three.

i

r:

lUroCHIMD.K. J.".;}

Haoroorinui lagunoului (Hall).

ItftO. .f'/lnocrlHHi liignHfKlHi— II»i.i, ) 8ii|i]il. Ociil. lli-p. lown, p, 41.

1S(17. Hiilofriiim liii/mn-nlin — .\1. iiiul W, j (linl. Uep. Illiiidis, V.il. V., p, SOT.

l!l9l< llilmriiiHi IiijhhcuUi — W. uiij Hi'. ) lluviiiiiii riiliiiici'., I'lil't II , |i. HID,

A V017 NiiiiiU Hpocii'H of tlio typo of Mueroninus vcniniillnmis, but tlio (lorrxtl cup propoi'tioiiiilly luii^or, ami tliu ariii upiMiingH foriiiLMl into an iilmiist coutinuouH ring nrouml tin; ciilyx. CiiIy.K oiil-o mikI iv Imlf as high ns widu. Dorsal cup conical, iim high a.s thu widlii at (ho aim liases; tlio aiilus II littlu convux. Surttico of platuit Hlightly cluvatcil, atul huvuluil at tho margin-*.

Hasul.H inoiloratoly short, thickened nt their lower margins, nnil forming a riui, which i.s not iiideutcd at Iho HuturuH. Iliulials longer than witle, the superior faces concave. First costiils twico n.s wide as long, quadrangular; second costals pentagonal, exceptionally hexagonal in tho postoro-hiferal rayn. Tho anterior ray ha.s 3X2 disticlmls and two arms ; tho antero- lateral hi", one disticlml and four arms; while tho two poslero-lateral ones, which sustain three arms, have toward tho anal side a disticlml and two palinars, and at tho opposite sido three distichals, making sixteen armH to tho entire species. First anal plate as largo as the radials, slightly longer but narrower ; the second anal a little larger than tho two interbrachlals aside of it. Tho next row consists of two or three pieces. The four rcgidai' sides contain three plates, which aro arched by the arm-bearing brachials, and also those of tho posterior side. Tegnion conical, gradually passing into tho anal ttd)e, which is very stout; plates nodoso, decreasing In sizo as they approach the arm-bases. Orals excentric ; tho posterior one standing erect, to one sido of the anal tube.

Iforhiin (Old Loculitij. — Keokuk group; Warsaw, Ills., and Keokuk, Iowa.

Tiipe in tho Illinois State collection, Springfield.

1T^

4

454 TUir CKIXOIDEA CAMKKATA OF NOIMII AMEIUCA.

DORYCRTNUS Hoimku.

1S")4. K. lioKMEii; Aicliiv, f. Niiluif,'cM'h., Jiilirf;. XIX , Blind 1, p. M7.

IS'iJ. I'. li(iKMi;ii ; Lrlhiua (lini;ii. ( \ii-i,'. 3), p. 210

ISd'J. Mt'KK ami AVouriiKN ; I'loiTiil. Ai'.'l Nut. Sci. I'nilii., )i. 105.

1S73. Jh-.KK anil Woinjitsi (iwil. Ui'|). Illinois, V'l. V., p. 3('J.

1S7S. W. ami Si'. ; I'lucTil. Acail. Nal. Sci. "'Iiila., p. HH.

l""?'.). ZiTTKi. (sul)i,'i'nu5 111' .liiip/ioriirriiiiif) ; ilamlb. ilir ruliinnl., Vol. I., p. 370.

l^Sl. \Y. ami Si'. ; lU'visinii I'alaMicr , I'arl II., p. ITU (I'riim-il Acad. Nal. Sci. I'liila,, p. 3,ilO'

Syii. .tiiiphoi-iicriiiiis .Mi.';k and )ViiuTni:N (mil Ansliii, ISCjCi), Guul. Hip. Illinois, Vol. II., \>. 2nO.

Calyx iloci'.lcdly- bilateral, distinctly lobed at the nrm rogion.s, the iiiter- railial .spaces deeply depres.sed and simiou.s. The dor.sal cup broadl_\- trun- cate at tiie bottom, tiie plates heavy and frequently nodo.se. Basals three, largo, their sides produced into a rim which sometimes becomes highly con- spicuous. Radials, as a rule, as largo as the two costals together. First custals quadrangular; the second usually pentangular, excei>tion!illy hexan- gular or heptangular. Distichals two when there arc no palmars, but when the latter are reprosenled, there is but one distichal, which is axillary, and is followed by a single row of palmars. Arms in pairs, given off from a niimite axillary, which occupie-* the same facet with the proximal arm plates at each side, and both arms have a common ambulacral opening in the calyx. In sj)i'cies with twenty ari.i openings, each ray has four pairs of arms, but when there are les3 than twenty, the anterolateral rays generally have but two pairs, and the anterior one from two to four. The arms are rather short, biscrial, and more or loss spinous. The spines are given off at intervals fi'.>iu the sides, and are formed by the outward prolongation of the arm pl-itos. Pinnules of moderate size. The number of interbrachials is lim- ited, there being rarely more thr.n throe in the dorsal cup, the two upper ones at the level of the arm bases. The anal side is more or less flattened, the median line elevated, the sides grooved. It consists of a longitudinal row G.'' anal j)!atos, supiiorting a number of smaller pieces, which surround the anus. At each side of the anal row there are one or more interl)rachials, somewhat depressed below the level of the anal plate between them. Ven- tral disk highly elevated ; the iwsterior oral, and frequcntl3' also the first radial plates above the ambulacra, extended into low spines. Anus cxeen- tric, opening out laterally directly from the disk. Column round, the nodal joints largely projecting over the others; axial canal small, pentangular.

Dixtriliiit'ion. — So far as known, restricted to the two Burlington beds, and the Keokuk limestone.

i*.*'

T

T

lUTOCRlNin.-E.

•l.j.j

Ti/pc of the i^cniis : Don/rrhiHs mU^kf^ippicnm Roomor.

Utinttrhs. — In tlio Revision, Purt 11., wo referred to this ^axwm Doryni- nns cana/icitlatiii nnd Ac/iiU'criitiis {Cahcrimts) co/icuntx Meek nnd Wortlien. Ar/inncriiiiis mibnctthttus Hall, ami A. parvus Slniiimrd, all of wliieli wo liiivi> now arranj^ed under a new goniis Aurwrhius, along witli Jhn/iriiiiis iiiiiiid- (iini.'f, D. parrllidsin, and I), nidliititu, described by us in Vol. VIM. of the Geological Report of Illinois. The arms of those species, instead of being paire<l, are stouter and single, the first radial plates in the disk are not s])ini- ferons, nor in any way distinct from the snrrouiuling pieces, and their basals are small and roimdod at the lower margins.

Dorycrinus mississippiensis i?okme:i. PlKk: XLTIf. Fig. J, ami Flak XLIV. Figs. 2, 3.

18.it. HnKMKii; .\irliiv. f. Niiliii;;. (.l.ilir. XIX), Hand I., y. ell'., I'liilo 10.

1S()2. DiMUUMX anil llni:; lli^l. nalni-. ili's Ziiii|iliylr.s I'li'liincul., p. 1 Hi, I'liitc 3, l'i|,'s. 1-H.

1873. Mkkk anil WnnniKS ; (u'ul. H.'p. Illinciis, Vnj. V., p, 3S0.

1S81. \V. and Si'. ; Kcvi>ioM I'du-ncr., I'arl II,, p. 17'.) (I'rcioci'd. .\rad. Nat. Sci. I'lnla. p. 3."i:!).

Svn. Ai'liiwcriiiiis {lhiri/('riiiui) mhshsippieiisi!', \\\x. npiiiii/rr I1.\I.I. ; Siippl. (.ioul. Ui'p. Iowa, 1'>J9, p.,Vt.

A largo spocio.'*. Cal^'x about as high as wide, astoriform in its ventral aspect, deeply impros.sed and llattened at the posterior side, broadly truncate at the lower end : the ventral disk extended into six long, heavyspines ; the plates from almost Hat to strongl}' nodose ; suture lines niore or less grooved.

Basals large, forming a cup which is three times as wide as long, slightly expanding to the lower Tuargiii, Hat at the bottom, with a shallow depression for the attachment of the culunui. Radials once and a half to twice as wide as long, the n]ipcr face concave. First costals comparatively large, wider than long, quadrangular. Second costals a little larger than the first; those of the posterior raj's generally hexangular, the others heptangular. Dis- tichals one to each ray division, all of them axillary ; they are as large as the second costals, and give off from each of their sloping sides a single palmar, which supports two arms. Arm openings twenty, arranged in groups, tho-;o of the same ray equidistant, the spaces intervening between the rays twice as wide as those between their subdivisions, and that of the anal side al)out four times as wide. Arm structure unknown. First inter- brachial large, generally as wide as high ; it supports two somewhat .smaller plates, which abut against the upper costals and the distichals, and these are followed by two still smaller pieces, which are on a level with the

i

4-30

THE CRIXOIDEA CAMERATA OF NORTH AMERICA.

arm bases. First nnal plate longer than the radials, tlie median portions marlved by ii transverse ridge, followed by a longitudinal row of fonr additional anal.s, and these by a moderate number of irregular pieces which surround the anus. The four latter anals sustain at their sides a row of elongate plates, which decrease in size upwards. Anal area elevated, the median line forming a rounded ridge, which passes up to the posterior oral. Ventral disk inflated, as high as the dorsal cup, pentagonal in out- line. Tiie spines are long, sometimes reaching a length of 5 cm. or more ; the other plates of the disk (lat, or moderately convex. The posterior oral, which is represented by the central .spine, is as large at its base as the other four orals together; the latter are pushed anteriorly. Tiie first radial dome plates, which are represented by the five lateral .spines are surrounded by five rather large plates, and these are followed downward b}- two secondary radial pieces and a large interambulacral. Anus on a level with the lateral spines, the opening directed laterally.

Ilumon and Loml'dy. — Upper part of the Keokuk group; Keokuk, Iowa, and Warsaw, Hamilton, and Nauvoo, Ills., also found at AVhite's creek near Nashville, Tenn., and at several localities in Indiana and Kentucky.

TiijKs in the Mineralogical Museum at Breslau, Germany.

licinarks. — Since the above description was written, we have examined a fine spicimen in the collection of L. A. Cox of Keokuk, in which the arms are presurvea to near their full leng'J , and 13 cm. of the stem. The arms are paired and of moderate size ; they are composed of rather long joints, which are not spine-bearing .so far as observed. The column is rather heavy at the top. but tapers gradually from 8 mm. to 4 at the lower end. The first internodal joint exposed to view occurs between the eighth and ninth joints, but they increase rapidly in number, and soon attain the form and size of tiie nodal joints, which griidually become c^'lindrical and narrower.

Dorycrinus Gtouldi (TIam.). Plate XLIII. FUjs. 2, 3, and Plate XLIV. Fujs. 4, o.

l^jS. ArUiiorriiiiis Goiildi — IIai.i.; Ocol. Rep. Iowa, Vol. I., Piirt II., ]i- C13, Pliitc 13, Tiirs. Cc, I, c. 1S73. D'li-i/i-riiiiis GouliH — Mkkk iiml Wokthkx; Gcol. Rop. Illiniiis, A'ul. V., p. liSO. 1S31. Dnri/rriiiint Goulili — W. and Si'.; Kevisiiin I'alicocr., Part II., p. IT!) (rrocccil. Acad. Nul. Sci. ridln., p. 3.-):i).

Calyx about ns high as wide, crowned by six extravagantly- developed spines. Dorsal cup ol)pyramidal, ob.scurely pentangular to the top of the

,

BATOCRINIDjE,

457

-^

costals, the arm regions distinctly lobod, the interrndial spaces slightly flat- tened below and deeply depressed above. Plates formed into high nodes, which on the radials and brachials are transversely arranged and sharply angular, but on all interradial plates are circular and jwinted.

Basal cup large, distinctly trilobate, three times as wide as high, the lower margins projecting, broadly notched along the sutures, the bottom deeply excavated for the reception of the column. Radials once and a half as wide as long, rapidly spreading to two thirds their height, the r.ppcr face concave. First costals half the size of the radials and quadrangular ; the second generally heptanguhir, sometimes pentangular or liexangular, owing to the height of the first interbraciiials. Distichals one, axillary, narrower than the costals, giving off from each side an elongate palmar ; except in the antero-lateral rays, in which only the side of the costal toward the anterior ray bears an axillary, the other side two distichals, of which the second is twice as long as the first. The distichals and palmars have much the appearance of arm plates, being rounded exteriorly, so as to form a deep groove at each side. Arms arranged in groups, with wide and deep depressions between the raj's. When normally developed, there are eigh- teen pairs : Sjl, but most of the specimens have a few single arms irre- gularly scattered between the paired ones. Arms thin and short, rounded on the back throughout their full length, their tips slightly tapering. First interbrachial large, generally longer than wide, its central part extended into a conspicuous node; the two of the second row about one iialf smaller; the plates of the third smaller still, followed by larger plates in the ventral disk. Anal interradius very wide, flat, and exceedingly deep at the arm regions ; it consists of a longitudinal row of four large elongate nnal plates, with smaller pieces above, forming a protuberance and enclosing the anal aperture. At each side of the .second anal there is a large interbrachial, succeeded by several smaller ones on a level with the third anal. Ventral disk similar to that of D. iiimissi'ppkiish, and the plates arranged in the same way; the spines, however, arc somewhat longer, less tapering, and in the larger specimens are covered at intervals along the upper portions by small spiniferous nodes. The secondary radial dome plates, and the interambulacral between them, are somewhat smaller than in that sjiecies, and hence the height of the di.sk is a little less. Anal opening on a level with the lateral spines ; facing laterally.

Horizon and Locality. — Middle part of the Keokuk group. Rare at

II

.^

! . I

HOFWB' ■;r«fep.

458

TIJK C'KIXOIDKA CAMKRATA OF NORTH A.MKRICA.

Keokuk, iind generally crushed. Good calyces are found in Barren Co., Ky., and very excellent specimens with arms came from Indian creek, Mont- gomery Co., Ind.

Type in the (Worthen) Illinois State collection, Springfield.

licmarkx. — It is only iu very large specimens that every arm is paired, single arms being most generally represented in one or more rays. It is also interesting to note that our largest specimen not only has the arms all in pairs, but has in both antero-lateral rays four jMii-s instead of three, — the only exception among seventeen .specimens.

DorycrinuB oornigerus (IIai.l).

Plate XLII. Flfjs. 3 and G, and Plate XLIII. Fnj. 5, and Flute XLIV.

Fii/s. 0 (Old 7.

1858. Adinucrhitts cornigcrm — Halt. ; Giol. lUp. Iinvn, Vol. I., Pnrt II., p. 570, I'latc 9, Figs. Via, b, e, ami iliiil., Siippl., I'liitc 3, Fig. t. (Xiit Ai'lhiwriiiiis coriiii/ern.i Lyon niul Cass., '\^j'i=z Aorocriiiiis knitiifliiriisis). 1873. Durj/friiinx eofii'iiienu — .Mkkk iiiul WouTiiEs; Gcol. Hep. lilinijis, Vol. V., ]i. 380. 1881. Dori/erinns eornuimix — AV. iiiiJ Sp. j Revision Palicocr., Part II,, p. 17!l (I'rueocd. Acad. Nat. Sci. I'liila., p. 353). Syu. Afdmeriniis lUvaricatia Hall; 1859, Sup])l. Gcol. Rej). Iowa, p. 11. Syu. Acliiioeriiiiis (leeoriiiii ilihh; 1859, ibid, p. 13.

Calyx wider tliiin high ; the ventral disk as high as the dorsal cup. The latter turbinate, broadly truncated at the base, spreading rather rapidly from the top of the basals to the top of the costals, and thence more abruptly to the arm bases. The distichals and palmars form very prominent lobes with well defined sinuses between the arm-bearing plates. Plates smooth and almost flat, the suture lines but very ."lightly grooved.

Base large, the rim almost circular and without notches at the sutures ; almost flat on the bottom, the column facet occupying but one fourth of its diameter. Form of radials variable ; in .some specimens almost as long as wide, in others nearly twice as wide as long, the upper face excavated. Co.s- tals rather large ; the first quadrangular, once and a half as wide as long, the lower face convex ; the second wider but not longer than the first ; the sides spreading abruptly upwards; the three anterior ones generally heptangular, those facing the posterior side hexangular, the sloping upper sides straight, contrary to those of D. qiiinqudnhus, in which they are excavated. The pos- terior rays, and occasionally the anterior one, have two axillary distichals. which on each side support a moderately long palmar, the latter vny in the

BATOCRINIDjE.

459

majority of specimens only to the right ; while the antero-lateral rays have two successive ili.stichuls and no paliimrs. DiHtichalu and palniurs are dis- tinctly rounded off at the sides, like free arm plates. Ann facets semi-ovate ; the ambulacral openings directed slightly upwards, arranged in groups of four, two, and three (sometimes four in the anterior ray). The interspaces between the rays are wide, abruptly and deeply depressed, especially at the anal side, and those between the various ray divisions are deeply notched. Arms in pairs, two from each arm opening, long for the genus, incurving, flat- tened at the upper end, and every fourth plate giving off laterally from oppo- site sides sharp spines, 2 cm. in length. Interbrachials three, rather large, the two of the second row on a level with the arm bases. Anal area very wide, forming a low elongate ridge, grooved along the sides, which extends np to the posterior oral and contains the anus. First nnal plate as long as wide, followed by two other anals of smaller size, the two latter sustaining an interbrachial at each side. Ventral disk hemispherical, with six long, .slender, sharply pointed spines. The posterior oral, or plate bearing the middle spine, large and central, the otiier orals rather small and pu.shed anteriorly. The five radial spines are followed by two small secondary radial plates, and in rays with four arms b}- tertiary ones, which enclose an interdisticlial. Anus opening out laterally, placed at midway between the posterior oral and the arm regions. Column very gradually .sloping downward, with small cirri at the lower end, one to a joint, and at irregular intervals. The nodal joints of the upper portion of the stem are longer and considerably wider than those of the lower end ; they project conspicuously over the internodal pieces, but gradually decrease in length and width, and at 5^ cm. from the calyx have the same form and size as the others. The last two internodes in one of the specimens both contain .seven joints.

Horizon and LocaHty. — Upper and Lower Burlington limestone, Burling- ton, Iowa.

Tijpe in the (Worthen) Illinois State collection, Springfield.

liemarJis. — There can be no doubt that Acthwcriiiiis diraricatiis and A. ilfcorm's, both described by Hall, and afterwards placed by us under Dorycrinus, are mere variations of this species, as may be seen by com- paring a large number of specimens. The former is a very mature form, in which the anterior r.-xy obtained nn additional pair of arms ; in the latter, which came from the Loiccr Burlington bed, one or both posterior rays have but three arm openings, and, as a rule, the spines are shorter. The type

\> 1

ill

4G0

THK CRINOIDEA CAMERATA OF NORTH AMERICA.

specimen of Durycrinm cornii/cnis, figured in the lowii Report, is somewlmt mislendiny by having the iirni-benring plates broken. The calyx therein appears narrower than it naturally i.s, and gives no idea of the deep shiuses between the arm bases.

U i

|r

1959.

1873, 1891.

DorycrlnuB quinquelobus (Hall). Plate XLII. Fli/s. 7, S, 9.

Ai-lhwi'riiiiit qiiiiiqui'lohui — Hall; Suppl. tieol. Ucp. lown, p. 15, and N. Y. State Mus. Not. Hi»t.,

riate 3./, l''ic». 19, 19, mid 20. Dorycrinui qmn()iiflubus — Mkkk imd WiiiiTJiEX ; Geol. Rep. Illinois, Vol. V., p. 380. Sjii. of Ihrj/criiiuii rnniii/rriis Hai.i. — W. nii<l Sr. ; Ucvisiuii I'ulffiocr., Part II., p. 179 (I'rocccd.

Acad. Nat. Sci. Pliilii., p. 353).

A little larger than the preceding .•species and more robust; the calyx somewhat higher, broader at the base ; the sides less spreading and con- vex ; basnls produced downward in.-^tead of outward ; costals comparatively larger ; the plates, as a rule, more convex, and the suture lines more dis- tinct. Dor.sal cup pentalobate, as high as the ventral disk, constricted at the basi-radial sutures; the spaces between the rays abruptly, depressed, and forming deep and broad notches within the arm regions. Surface of plates smooth.

Basals large, broad, the margins of the plates overhanging the top of the column, and forming at the bottom a concavity, which is wider than the column. Radials once and a half as wide as long, the upper face the widest. First costals unusually large, almost two thirds the size of the radials, quadrangular ; sides and upper faces convex. Second costals penta- gonal, hexagonal, or heptagonal, considerably longer than the first, the upper sloping faces rather deeply excavated for the reception of the distichals. The posterior rays, and also the anterior one, have but one distichal in both divisions, which is short and axillary; its upper faces, like those of tlie costal axiilaries, are excavated, supporting a single palmar, which is remarkable for its great length, being fully twice as long as wide. The anteio-latoral rays in which there are no pnlmars have two distichals, of which the first is very .short, the second as long as the paliuars of the other rays. The great length of the arm-bearing plates is one of the best char- acters of this species ; they bend abruptly otitward, are rounded on the back, and are separated from each other by deep notches. Arm openings arranged in groups of fonr, two, and four ; directed slightly upward.

i

4

DAT0CR1NID7E.

461

Anns in pairs, bifuronting on a minute axillary, wliicli occnpios the same face witii tiie proximal arm plate ; tliey are rounded and composed of rather HJiort pieces, of which in the upper portions of the arms every third or fourth plate is extended laterally into a small node or short spine. Inter- brachials Jiree ; the first twice as large as the others, higher than wide, and with concave sides ; the two of the second row long and narrow. Anal area distinctly rounded, forming a low longitudinal ridge, with a deep groove at each side. The fn-st anal plate is generally a little narrower thnn the radials, and followed by a vertical row of three or four higher nnals, cpuid- rangular in outline, which support a subcircular nmnnnilloid protuberance containing the anus. Ventral disk highly convex, .«omewhat intlaled ; the posterior oral and the first radial dome plates extended into long, slender spines, the former central, and surrounded in mature specimens by about eleven convex pieces of nearly equal size, among which the smaller orals, if represented at all, cannot be identified. Similar pieces surround the radial spines, which enclose secondary radial plates. Anus at midway between the central spine and the arm regions ; facing laterally. Column moderately small, composed near the calyx of narrow and wide pieces alternately arranged.

Ilorhon and Loenlity. — Upper part of the Upper Burlington limestone, Burlington and Pleasant Grove, Iowa.

J'lJlie in the (VVorthen) Illinois State collection,

Dorycrinus intermedius Oi. and w.). rintc XLIV. Fkj. 1.

1868. Doryerinui qiiini/iir/oiut, vnr. iiilermeilius — Mkek iiiul WoHTHtx; Proceed. Acad. Nat. Sci. Pliiln. p. 34fl, and Ueul. Kep. llliiiuis, Vol. V., p. 383, I'lntc 10, Fig. -t.

Intermediate between Borj/criniis qninquehhits and D. mississippiensh. dif- fering from the former in its larger size, the more abrupt spreading of the dor.sal cup, the different form of the bnsnls, and the much greater length of its spines ; from the latter in having invariably but two arm openings in the antero-lateral rays; and from both of them in the enormous size of its column.

Dorsal cup rapidly and uniformly spreading from the bottom of the radi- als to the arms ; base broadly truncated, slightly projecting, and rounded at the lower margin ; the intcrradial spaces moderately depressed at the arm

< I

4r.2

TIIK CUINOIDKA CAMERATA OF NOKTH AMKIMCA.

ri'gioiis, mill not so dueply excavated nw in Honic otlior fniccii-s of this genus. I'liitcs more or lus.s tumid, tiioir «url'iice.s sniootli ; the suture lines ((uitu dis- tinct. Basalf large, longer than in D. mixKinsijijiiiiiKis, but not overhanging the column so far as in J). (jiiiiifjiitMius ; tiie sutures grooved. Itatlials once and a half as wide as long, rather deeply notched nt the sides. First coslnls ijuadrangular, the sides convex; considerahly wider than long. Second eos- tals generally heptangulnr, sometimes hexangular ; the sides rapidly spread- ing upwards ; twice as wide as long. They support in the anterior and the two posterior rays an axillary distiehal, and this from each side a moderately long palmar ; the two antero-Iateral rays have two rows of two distiehals. Arm openings foiw. two, and four, directed outward. Arms in pairs, rather short, curving, flattened in the upper portions, and so far as seen, tiieir sides without spines. Interbrachials three, the first twice as large as the two upper ones, the latter long and narrow, their upper ends rising to near a level with tlio bases of the arms. Posterior interradius as wide again ns the others, with a low rounded median ridge and a depression at each side. The first anal, which is longer than the radials, is followed by three other anals, of whieh the lower one is the largest; all have an intcrbrachial at each side, those of the lower row being as large as the proximal plate in the other four interradial spaces; the upper ones narrow, and resting within the de- pression at each side of the anal ridge. Ventral disk high, bulging, covered with si.x spines, of which the lateral ones in some specimens reach a length of 4 cm. ; they curve downward, and taper gradually to a point. The me- dian spine is straightcr and somewhat shorter than the others. The anus occupies the middle part of a small, sidjcircular protuberance, composed of from si.K to eight pieces ; it opens out laterally, and is placed on a level with the lateral spines. Column extremely large, fully twice as thick as that of D. miisissifpit'iiais although that is a larger species ; nodal joints long, rounded at the edges, and one third wider than the intervening ones, which are quite .short.

ILn-ivon ami Limdih/. — Transition bed between the Upper Burlington and the Keokuk beds.

I'l/l)e in the Museum of Comparative Zoology.

'!i

11

i ]

BATOCBINID/E.

463

Doryorinus missouriensiB (Sirmakh). Pla/e XLIII. Fiij. G, and Plate XL V. F!,js. IJa, I, c, ami I4.

1855. Acliiiui-rinui mmouriensis — Sui'Miuu ; Guul. Surv. of Misauuii liv Swallow, I'url 1 1., [i. 100, Pluto

A, Fi({s. 4rt, A, e. 1S73. lhri/rriii(i.i mhsourirnm — MtKK find WoUTIItN; Gi'iil. Iti'p. Illinois, Vol. V., |i. !i8(), 18S1. Duft/rrinm iimmiiirieiiHs — W . unit Si'.; Kcvi^ion riilii'iicr., I'lut 11., \\, 17U (I'mccdl. Acail. Niil- Scl. I'hiln., p. WWA). Syu. Aftinoeriiim ili'xidenilnx II.M.l. ; ISdl, I'nlini. Ucscr. of New I'uluoz. Foss., p. 2, anil Uusti.n

Jonrn, of Nul. Mist., p. Ii5.'t. Syn. Vori/criiiua ileniilerulii) — Mkek anil WourutN; Gtol. Ucp, Illinoii., Vol. V,, p. DSO.

A variable species, roniaritiible for the uxtravngant development of it.s basttl plates. Besides it diflfers from other species of this genus in the com- paratively greater height of the dor,sal cup, and the abrupt spreading of the disticiials and palinars, which stand almost at right angles to the rudinls and costals. Calyx a little longer than wide ; the ventral disk from one fifth to one foiu'th shorter than the dorsal cup. Plates thick, from almost Hat to strongly nodose, the nodes upon the nulials transverse and most conspicuous.

Base extremely large and heavy, spreading abruptly outward ; its dia- meter in extreme cases equaling the width of the dorsal cup at the arm regions, and reaching a depth as much as 15mm. ; interbasal sutures gener- ally grooved and frequently notched. Eadials about as long as wide ; the sides nearly parallel ; subquadrangular in outline ; the .sloping upper faces very .short ; the upper face concave. Costals very .■^inall, both together not more than half the size of the radials; their surfaces almost flat; the (ir^t quadrangular, twice as wide as long ; the second one no longer but some- what wider, and pentangular. The posterior rays have but one distiohal, which is quite smidl and axillary, and gives off from each side a single palmar. The antero-lateral raj-s have two disticiials, of which the second is twice as long as the first; the anterior ray generally has two disticiials to the left and one to the right, followed by pnlmnrs; but this ray also occa- sionally has no pnlmars, and two disticiials in both divisions. The arm- bearing plates, whether distichals or palmars, are twice as long as the preceding plate. The arms normally consist of fifteen pairs, arranged in groups of 4, 2, and 3, with wide and deep interspaces between the rays ; they ai-e short, rather stout for the genus, and bifurcate on a small trigonal axillary, which occupies the same facet with the ]iroximal arm plates. Arm joints of medium size, and each fourth piece is produced

,'•''. t

404

TIIK ( lUNOIDKA CAMKRATA OK NOHIIl AMKUICA,

into a Hiniill liiteriil iiodo. Firnt rugulai' inti'i'liruiliiiilH large, as wide nn long, and liiliciendous ; followed by two Hundlur tdongate, Hat pii'i-os wliicli rest bt'twei'M tlio arm bason. Anal jilatcs llirt'O, longitudinally aiiangcd ; tlio first nn largo as, or larger tlian, tlio radials; the two others somewhat smaller, supporting a subeirunlar mammillary protuberance, wliich is com- posed of comparatively few large plates, anil is pier(!ed by the anus. The po.sterior interradius has only two inlerbracbial plates, one to each side of the second anal. Ventral disk sidj-hemispherical, covered with five long, slender spines. The posterior oral, which in other species is represented by a central spine, is here nodose, and three times as large as the others. In rays with four arm openings the spine-bearing plates are I'ollowed by two double rows of rather large alternate pieces; but in rays with two arms they are followed by two single rows, the single as well as the double rows enclosing a large subtrigoiial interdistichal. Anus directed laterally, niid placed at midway between the posterior oral and the arm regions. Column comparatively snwill. the facet for its reception deeply depressed, occupying in dilTereut specimens from one sixth to one tenth the diameter of the basal disk.

Ifiif'r.nn and LoraHf//. — Upper Hurlington limestone; Palmyra, Marian Co., Mo., and Burlington, Iowa.

(■'

1868. 1873. IsSl.

Dorycrinus Roemeri Mkkk and aVohtukk. I'hte XL V. Fi<iH. loa, h.

Mekk iiikI Wouthen; I'mcct'il. .\u:iil Niil. Sci, Philii., \\. lilfi.

.Mkek 1111(1 Wuutmkn; (ii'ul. Hip. llliiiiii>, Vnl. v., p. 'i^'A, I'liilc 10, Fig. 3.

W. mill Si'.; Ki'visiiin riik-iior., I'm I 11., ]i. ISO.

Of the type of D. iiiissnnriciislii. Caly.x a little longer than wide, lobed at the arm base.«, the dorsal cup obconical. nearly twice as high as the ventral di.sk, gradually spreading to the top of the costals, thence abruptly to the arms. Plates heavy, convex to nodose ; the suture lines not grooved.

Basals .somewhat expanding downward, truncated and moderately con- cave at the bottom, about twice as wide as high ; the interbasal sutures .slightly notched. Radials one third to one half wider than long, thickened in the middle into moderately prominent, rather obtuse, transverse nodes. Costals convex, quadrangular and pcntauLndar; the first rather large, wider than long, the axillary a little wider in proportion. The latter supports npon its sloping npper faces in the anterior and both posterior rays an axil-

HATOCRIXin.r..

405

h\ry (linticlml, wliicli in turn yivoM olV two imliniirn, nno to each Hide; wliilc in the iintcro-liiU'iiil niy.M only tlio face towiiid the por'ti'iior riiyx Ijoiun nn nxillai'V, thi' ojipoj^ito liicr two disticlmls, wliich arc IVoniifntly unchyl(»'('il fo as to form one hirge piece. Tiie {listichals and piilniars are roundeil olT Inter- nlly, nnd rcHcnihle free arm phites. Arm openinj^s directed hori/ontally, ar- riingod in groups of 4, 3, and 4 ; the inter^'paces between tiie nrni" of the Haini' ray narrow and slijrlitiy f^rooved. tliose between dilVereiit ravM luiicli wider nnd (h)oply depressed. Structure of arms uni<nown. lieg'.dar interlnaciiials three; tiie Hrst largo, about ns wide ns high and tul)crculo«H, the two others. whicli are on a level witli the arm-l)earing plates, small, elongate and Hat. Posterior interrailius very wide; it consists of a longitudinal row of three anal plates, of which each succeeding plate is one half larger than that below, nnd four interbrachials, two at each side of the nnal series. The upper nnal plato supports a very conspicuous oval protuberance, which extends promi- nently outward, and projects upward freciuenlly beyond the central jmrt of the disk, giving to the calyx an asymmetrical aspect. Ventral disk depressed hemispherical, crowned with five radial spines ; the posterior oral, ns in. the preceding species, being merely convex or conical. The arrange- ment of the orals in this species is more symmetrical than usual in this genus, although the posterior one is not only larger thnn the others, but pushed in slightly between them. The spines, which arc comparatively short, tnper rapidly, nnd nre succeeded townnl the nrms by two small sccond- nry rndinl plates, and each of them by still snudler tertinry plates, which enclose a small internmbulacral. The nnus opens out laterally, and occupies the median part of the anal protuberance.

Horizon and Locality. — Upper part of Upper Burlington limestone; Burlington nnd Pleasant Grove, Iowa.

Ti/pe in the Museum of Compnrntivo Zoology.

livnnirlcs. — This species difTcrs from D. mlssouru'iim in the more conical form of the dorsal cup, in its much narrower bnse, in the extra vagnnt development of its nnni nrca, and in hnving nn ndditional arm in all three anterior rays ; all of which are constant characters.

I I

59

1 ■■

ICG

TIIK CKINOIOKA CAMKUATA Ol' NOHTII AMICKICA.

Doryorlnui aubturbinatui (M.iiini W).

J'l,i/r Xl.ll. I''l;/s. /()„, h.

ISilO. .leliHoiviiiHi (.liii/iiuruiriitii') niililiifliiiialiit — .MuN iiml \V(jutii(v; rrocccil, Acnil. Nat. 8cl.

I'liilii., p. :t'«H. ISOO. .l„iiihr,i,'fiiiiii/M/-/uil,iMlin — \l. iinil \V. | Or.il. It, p llliii,ii», Vnl. 11, y. Hi, I'lulf 15, Ki(;i.

t", «. b?:), /).,r/),;-liii4.< nil,tiirl,iimlH>— M. riiid \V. ; iliid . Vii V., |i. 11111. ISll. Iiuiy.'fiiiui >iil,ti4i-hiiiiilH.< — W. iukI Sr. 1 J{i>i!iicjii I'lilii'iiir., I'nrl II,, p. 170.

A .''iiiall spocioM, in llio I'di'iii dI' tlu' v\\\y\ rcii'iiiMing D. vn'usix.ti/ijilciisls. Dor.iiil cup hroiully olicuniciil ; tliu n'n\vn Htraiglit lioiii tliu culiiiiin to tliu imn liases, with ii shallow <lt'prt'Hsion nt tliu inlci'radial Kpiu-rs; the ravs not so (lisiiiu'tiy lolieil as usual in thin genus; plates Hut, and devoid of oina- nienlation or other markings.

lliisals small, I'onuing an ohconical cup, rounded at the lower end ; the colunni facet narrow, occupyiuj; the full width of the lower luce, liadials n little wider than loiij.', fully twice as wide as both costals together, the upper face concave. Fir:'t costals qnadriniuMdar. as wide ngain as long. Second costals wider than the lirst, gencnilly (|uadrangidar, exceptionally hexangular or heptangular. 'Ihiy support in the anterior and posterior ray.s an axillary distichal, and this, in turn, a snudi palmar from each side; while the antcro-lateral rays have two distichals and no palmars. Inter- hiacliiiiis one and two; the lirst large, as wide as long, the two others ns long hut one half nnrrower. Anal side very wide, a little bulging at the arm regions, incurving above, and elevated at the median line. Jt consist.< of three hexagonal anal plates, the first as large ns the radials but sonu-what longer and narrower; the other two decrease in size upwaril, and are lol- lowed by a number of smaller |)lato.s arranged around the anus. The anals from the second plate up sustain at each side an interbrachial, the lower pair ol' whi(di being nearly as largo as the corresponding single jdute of the regular side.s, the npper ones being m\ich smaller. \'eiitral disk dc- pres.sed-convcx, somewhat inlliited along the sides, llnttencd on top. The surface is covered with six spines, which are short, coming ra}iidly to a jioint. The middle spine occupies nearly the centre of the i pper face, the lateral ones are placed almost vertically to the arm bases. Arrangement of orals and radial plates as in the preceding species. Anus at midway between tlio posterior oral and the base of the arms, directed laterally.

nATOCUINMi.T;.

467

Iluvixon uiul Linulili/, — III tlio lower part of tlio Upper niiiliiigloii linu' Mtonu, not loiiiid iiltovo the nliile cr^'Mtalliiie livil, liuiliiigtou, lowit. 7j//'i' ill tliu llliiioiit State colluutioii, Spiiiigliulil,

M*

'n

Doryorlnua unlsplnua Ul'^ii)- I'tulc XLW, I'ij.n.

imll. ,fV('««i'c)'/i«,i i(i«(»y<i'/(».i — IIaiL' rrrliiii. Dene. NfW Ciiiiiiiilh, |i J, niul Iln,i .tuiirii. Niil. lli!.!.

1h7;1. lUiryrriiiH.i uni'/iinu.) — Mkkk niiil WimillKS ; (inil lli'|i. Ill I», Vnl. V., jp. :1S1).

l'^^l. llu.y.u-iiiHi uiih/iiiiHi — W mill Si' i Ui'\i-iuii riil.T.icr,, I'liil II , |i. Isn,

Sjii. J.'/iiwfriiim triiiwlw ll\l.l.; ISSS, (iiiil. Hi'li I'lWn, Vnl. I , I'liil II , |i 1573.

Caly.v moiIiM'iitcly spri'iuling fo tlie (op of tlic sccoml co.slul-^. mid tliciico more ul)iui)lly to tliu iii'iii.s; it U (li:<tiiu'lly tnincutuil tit tlio \n\!<v, mid, nt* Bot'H from iiliovf or below, Nomewimt peiitalobiito iit the nriii rcgioiiH. Yen- trill di(*l< deprcw.xe(l convex, one fourth to one third nhorter llimi tiie doi>:il cup, mid rro\VMe(I liy ii .ijnjrlu liuyc .-'piiio. Tiie phite.s of Imlli henii>[ihere.s nro not oriimiieiited ; tiiey are virtually (hit, with only the apparent convex- ity duo to the Nlight grooving oC the suture lines.

Uasals (brining a short cup, subeyliiidriciil in outline, often sli;^htl\- Kpreadiiig to the lower margin, excavated at the Imttctm enough to enclose the two proximal .^tein joints, and pierced by a small pentangular canal. Kadials ii little wider than long, as large as the two co>uds together, the upper face concave. First costals qimdrangiiliir. nearly twice as \\ide as long, upper and lower faces convex. Second costals ii little wider and longer. Number of arms exceedingly variable, with cons(>(|iient variation in the distribution of the distichals and the presence or absence of paliuars. The anterior and two posterior rays have either three or four pairs of arms ; in the latter case there is but one disticlial in both divisions, succeeded liv 2 X Ii palmars, but if there are three pairs, (ho two divisions next the anal interradius have no palmars. '|"he two antero-lateral rays raiel}' have more than two pairs of arms, and 2 X 12 distichals. Arm opeiiing.s directed out- ward, arranged in groups; those of the same ray separated from tlio.se <if adjoining rays by a deep depression. Arms incurving, rather stout for the genus, lliittened in their upper parts and serrated at the edges, but without increasing materially in width. Regular intcrbrachiala three, rarely four, the upper row on a level with the nrm bases. Posterior interradius wider. formed at the upper end into a longitudinal ridge with a deep groove at

II i ' 'I

4C8

TllK C'HINOIDEA CA.MKHATA OF NOHTII AMKUICA.

l I

uiU'li siile, I'oiu'liiiig up to llio iiostciior oral. It is composed of a seiios of foiii' to livu anal plates, loiigitmlinalh- arranged ; the first larger than tho radials; the second interposed between two interbracliials ; the third occupy- ing the arm regions ; the upper one followed by numerous irregular, small ])ieces, forming a tumor-like inllation whicii is pierced by the anus. Posterior oral central and drawn out into a long, shari) spine, which sometimes cxci''h1s in length tho height of tho calyx. Tho oiher orals are somewhat tiunid, as also the prinuiry radial dome phito.s; while the interambidacrul plates are alniost Hat. Anus placed at half way botwt.'en the arm bases and tho posterior oral, opening out laterally.

lliivhiin and Loodity. — Lower Burlington limestone ; Burlington, lowii (a rare species).

Tijpc in the LJnivoraity Museum at Ann Arbor.

Juiiiarl's. — ^' Af/iiiiicrliiii!<" /n'liodux Hall is an abnormal form of this species, the radial dome plates of tho two posterior rays, as in tho case o( " Ai'liiiiicr!itii)i" trlroniis, are produced into .spines. In tho IJovision, Part If., wo erroneously placed this form under " Dori/criiius" nz/iiiiiidrwiis.

|i|

Dorycrinus unicornis (O. and Sm m.), r/afe XL V. Fhjs. Sa-c, D, 10.

ISJO. Ai'tiiiorriiiii.i iiiiiri^niis — Given' niul SiuMAUii ; Jdurii. Acnd. Nat. Soi. Tliiln., Vol. TI. (new sor.^ |i. I'i7, I'l.iiu 7, t'l,!,'. 1:.'; \>'ji, I', y. (ii'ul. Surv. Wise, lunu iiiiil Jliuii , p. 5'.i;f, I'hilc 5-/,

18,'>S. .h'liiim-riiiiis i(iii.-nrnis — \\\\.\.; Gfnl. Hep. liiwn, Veil. T., Vint 11., p. 5fi8, Tliito 10, Fi(,'s. !),r, li, c. lsr;t. l>iiri/iviiiu.< ««/Vi//v((,v— Mi.iK iiiul Woihihn; (iiul. Hrp, llliiioi;., Vnl. V., p. ii'^l), Tliilc (1, I'igs.

Ill, h, c. IS^l. l)i:ri/i-riiiiit uiii-onii.i — \\ . ami Sp. ; lirvisiim I'liln'iior., Piirt II., p. ISO. IbDU. Ihi-i/i-riiiiis ttiii,;inih — S. \. Mii.i.Kii ; N'orlli AiiiiT (icnl. iiiiil riilivniil , p. 211, t'i.i; SPl- Svn. .l-/iiiorriiiii< Iri.'nriiii — ll.M.i.; IS'iS, (inil. Hep. Iciw.i, Viil. 1., I'miI II., p. W.\. Syii. Ihri/rriiiii.1 Irii-Dnih — WiUTKiKi.ii, ISDii, .Mrni. Am. Mils. Kul. lli^l. New Yiirk, p. 19, I'liite

lI.,Vii:>^. fi InS. Syii. ArliiKH-riiiiis iti-iiih'iis — TI.*i.T,; ISfiO. Siippl Geol. Hep. Iciwa, p. .■?!. Svii. Diiri/crinus iii'iiilrii!: — WiiiTnia.ii; IS'.i:!, Mem. Am. JIus. Niil. Hist. N. York, p. IS, Vlulo 2,

I'iir.'s. S.vii. Dari/irinini liiifnlim S. A. Mii.I.1.1! ; 1S81, .Tmirii. Ciiicin. Sue. Nat. Hist. (Deeemliei), I'lale 7,

1mi;s.'h, ;t„. Svii. Ih,,-;irj-iiiiis iiilliifiit lidWl.iY ami TI.^liE; 1891, Kansas City Relent., p. lit. I'lale 8. ^i^^ ■!■.

("alyx spheroidal, broadly tr.uicato at tho lower end. modcratol}' spread- ing to the top of the co-itals. thence nbru])tly to the l)as,i of tho nrina. ^\'n- tral disk almost as high a-; the dor-^al cup. iiillated at the posterior side, and crowned by a long central .spine. Plates of tho dorsal cup highly elevated ;

nATOCRiNin.T:.

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those of tlio radial .series formed into conspicuous, angular, transverse nodi's, the interradial plates into large rounded or pointed lubereles.

IJase snuill, short, liexaugular in outline, slightly noleiied at the suture lines, excaviiteil at the l>()tt()iu to enclose one or two joints of the eoluuin. Riidials n little wider than long, the leuglii of (he lateral margins ahout eipial to the width of the upper and lower i'aees ; the upper sloping f'aees small. The nodes of the plates direeted olili(pu'ly downward, and their extremilies reaching tiu> level of the lower face of the hasal.s. First eostals short, t|uad- rangular, mow than twice as wide as long. Second coslals a little longer, pentangular or suhtriaugular, their lateral faces .short. Disliclials larger than the coslals, then; lieiug two in the three anterior rays, which directly sujiport the arms. In hoth ])osterior rays, the division facing the anal intcrradius has but oim distichal, followed by two series of two iiahmirs ; while the otlu-r division has two distichals and no palmars. Arm bases lu'ojccliug. iudiuited at the sides, the interspaces between the rays wider than between their sub- divisions, and the space l)etweeu the posterior rays still wider. Arm facets large and liuiate, the ambulacral openings f;u'ing outw.ard. Arms in twelve pairs, long, stout, infolding, rounded at their bases, llatteiu'd and wider in the 'ippor portions, and composed of two series of moderately short i)icces, which grow longer upward. Some of these pieces are produced at the outer side into small nodes, which higli(>r up in the arms turn into short, (piite conspicu- ous spines. Near the calyx only every third plate bears a node, but through- out the llattened portions of the arms ev(M-v other jilate. Interbrachials liiree ; the two upper ones eloug.'ite, resting between the arm regions. The plates of the posterior iuti'rradius consist of live or si\ large anal plates longitudi- nally arranged, of whicdi the two upper take part in the ventral disk; and two interbrachials. out; at each side of the second anal. The upper anal plate supports a number of small, irregidar pieces, forming together a turgid elongate area, whicii near its upper extremity contains the anal opening. Plates of the ventral disk highly ccmvex, .sonuMimcs conical, covered in well preserved spcciuuMis by small verudcular graiud(>s, except those sui'roundiug the anus, which are perf(>ctly smooth and almost Hat. Orals large ; the pos- terior one central, and extended into a long, .slender spine. The lliod grooves are covered by three large ])lates of a first and second order, of which sometiuu's the ]irimary plate in one or i)oth jiosterior rays is spinous, while in most specimens these plates arc no more tiiini<l than the three others. Approaching the arm openings there arc two secondary railial plates, which

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470

TllK CKINOIUKA CAMKHATA OK NOKTII AMERICA.

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enclose a large iiitorclisticlial. Column composed of large and small joints, the larger or nodal joints increasing in width downward, and at 4 cm. from the calyx are twice as wide as the intervening pieces; they are also much longer and angular at their outer edges.

Horizon and Locality. — Lower Burlington limestone; Burlington, Iowa, Sedalia, Mo., and Lake Valley, New Mexico. This is one of the most char- acteristic species of the lower Burlington division.

licmarks. — Aclliiocrinus tricanu's and A. jic/h/ciis, both described by Hall, are undoubtedly specifically identical with Donjcriinm unicornis. In the first tiie posterior radial dome plates are extended into spines ; in the second the nodes of the radials and first anal plate are " elongate and subclavate, being contracted in the middle, and swelling out at the extremities." Among this variety also we find specimens w^ith one, two, or three spines upon the ven- tral disk, which are comparatively longer in j'oung specimens. In the sjieci- niens from Pike Co., Mo., described by Rowley and Hare as Dorf/criims injlutns, the plates of the dorsal cup are less angular than usual in this genus.

AOROCRINUS W. and Si-, (nov. gen.).

('Auipo? iiniii.tturp, Kftirov a lily.)

The species small. Form of the cal3'x and arrangement of the plates similar to Dorijcrinux. As in that geiuis, the arms are arranged in groups, and vary in nuudjer among the rajs, the anterior ray generally having the fewest. The arms are stout and packed closely together, there being invariably but one arm from each ambulacral opening in the calyx. The ventral disk, as a rule, is shorter than the dorsal cup, the plates are smooth or slightly convex, except the posterior oral, which isniore or less elevated and frequently tuberculiform, but not actually spinous. The and)ulacra are tegminal, and covered with two rows of small pieces. The anal area is com- posed of small plates, generally forming a protuberance or low ridge, which slopes downward almost in a straight line from the edges of the jiosterior oral to the first anal plate. The anus is placed near the upper end, and faces laterally.

Disfribxtl'in. — This genus occurs in America in the Hamilton, Kinder- hook, and in both divisions of the Burlington group. It survived to the Keokuk fiToup, where it is represented by only a single species. In Europe it is possibly represented by ■• Actinocriniis" jminiicnais Mliller, from the De-

hatocrinid^e.

471

voninn of the Eifel, and there is another Hpecies at Colle, Spain, at a horizon whicii is generally recognized as Upper Devonian.

7,V/;e of ihe genus : Aurocrbuts iimaaturus W. and Sp.

liemiirks. — The species for which we propose the genus were referred lieretofore by us and others to Dorijvnnm, except Aorocriiiits Casstihtiji which had been placed under Gciimeocrbuis. It approaches Dorycriuns, difl'ering from it, however, in having single arms, and in not having the long spines upon which Eoemer principally formulated his genus.

Aorucrinus precedes Dori/criiius in time, and has essentially the charocter- istics of an iuuiuiture Borz/crinas. The peculiarities of that genus are ftre- shadowed, but have not acquired their full development.

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Aorocrinus immaturus w. and Sr.

riafe XL V. Figs. 4,1, b.

1S90. Dort/rriniii iiauialui-iis — W. niul Si". ; Clcol. Ucp. lUiuois, Vol. Vlll., p. 175, Plate 16, Fig. 5, ami

riiitu 17, I'ife's. Oaiid 17. IbOO. f>t,}yiriiiua immaturus — S. A. JIiLLCB ; N. Aiiicr. Gt'ol. niul I'lilrcniit., p. 210, Fig. 290.

Below medium size; crown measuring from 30 to 40 mm.; lieight of calyx from 10 to 14, by 10 to 12 wide. I)or.'<al cnp higher than the ventral disk, gradually spreading to the arm bases, the sides a little convex. Teg- men depressed conical, crowned with a subcentral clongjite node or ."hort spine. Plates of the dor.'ial cup moderately convex, their surface more or less rugose, the suture lines distinctly grooved. Color of specimens rather dark.

Bas.als short, .somewhat projecting beyond the colunm, their lower ends bonding abruptly inwaril and forming a well defined concavity-. Eadials large, almost as wide as long, the lower margin but .slightly convex, the upper face concave in the middle and truncated at the outer sides. Cos- tals very short, and not much more than half the width of the radials; the first quadrangular ; the second pentangular. Distichals 2X2, in form re- sembling the radials, but only half their size. In some specimens all the second distichals are axillary and support palmars, in others those of the anterior ray support the arms, which vary in number from eighteen to twenty. Arms stout, single, bi.^erial, and arranged in groups, the tips incurving and flattened ; the interspaces between the rays deeper than those between their subdivision.s, and in the anal interradius nearly three

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472

TIIK CKIXOIDKA CAMKR.VTA OK XOKTII A.MKIUCA.

times ti.s wide. Interbracliiiils three ; tlio first very large, ns wiile as higli. tlio two upper quite suiall. Tliey are followed by two still suialler pieces, which are on a level with the arm bases, and these by ecjually small inter- umbulacral plates; there being no interdistichals in the dorsal cup, but several in the tegmen between tiie ambulacra. First anal plate much longer than the radial-i, and the largest plate of the dorsal cup. It is (bllowcd by three or four higher aiials, longitudinally arranged, which dccroa.sc rapidly in size upward, each one having an interbrachial at the sides. Tiiere are numerous j)lates idjove, which form a longitudinal I'idge with a deep sulcus at each side. The anus, wiiich is placed at the upper end of this ridge, opens out laterally. Orals a little nmrc convex than any of the other plates of the tegmen ; tiie posterior one very large, its size equal to that of two of the otiiers and generally extended into a short spine. Food grooves covered liy a few alternately arranged medium-sized i)lates, which are more prominent than the interambulacrais, especially on approaching the arms. Colunni com- paratively short, gradually tapering, and terminating as a fine thread ; its whole length being from 7 to 9 cm. The joints throughout arc moderately long, and increase in length downward. The}' are in the upper part of the stem distinctly rounded at their margins, and project conspicuously over the younger joints; but at the lower part cylindrical and of equal width, giving off toward the end at irregular intervals, and at different sides, rather stout and long cirri.

llor'aoii and LocnUtj. — Kindcrhook group; Le Grand, Marshall Co., Iowa.

2]'/pc!i in the collection of Wachsmuth and Springer.

Aorocrinus radiatus w. ami Sp.

Pkdc XLV. FIff. 1.

1S90. naryrriiiiis raiVutliis— \\. niul Sp. ; GcnI. Hop. Illinois, Vol. Vtll., p. ]7fi, Plnte 17, Figs. 5, Grt. IStlO. Ihr^criiiun rw/iii/iif S. A. Mii.i.K.ll-, N. Amor. GocjI. niiil l'aln?oiit , p. 210.

Resembling the preceding species, but having a different arm formula, and radiating ridges upon the plates. From the radials two low, rounded ridges pa.ss out to the basals, two to adjoining radials and the first anal plate, and one to the first interbrachials. The latter plates have nine ridges, two meet- ing with those from the radials, the others, which are somewhat smaller, with the costals and the interbrachials of the second range. The ridges are well

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BATOCniNIP.TJ.

473

defined next to the margin of tlic plates, but are indistinct, or disappear altogether, in the middle portions. Color of specimens lighter tlum in the lust species. Tlio culyx up to the arm regions ia obconicul, wider than high, and a little convex at the sides.

Basal cup short, projecting laterally, and forming a rim which is slightly oxeaviited at the bottom. Radials somewhat shorter than those of Aoro- rriiiii.i iiiiniati(ri(s, the costals proportionally longer. The distichals vary in number; in the anterior ray there are 2X2 in the calyx, followed by free arm plates; the other rays have two in one division, but only om" in the other, which is axillary and followed by palinars ; exceptionally in the posterior rays the first is axillary in both divisions, but generally only that next to the anal side. Arms fourteen, rather stout, rounded on the back, and quite long ; they are composed of two or three cuneate plates, which interlock and are followed by two series of transverse pieces, united by parallel sutures. Interbrachials six in three ranges ; the first plate is large and extends to the top of the costals. There are three much smaller plates in the second range, and two in the third, the latter on a Icvol with the arms. Anal area very wide, the first plate as large as the radials, the three succeeding plates fully equal in size to the single plate at the four regular sides, the middle plate being a little the largest. These plates are followed by numerous smaller ones, which take part in the ventral disk. Construction of the tegmen and position of the anus unknown. Of the column nearly throe inches are preserved in one of the specimens ; it is de- cidedly tapering, tiio nodal joints high and projecting. So far as observed, the stem changes but little its general habitus. As it decreases downward in width, the intcrnodal joints retain nearly the same proportions to the adjoining nodal ones as close to the calyx.

Horizon ami LocaVitij. — Same as last.

Ty^cs in the collection of Wachsmuth and Springer.

Aoroorinus parvibasis w. and Sp, Plate XLV. Figs. 3a, h.

ISOO. Dor^miiiia /uirriUm — W. mid Si>. ; Geol. Rpp. Illinois, Vol. VTII., p, 177, Plate 17, Figs. 7 niul

9, <Jrt. 1S90. DoryrriiiHa pareihasis — S. A. ^^lLI.En; N. Amor. Gcol. niid Pnlreont., p. 2tO.

A small species, Calyx oblate-spheroidal, excavated at the bottom. Dorsal cup in form of a basin that rests upon the basals and portions of

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474

lUK CRINOIDKA CAMEIIATA OK NOUTII AMKKICA.

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till' rttdials ; witlor tliiin high, and .Mproading but little at tlio sidcH. Platos iiioderatuly convi'x, witliout ornamentation ; suture lines well defined, with a small pit at each angle of the plates. Color of specimens ns in -^1. wmutlurus.

Basals forming a disk, which rcMts within a shallow concavity formed by the united radials, and not visible in a side view. Radials large, heiitagonal, narrow below and wide above, the lower end curving inward. C'ostals small, nearly of equal size. Distichals unevenly distributed among the rays, the three anterior rays hiuing from tsvo to three in the calyx, which nre fol- lowed by free arm plates; the two posterior rays, in the division next to the anal side, but one, which is axillary and followed by two fixed palniars; the opposite side having three distichals, thus making fourteen arms to the species. Arms arranged in groups, the space between the posterior rays much the widest; they are quite robust, tapering at the end, rounded, and biserial except one or two cuneato pieces at the base. Interbrachials in two ranges; the first very large, reaching the top of the costals, and touching the distichals. the others small, resting between the distichals. A third range is on a level with the arm bases, and followed in four of the areas by four to five intcrandjulacrals. Anal area very wide, elevated along the median line, deeply grooved at each side, so as to form from the distichals to the posterior oral a longitudinal ridge, which is most prominent in the upper part around the anus. First anal plate larger than the radial.^, longer than wide ; the second, and the interbrachials at the sides, as large as the corresponding single plate of the other areas ; the plates above small and irregular in their arrangement. Tegmen depressed convex. Orals large ; the posterior one extended into a thick, elongate node, and twice as large as the others, which are moderately convex. Anal opening directed laterally. The food grooves and their branches, respectively, are covered by a single plate. The stem apparently was longer than in the two preceding species, and less taper- ing. The nodal joints are a little wider than the intervening ones, which increase very rapidly in nuinljer, there being six to the internode at an inch from the calyx, which appears to be the maximum number.

Horizon and Locah't//. — Same as last.

Ty^'cs in the collection of Wachsmuth and Springer.

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^;

BATOcmxin.ic,

470

Aoroorinus oanalioulatus (^r. ami w.). Piute XL V. Fi^js. Oil, h.

I'iflO, Diiri/tTiiiiit camilirithiliit — IFkkk nnd Woiitiikx ; I'ldcccil. Anid. Nut. Sri. Tliiln., p. 105.

1S73. Vorj/criiiin cuiKilintUitu' — Mekk ami AVokthe.n ; (ii'ol. Ilcp. ]|liiu;is, Vul. V., p. 3sl, rhilc 0,

Fi({. 4. 1881. Doi'i/criiiKK eiiiiiilii'ii/ii/in — W. and Sp. i llevisiuii I'ula'm'r., Fart II., p. ITU (Proceed. Acad. Xnl.

Sci. riiiln., p. 3j.'i).

Calyx below modiuin size, it.s heiylit a little less tlinii the width at tlio arm base.s, the iloi>al cup shorter than the ventfal di.sk ; tlie former witii broadly trimciitcd bottom and moderately spreading sides; the latter de- pressed conical. Plates of the dorsal cup convex, roughened by a peculiar Bhallow pitting, which extends over the entire surface, but is more conspicu- ous around the margins of the larger plates, to which it imparts a slightly crenate appearance ; suture lines deeply canaliculated. The plates of the ventral disk are less convex, but also defined by canaliculated sutures, and roughened by a pitting like that in the dorsal cup.

IJasals extremely small ; only their outer angles visible in a side view ; subhexagonal in outline, with small lateral notches at the sutin'es ; the col- umn facet occupying two thirds tlie depth of the plates. liadials once and a half as wide as long, the extreme lower end bending inward to meet the basals. First costals quadrangular, fully one half smaller than the radinls, and about once and a half as wide as long ; the second quadrangidar and somewhat wider and longer. Distichals 2X2, as wide as the first costals but still shorter. In the posterior rays both upper distichals are axillary, and each one supports two palmars ; in the anterior ray only the one to the right is axillary, the other bears a single arm ; the antero-lateral rays have no palmars in either division, and but two arms. Arm openings arranged in groups with rather wide interspaces, of which that at the anal side is almost three times as wide as the others. Arms si.xtoen. one from each opening ; rather heavy and long, incm-ving, their upper ends flattened and distinctly serrated at the outer edges. Pinnides closeh' packed together; their joints but little longer than wide. First interbrachial almost as large as the ra- dials ; it is followed by two plates in the second, and two in the third range, the latter on a level with the arm bases, and in contact with the interambu- lacral pieces. The first anal plate supports three adf^itional anals in a longi- tudinal row, which rapidly decrease in .size upward, and each one of them is

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470

TllK CUIXOIDKA CAMKHATA OK NOUTIl AXIKltlCA.

placed between tlio two interbmcliials. The platen of tlie vi'iitml disk nrc riitlicr 8tiiiill, tlie pu.storior oral excepted, which is quite hirge, tuberculiforni, and central in position. The anus is placed a little above tlio arm regions; it is surrounded by numerous snudl plates, and opens out laterally. The am- bulacra apparently are roofed by small covering pieces.

Iloi'iziiti Olid Locality. — Lower Biu'lington limestone; Burlington, lowo.

I'l/jic in the Museum of Comparative Zodlogy.

AorocrinuB subaouleatus (Hall). Plate XLV. Fitjs. 7a, h.

ISjS. Ai-liiioi-riiiiii aiihuciiledtui — Hai.l i Gi<il. Hrp. Inwn, Vul. I , Tort II., p. 5*0, Tlntc 10, Figs. 2(/, b. 1S73. Duri/fi-iiiiis sa//iiriileii/iis — Mkkk and WdUTiiKs; (ii'ol. Urp. Illinois, A'ul, V,, p. ;iSO. ISSl. Duri/iviiiiis siiliai'ulivliia — \\. iiiul Sp. ; Itevisidu I'lilicocr., I'lirt II., p. ISii(l'rocicU. Acad. Nnt. Sci. riiila., p. 351).

A small and very rare species. Dorsnl cup symmotricall}' semiglobose ; the tegmen abruptly conical, with nn acute spiniform plate at the top. Plates delicate, Hut (their natural curvature e-Ncepted) and jierfcctly smooth ; the suture linos obscure.

Basals in form of an inverted cup, very smoU, and frequently not visible in a side view. Radiuls almost as long as wide at the upper end, the lower end considerably narrower and bending inward. Both costals together equal to the size of the radials; the first quadrangular, fully twice as wide as long; the second pentangular and wider ns well as longer. Distichals 1x2; these of the posterior rays axillary, and followed by two single very snuill pal- mars. In the antero-lateral rays only that next to the posterior ray is axil- lary', the otiier subquadrangular; the former supporting two .small palmars and two arms, the latter a single arm. The same structure prevails in the anterior ray, in which the distichal to the right supports the two arms. The arm-bearing plates somewhat projecting. Anr cporHngs directed laterally, arranged in groups, the spaces between the rays depressed, that of the anal side deeper and wider. Arms fifteen ; their structure not known. The first anal plate is longer than the radials and full}' ;is wide ; it supports three large plates in the first range, and three much r.inaller ones in the second. The plates above are small and irregularly arranged, forming a flattened area, which extends to the posterior oral. The intcrbrachials of the other areas consist of three plates in the dorsal cup, and two between the arms, which latter in.seusibly connect with the interdistichals. The anus is placed half

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nATOCniXID.K.

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wny between tlic liirj^o oriil niul tlio nrm regions, and opens out laterally.

StruetiMo of nriiis and coliinni not known.

IliirixoH Kiiil Lvntlify. — Lower Hurlington liine«tono ; Burlington, lown,

Ti/j)c in tiic (Wortiien) IllinoiM State collection, S|)ringtiel(l.

lieinarh, — Closely approaeliing AurncriiiKS imrrilmsis, wliieli has a ."iiiii-

Inr ba.so, and resembles it in its general outline ; tliat species, however, has a

very different arm formula, and tlio plates of the calyx are distinctly conve.v.

AoroorlnuB parvus (Sium.). ricttc XL V. Fi,jH. 11a, h.

1955. Ji-tiiiurihiui parvui — Siiumahdj Hep. Geol. Siiiv. Missouri by Swallow, Part II., p, 193, Plntp J,

I'll?, y.

1831. Dori/friiiua piirviit — W . ami Sp. J Revision Pulicocr., I'lirt II., |i. 179 (rrccced. Acad. Nut, Sci. I'hila., p. a,-).1). SjM. .ic/imiiriima s^iiiiiii/ricNi — U\LL, 1858, Geol. Hep. lown, Vol. I., I'art II., p. b7i, Tlule II).

l'"i(,'». 8(/, i. Sjn. /hirfcrimit amiiiiiii— S. A. XlaLEii; 1891, Gcol. Suiv. Missouri by Arthur Wiuslow, Bull. I., p. !i5, I'lute 4, l''i|;s. 5 iiiiil 0.

A small species. Calyx rotund ; tlie dorsal cup higher tlmn the ventral disk, slightly obcoiiical ; the peri[)heral portions abruptly projecting outward, and distinctly lobed ; the interspaces between the ra^'s broadly and deeply excavated, and there are smaller excavations between their main divisions. Plates flat and without morkings, except an obscure longitudinal ridge upon the costals and distichals.

Ba.sals rather large, forming n broad, shallow cup with a narrow excava- tion nt the bottom. Eadials very large, almost as long as wide ; the trun- cated upper faces a.s wide as the upper face. First costals quadrangular, once and a half as wide as long, the second quadraugidar, smaller than the first. Distichals one or two. All divisions in which palmars are represented have but one distichal, but tho.se in which they are wanting have two. The anterior ray invariably has but two arms, the two posterior ones from three to four, and the antero-lateral rays from two to four, frequently the left having more than the right, or vice trrsa. The number of fixed palmars varies from one to two, and large specimens generally have a small inter- distiehal. Arm openings directed slightly upwards, and arranged in groups of two or one. Arms one froi.i each ambulacral opening in the calyx; they are short, heavy, biserial ; their plates moderately short, and every fourth piece extended into a well defined lateral spine. Interbrachials five to seven:

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•178

Till", (HINOIDKA CAMKHATA OF NORTH AMKHIt'A.

1, 2, '2, '2; tliu two upper on a levi'l with the nnn biisos. I'ostorior urea extroniely wiiU', its niudiun lino roiiiideil Init not riiigod, l""ii>t uiuil plato f'ullowod by tliii'o large pliitCH, and tIll'^^u by tlneo Mniallt'i' onuM, wliicli sn|i- port nuinoi'ouH otiit'is without dednito arrangi'nu'Ut. Tiio jdiitos of Iho logiiUMi arc lliif, t'.\t'i'[it the posterior oral, whirh is slightly ronvex and central in position ; the lour other orals are pushed anteriorly, nnd nro surrounded in largo specimens by irregular perisoniic plates. In snniller spei'iineus, their outer edges abut against a large radial dome plate, from which two rows of covering pieces at both sides pasH out to the arms. Tho nnus h placed halt way between the sinnniit nnd tho arm bases, nnd oj)enn out laterally. Cohunn small; composed near the calyx of wide and narrow joints.

Ilmi:"!! mill l.nnili/i/. — Upper Burlington limestone; Burlington, Iowa, nnd at tho same horizon at .several localities in Missouri nnd Illinois.

Iiiiiiurk^. — The arm formula of this species varies exceedingly. Among seventeen specimens there is one with 1^1 arms, five with 1,1 arms (thi.«i is the arm lormula of " Ai'tiiiorriiiiix" xi/iinin/ririi.i Hall), six with 1^1 (as in S. A. .Miller's Dnri/n-iiiiin amwiiiiti), one witii 3^1, nnd four with ?/' arm.i. A.s a. rule, large .specimens hiivo more arms than smaller oiu's ,ind tho s|)eciinens with ten arin.s are without exception Hinall. The pecimens are identical otherwise, and this proves most conclusively t' .tt the number of arms, in this group at least, cannot bo made a ."specific character imless accompanied by other structural differences. Such, however, do not exist in Dwycrinm aiiianiis Miller, nor in Ac/hwcriniis si/vimctriciis Hall.

Aorocr'nua spinosulus (HM.t). PMc XLIII. Fli/. 4, ami Phk XLIV. F!;/s. Sn, h.

l^^)0. .lrllimcriiiii.1 .yiimniilua — }\.\\,L\ Suppl. ficdl. licp. Ii wn, p. Hi.

li>l. Ih,yiTiiiii.< y/iiiii^xii/iiii — W. nnd Sr. ; licvisidii I'alii'ncr. I'aii II., p. 1^0.

!Svn. I)i,r;i,;i,iiia Kilhyrji— WouTiiKN ; (i(dl. Hi'p. Illinnis, Veil. VI., |i. 513, PImIc 29, Tic. 8.

A small species. Dor.inl cup obconical, strongly lobed nt the arm regions, truncated at the base; ventral di.sk almost flat nnd without spines. Plates devoid of ornamentation, a little convex, the suture lines grooved.

Ba.sds large, forming a cylindrical cup, excavated at tho bottom. Radials very large, longer than wide, the sloping upper faces .«hnrt. First costals hexangular, of more than medium size, one third wider than long. Second

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•1711

coMtiilH pcnf!itr«»nt\l. a h. ilc larger 1 ;) llif fn , their xlopiiig upper facer' in all tlio ni}M niii'poi *'i',g nn axUU disticlml, and tlii.M two Hiiiall pniinnr^ wliicli among tllc•rn^ en, lUitl wit , tlu' two of tlie opponito side of the rn}', are in contact liitcni"/. Ann openings Hniall, four to the ray ; am- - niinplo, very Mliort and delicate. liitoirinlial spaces wide and deeply depie>hi'd between the free rnyf. Kegnlar inteihrachialH 1, 2, 3, dceicafing in cizo upward; the fust not larger than the lirst eostals; the two of the Kcond row Miiinowhat HUialler ; those of tlio third narrow, occupying the (Icpie^ions between the rayH. The inlerhnichials are followed by three or four minute interambnlacrid pieces which meet tho orals. Anal inlerrndius extremely wide, tho interspace at the arm bases twice that of the other inys. There is a vertical row of four anal plates, followed by a nundjer of irregular pieces, which form an almost Hat area and enclose tho anal opening. At each side of tho second anal ]ilate there is a good sized intcrbrachial, and to each side of tho second aro two sniidler pieces. Orals large, occupying fidly one half tho surface of tho disk ; they aro convex, sometimes conical but not spin- ous; the posterior one is a little larger than tho four othorH and pushed in between them, but, as a rule, tho onds of this species arc more symmetri- cally arranged and proportionally larger than usual in this genus. The primary radial dome plates rcsoinblo tho orals in form and size, and occupy the outer end of tho lobes. Anal opening directed laterally, and placed almost on a level with tho arm bases.

Ilvr'izon (111(1 fjiicii/iti/, — Keokuk group, Keokuk, Iowa, and Nauvoo, Ills.

T//])e in tho (Worthen) Illinois State collection, Springfield.

licDiarf,'": — Wo regard Dorycn'niis KeUoggi Worthen as identical with this specie.", from which it was said to differ in the number of arms. That species was described as having but three arms in one of tho antero-latcral ray.«, a structure which clearly indicates an irregular development of the rn3'.s.

Aorocrinus sjiliiovilus is closely related to A. pamis Shum. from the Burlington group, and its structure indicates that it is a descendant of that species, but sufFiciently differentiated to be ranked as a good variety, if not as a full species.

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480 TIIK CUIXOIDK.V lAMKUAlA Ul" NOIMII AMIOUICA.

Aoroorinua elegana {>^. A. Mut.^n).

j'liik xxsiy. j'i.js. j;,i,b.

)S99. thrii,-rini(trl,yilHil — i. A. Mll.l.rili Ailv. Slii'cll ISlli U, p. (i,' Vi^t. I mid J.

8iir». Iiiiliim», p. 17, rinli' 3,

A iiiii(1omtoIy himiiH Hpocics, calyx obconoidiil, ns wide iim lii^jli, flu^ bnno tnincalcil, tliu Nidos aliiioHt Ntraiglit, mid not groovod butwui'ii tliu vny*, I'xci'pt tlio anal nido wliicli lias ii dopii's.sidii at the arm it^rioiiH. 'J'lio platL'H slightly convex but without oniauK'ntutioii ; tho Buturc lines Hunie- what channeled.

Basal cup ratlier hi^li, Nubcylirnliical, the inteibasal nnturcN slightly notcluMl at the bottom; tho culiuiin facet deeply depicsed, and occupying Inilf the diameter of the cup at the U)wer end. Hadi.ils ii little upreading, larger than both ccstals together, and geniMally an long as wide, their lateral faces longer than tho upper. CostalH Nmall, variable in Ibrm nnd »<i/.c, xome of them ([uitc narrow and almost m long an wide, oihi'rs almost twice as wide ns long; the first (|UMdrangular, the second pentangular, hcNangidar or heptan- gular, owing to the height of the adjoining first interbrachial. Distiehals two, as large ns tho rostals and of similar form, Palmars but one row in the calyx. Arms fom* to tho ray; their structure not observed, but they evi- dently were simple, to judge fiom the arm openings, h'egular interl)rachi- als three ; the first rather largo, and about as high as wide; (he two of the second row less than half tho si/.e of the first, nnd one of them generally a little larger than tho other, both separated from the jjlatos of the disk by the palmars, which meet above. Anal plate of the size of tho radials ; followed by three [)lates, which are almost as large as the first interbrachial of the regular sides. There are throe smaller plates in the third row, and these uro succeeded by a very large elongate plato, which forms tho bottom of tho depression nt tho nrm regions. Ventral disk very slightly convex, almost Hat, and composed of but few large plates. The orals decidedly nsynnnetrical in their nrrnngement, the two postero-lateral ones forming a straiglit line with the posterior one ; they are very largo nnd occupy almost one half of the disk. The ambidacra represented by one large plate, followed by two somewhat smaller ones of a secondary order. The inter- ambulacral plates consist of only two very narrow, elongate pieces. Amis subcentral, in (dose pro.ximity to the posterior oral, directed upwards, and placed in the centre of a short protuberance.

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Jliiihim mil) /.iinilifi/. rpiKT nmliiij^toii Ilimwlono, neiir Sutlulia, Mo.

I'l/l'i: ill till) collurtioii 1)1' Mr. F. A. ^<uiii[).ti)ii, Soiliiliii.

JliniurLi. — Tlio ulxiiiiiciil funii uf tlio cu[i, luid tlu- nlmoi*t Hut tlixk, nro tliu Ifiiiling I'lmiactt'i'M uf tliiH KpueiuN, in wliicli it appruiiclioM A, n/iiiiomiliDi Hull. Ilowovor, llio ciilvx ui' tliut H|ii'cii'M in (lc(|ilv jri'iovt'il iit all Mvh, ami tli(t I'liys an* Ht'|)ai'aU!il liy iitiiiit>i'uu.>i iiitciiiraciiial phitcs wliicli paxM u[) lu tiiu plaluH uf tliu iliitk.

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AoroorimiB hoUoe (H.\mV /'/,//, .VAI'. riijs. J mills.

IMt. jtfliiiwfiiim hrli,-r—\\\\.t\ I71I1 llcp N'. V. .Slulc Ciili, Nut. IIi»t., p. .11. IS/S. .I'/i/i.H-riiiMt irii,;'— IIai.i.j (m.,!. ^^,l|■\, Oliiii, I'nlncnl , \ ..1. II., p. lii:i, I'luti' 11, Fi|f'<. 15 !n S. ISSl, .lj.irii;i,;-i,iin ir/if,'— W. i\w\ Sv.; l(i'\i»iciii I'lilimcr , I'liil II,, |). 1 IJ (I'roci'iil. Acml Nul. Sci. I'hilii. |i. iiSIl) 8)11. ,/.7//(mYi//«j ^'■/(.v, viir, c/ii IIm.i.i (inil, Siirv. Oliii., ralniiiil,, Vul II,, y Idl, l'li,ii' II,

Fin*. U III |a. Rjll. Jjiirii-orriiiHi rrii — W. niul Si', ; ISsj, Hi'vlsluii I'lilirnrr,, I'lirl II.. |i 112,

A|>proMeliiii;; in the form of the calyx, and tlic Htoutnoss of its nririH, somi! of tJK' alii'rraiit .'<iriallur forms of Ai/dririivniiuK. Calyx wider than high, till.'. simuiiit crowneil with an don^ato node or Mhort spine. iJor.xal eiip short, rapiilly .spreading to the arm ha.ses, roimded at the liottom, the lower margin.^ vM' the radials liending inward and takin>i' part in the trnncatinn at the hc'toin. Surface of plates nodose, the radial ones transversely anj^nlar, • he ill crrailial ones with obscure radiiitin^r ridges along the margins.

Ua.sids small, arranged almost horizontally ; only small portions of them heing exposed in a side view; the interlmsal sutures deeply cliamieh d at tho lower end. Hadials large, rapidly spreading >ipwnrds; the upper face slightly notidiod at tho sides. First and second costals together smaller than the radials; the (irst quadrangular, the second pentangular. I)i>ti(hals short, consisting in tho anterior ray of three rows of plates in the calyx, of which those of the first row are somewhat larger than the two of the suc- ceeding ones, the latter lieing as short as tho free hrachials ahove. and like lliem rounded on the hack. In tho posterior rays hoth first distichals are axillary, and siipjiort from each side two short fixed palmars. In tho two antero-latcral rays normally the distichals next to tho po.storior rays are axillary and support palmars, the others are followed liy other distichals; it occurs, however, also that none of them are axilhuT or hoth of them ; the number of anus thus varying from twelve to .sixteen. Anns rounded on

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TlIK CIMNOIDK.V CAMKUATA dl' NOIMII AMKHK'A.

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tlio 1)!U'U. Very stuii(. widest al midway, soiiicwiiat laporiiig at Imth oiid.s, tlio tips iiil'oidiiiy. Till' i'lvo arm plates are elevati'(l in tiie centre, and produeed into tiiuisvei'se angular ridges, winidi in tiie npper j)art. of the arm are broken into nodes. Tliere is but a single interi>raeidal at liie regular sides; tlio anal side has two, whieli enclose a second anal. The lli'st anal is a little longer than the radials. The exact arrangement of the plates in the teginen cannot be accurately ascertained from any ol' the specimens. Culumn com- paratively strong; the nodal joints a little highest and widest, and romided at their edges.

/A'/O'/f (iiiil Loc(ili/i/. — Waverly sandstone; Richfield. Sninniit Co., anil Hoyallou. Cuyahoga Co.. Ohio. ( Fig. 2 is made after Hall, Fig. 5 drawn from a gutta percha cast made in a natural mould.)

Aorocrinus concavus (Mi^kk anil Wuktukn). ri,(ti' XLll. F!<ix. J.la, h. c.

ISfil. Ji'lhioi-riiiKu {.tmi'huriiniiiiis) .■mwiiviis — .\li;i:K und WdiiTiii'.N' ; rrooccd. Acail. Niil. Si'i. I'liiln.,

p. i;i-.'.

l*^t).'i. ^li'tiniHTiiui^ (Sji/i,rriK-riiiiis) ri>/iriini.i - M. and \V. ; iliid., p 15 t, ISl'i.'j. Jiiimit'riitiia {(''/lin'ritt/f-) roia'trvus — .M. iind W. ; iliid , p. i.'7>l.

iMili. <■'//».■-•///«.« ,W),v/rM—.\l. niui W; (i.'nl. H,p. Illiiinis V..1. 11., p. i];,, IM.ilc ir., I'iL'-. lil,(, /,. ,: ]S^[. Ihi-i/rriinm I'liih-iifiis — \\'. anil Sr. ; HcviMoii I'ala'm'i-., fail 11, p. 17',l (I'mi'iTd, Acad. Nat. Si'i. ' I'lnla , p. ;i.-i:i).

A small species. Caly.\ siibglobose, wider than high ; the ventral disk aiiiio-t Hat. The sides of tlie dorsal cup rise nearly vertically from the middle of the radials to the arm regions; the lower half curving abruptly inward, and fiu'ining with the basals the bottom of the cup. The plates are nearly Hat and devoid of ornamentation.

r)a>als small, s|U'eading almost horizontally, and forming a shallow in- verted basin, which is slightly notched al the sut tires, h'adial.s extremely large, fully twice the size of both costals together. Costals very small, ipiad- rangular and jientaiignlar. Distichals 1x2, supporting the arms, except in the ]iosleri()r rays, in which the divisions next to the anal area sui)port pal- mars, and tliere are three arms to the ray in place of two in the other.s. Ann openings small, directed outward; the structure of the arms not known. The interbrachials consist of one large iilate ami two smaller ones, the latter being on a level with the arm bases. First anal larger tluin the radials; followed by three rows of tliree plates each, wiiicli decrease in size npwnrds, and connect with the anal opening. Togineu very short, a little depressed

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at tlio iiiiiil .side, and composed of litit few, rallior largo pioces, among wliicli tlio oralrt aio well delliit!(l. Tlie jtostorior oral is coiitial, larger lliaii (lio •siirroimiliiig ouch, and more convex. The anus open.s ont olilitpiely upwards.

l[orir.tia and Loridi/i/. — Lower Burlington limestone ; liurlington, Iowa.

7//y".' ill the Museum of Comparative Zoology.

Jitiii^ir/iii. — Tliis .specie.s i.s readily distinguished fiom allied forms liy llie concavity of the hasal.s, the eurvatin-e and extremely large si/e of the radials, the vertical position of the lixed brachials, and the flatness of the tegmen. It was at (Irst referred hy Meek and Worthen to AiiijilionnTiiiiis, but they afterwards regarded it as tlie tjpo of a new genus, for wliieh they proposed tlie name iSji/idrucriiutu, which, being preoccupied by IJoemer, wa.s changed into Cuclocrimifi.

Aorocrinus Cassodayi (Iaon).

rinh- XLir. F/./s. ll„, b, uml 12.

ISdn. .I.'fiimrniiii.i r.KWrt/// — 1a-on ; I'nim'il. Ai'iiil. N:il. Sci. IMiilii., p. tin, ri.-ilc 1, I'i^-s H, ;!,i. ISSl. (ii'nthroi-riint:t Cusxru/iii/i — \\\ ;int1 Si*.; liovisioii I'.-iIu'itcr., I'iirl It., p. I'il.

(y) Svn. Arliiiiiiriiiii.i i;in/irii/iis — IIai.i, ; l,'illi lirp. N. V. Sliitc C:il). Niil. Hist., |i. I'M.

(y) Syil. Ji'/if/orri/tna i'tt{'/jtMi — 1I.\1,I,; il)i(l., p. IIJU.

Calyx small, width across the arm bases slightly exceeding the height, broad at tlie bottom, constricted at the basi-radial sutures ; thi> interradiid spaces deeply indented at the arm regions, especially at the anal side, which gives to the distichals and palmars the appearaiu'e of arm plates. Plates of the dorsal cup strongly convex, the surface covered with radiating ridges. whicli enter oul_y the margin of the plates.

Hasals large, short, forming a broad rim with .sharp marginal edges, which are notched at the sutures ; the lower face a little concave, and tlie medi.iii part somewhat cxcaviited for the reception of the colmmi. Kiulials com- paratively large, but smaller lliaii the basals ; wider than long. First eostals about half the size of the radials ; the second generally smaller tliiin the lirst. Disiichals 12 X 10, the upper axillary and followed by two rows of palmars ; the latter, as well as the disticlials, curved like arm plates, and projecting cou- spicuoiisly over the iutorradial spaces. Arms twenty, four to each ray. In- terbraciiials four to six ; two in the second row. two or three in the tliiid, ami two between the arms, the latter connecting with the interand)idacral pieces. An.il interradiiis considerably wider; the first tiual followed by three plates, all somewhat smaller than the fir.st interbrachial of the other sides; and these by a l;irg(! number of minute, irregular pieces, forming a rounded, almost

484

THE CRINOIDKA CAMERATA OF XOU'l'II AMERICA.

vortical I'iilge, wliiclj extemls ivbove tlie arm region.", enclosing the nnnl opening, wliicli is diroctoil liiterally. Interdisticlml ><i)aces deeply grooved, and occupied by a single minute piece. Ventral disli low, slightly convex, pentangidar in outline. The ambulacra are tegminal and raised above the general level of the disk ; the food grooves covered by two rows of compara- tively stout pieces with a large nodose plate above eacii bifurcation. Pos- terior oral proportionally large, extended into an elongate node; the four others barely convex. Column small; the axiul canal minute.

Horizon and Localihj. — Hamilton group ; Louisville, Ky., Clark Co., Ind., and Alpina, Mich.

Ti/i>cs in the Knapp collection at New Providence, Ind.

liciiiarks. — From Hall's descriptions it seems to lis probable that his Actiii'wrinit^ raii/iviiliis, A. jirwcun'or, A. pocilliim, and A. cali/pDo, from the Hamilton group of the State of New York, are all or in part identical witii tins species. As neither one of them is figured, and the types in the State Museum of Albany are not accessible to us, we are unable to make the neces- .sary comparison. In 1881 we erronoou.sly placed this species under Ocnnceo- criniis. A subsequent comparison with the types shows clearly that it has essentially the characteristics of Aurocriims,

BARRANDEOCRINUS Anoixin. rialc VIII. Fiij. 1.

1S7S. Axgki.in; Icoiiosr. Clin. Slice, p. 7.

18^5. Vi. auj Sr. ; HovUiou I'lilivocr., I'arl III., p. 135.

The calj'X in perfect specimens is invisible, being completely enveloped by the arms anii pinnules, which hang down over it ; and the specimens, when all the arms are in place, liavc a superficial resemblance to a Blastoid. The calyx is composed of comparatively few plates, and resembles Dori/cvinwi in the form of the dorsal cup, from which it differs essentially in the structure of tegmen and arms.

Hasals three, large. Radials quite irregular in outline ; the posterior ones pentangular, the anterior one hexagonal, and the remaining two hcp- tagonal. Costals two, the axillary very small, subtriangular, its upper angle sharply pointed. Distichals apparently but one in the calyx. Arms ten, very heavy, biserial. folding outward and recumbent over the calyx, cover- ing the latter completely, and leaving of the arms only the pinnules exposed

batocrixid^t:.

485

at the outer surface. The piumiles form a longitudinal roll along the sides of each arm; tiiey are closely paci<ed, and their ends infold over the food grooves from the sides. In the fossil state the dorsal surfaces of the jjin- nules are expo.sed to view, but in the living crinoid they evident!}' were capable of straightening out to expose their ventral surfaces, and to open the food groves of the arms to the water. The pinnules are composed of very deep, elongate joints ; they are contiguous at their proximal ends, and so regularly arranged that it appears as if they might have been connected laterally for a part of their length, only the upper parts being movable. In- terbrachials one; large ; followed by two smaller ones, which meet with the plates of the disk. The anal plate rests upon two basals; it is nine-sided, and succeeded by three and two plates. Of the construction of the tegmen very little is known, it being generally concealed by the lower pinnules ; but from appearances it was composed of large, subspinous oral.i, as^'mmetrically arranged, which alternated with five similar plates evidently representing radial dome plates. Anus cxcentric, opening directly through the disk. Column stout, circular.

Dixtrlhiitlon. — Restricted to the Upper Silurian, and hitherto recoL;ni/oJ only in Gotland, Sweden.

Ti/pc of the genus : Jjiirrutukucrhius srrpfnnn Angclin.

licmar/is. — Throusfh the kindness of Dr. 0. Lindstriim and the scrcat skill and intelligence of Mr. Liljevall, we were enabled tc procure a series of draw- ings made from specimens in the National Museum at Stockholm, by means of which the details of structure of this extraordinary Crinoid are .><hown very completely. (Plate VIII., Fig 1.) Although superficially presenting uui(iuo characters, it is a true Batocrinoid. and we find no nccessit}' of recognizing for this genus a distinct family. The recumbent arm feature is found among the Ilexacrinidie, and also in one specie^ of the AcrocrinidaJ, in whiili it is as marked a character as in BurfaiKfenrriiiiis. but in Arrocriniis and the other forms with recumbent ar!ns — except BunaiHh'nrrlnus — the pinnules are stretched out, and their rentral surfaces are exposed instead of being folded over the ventral surface of the arm.

Our generic description was made to agree with the Swedi.sh form, and may have to be slightly modified should additional species be discovered hereafter. It is possible that the specimen figured and described bv S. A. Miller in the 18th Report of the Indiana Geological Survey, p. 31, Plate 5, Figs. 13 and 14, under Ci/licocrbuis caiialicidulus may belong to this genus.

H

•ISO

THE CRINOIUEA CAMKRATA OF NORTH AMERICA.

Wf liiive not seen the type specimens, anil neitlier Miller's figures nor his description enable us to make a satisfactory comparison. 11' it should prove to be the t^'pe of a new genus, the proposed name Cijlkocrtnnii cannot be used for that form, as it was preoccupied in ISoo b}' Joh. M'uller for a Devonian genu.s. Miilh r made the name " CuUcocniuis," which has the same derivation as Ci/liwcrinus.

AGARICOCRINUS (Tkoosi) Half..

1S50. TiinnsT ; List, Crin. Ti'ini. (I'rncccd. Amor. Ass. Adv. Sci.), p. flO.

18.JS. ll.tl.L (Siilii-c'iiiis ol' .le/iimrriiiii-); Gccil. lii'p. luwii, Vol. 1., I'iiil II., p. ,^00.

ISCil. IIai.i, (Siilii-'c'ims (pf ./«//,//u/-(m-/«n.«) ; llosldii Jouni. Niil. ll.sl., Viil. VI I, p. 2S0.

ISOO. Mkek nml AVohtiii;s (SiilifjciMis of .tiiiiwcriiiiis) ; ficcil. Ui-p. Illiiuiis, Vol. II., p. 210.

lS7a. -MtKi; ;cii,l WuHTiiKN (Slll)^r,Miils (if ./«//</((/r(/cci«u.<) ; iliij., Vul. V., p. W.i.

1879. ZlTThi. (Suliiicnus n! .luip/ionn'riuiix) ; lliuidli. dcr i'liln'cinl., Vid. I., p. .'i"l.

18S1. W. and Sr. ; Kovisiuu I'ldu'ncr., rail 11., p. lO'J (I'rucml. Acad. Kal. Sci. I'lida., p. 283).

CalyK conical or depressed globose ; the lower face concave, flat or broadly convex. Basals three, small, arranged horizontally, and forming a hexagon, which is partly covered by the colunni. Radials rather small. First costals quiidrangidar, rarely hexangular; the second pentangular or hexangular according to the height of the interbrachials. Size of the second costals and first distichals extremely variable, sometimes the former being the largest plates of the calyx, and sometimes the latter. Arms two to four to the ray ; the arm facets of the same ray contiguous, but each arm having a sep- arate ambulacral opening; tiie arm bases of adjoining raj's separated Ij}' interbrachials. The earlier species have two arms to the ray, but most of the later ones three — some of them four — in the posterior rays, and two in the others. When there are but two arms, the first distichals are followed by a moderately short, somewhat cuneate second plate, which bends inward like an arm plate, and this again by two rows of short, heavy arm plates, of which the proximal one, and frequeni,ly those of tlie two succeeding rows, are in contact with their fellows of adjoining arms. The arm plates inter- lock with those of the opposite row, and the inner ones with the proximal distichals, wluch are ni.<o alternately arranged among themselves. Arms long and ponderous, heaviest at their bases, whence they taper gradually to the tips. Interbrachials tin-ee or more ; in size as variable as the costals and distichals, but all of them narrow and long. In some species the first plate rises almost to a level with the arm bases, in others only to the middle of the first costals, and in this case the two plates of the second range are

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I

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extremely long. First niml considenibly longer than the rnduilH, nntl much narrower at the upper end ; it supports an elongate second anal, and at each side a large interbrachial ; the sue(X'eding plates are much smaller, and form a more or less protuberant area, which extends to the posterior oral, and contains the anus, which opens out laterally. Ventral disk conical or hemi- spherical, the interradial spaces somewhat depressed. Oral |)latos large and prominent; the posterior one larger than the other lour, aii. central, cither in contact with the latter, or separated from them by small perisomic {dates. The food grooves covered by superimposed interamliulacrals, and toward the margin of the togmen by one or more large radial plates. Column long, composed of large and smaller pieces ; the axial canal rather small and pentalobate.

Distribiilion. — Known only from the Mississippi A'alley, where it occurs in both Burlington beds, and also in the Keokuk group.

7}/j>c of the genus: Aijitrimcrlnitx (DncricniuiK.

Eciiiarli.i. — This genus is most remarkable for the depression of the dorsal cup, of which in the typical form only the arm faci'ts and portions of the interbrachials cnn be seen in a side view, the lower parts being flat or more or less concave. Another good character is furnished by the disticiials, whicii, taking the form of arm plates, curve inward and interlock with one another; and last but not least, by the ponderous, gradually tapering, biserial arms, and the elongate form of the interbrachials. In all of these Aijaricnrrhiiis dillers essentially from Aorncrinus and Don/rrinxs, with whicli it has certain adhiities. It has been most frequently' confounded with Am/iJiorarriiiii,s, to which in some species it has a superficial resemblance in the form of the calyx ; but the arm structure and position of the anus in the two genera are different, and, in the typical forms, Ainphoracrlwoi has only two plates in the row above the anal plate. For specific separation we rely upon the variations in the proportions of the interbi'achial plates, and the form and size of the costals and disticiials. as the best distinctive char- acters. The nundjcr and distribution of the arms, the form of the anal area, and the condition of the oral plates, are also important.

i 4

488 TlIK Cia>OIUi;A CAMKKAIA Of XOKTII AMEIUCA

Agaricocrinus Americanus (i!<ih:Mi:ii>. riule XLII. I'ii/s. 1, J,i, b.

1855. Jmphofarriniii amfriciiiiii.i — lioiMiii ; Li'lhira Cit'iij^u. (Aiisj;. li), p. 250, I'liiti i ., Figs. 15«, i. ISlij. ,l'/iirinifriiiii.< iiuiirifiiiiu' — Siii MviiD; 'riiiiis. Aciiil. Si'i., Si. I.iiiiis, Vnl. II., |i. 351. 1*>S1. Ji/iini'ofriiiiii iiiiifrifiiiiiiii — \V. iuul Si'. ; Kuvisicpii I'lilii'iicr., I'arl 11, p. III.

(Nul Auiii/iurcii-riiuix «///c/7'i«//«.i(,lii;.vsTi.i>T, lliiiiilb. del' rilnliichnikuiiiU' [.\i'll. H], p. 95", I'liito 77,

I'is^. 7^^^ 'ti/iiririH-riiiHn U'lrt/hni Il.'ill.) Sj'ii. .1i/(irii\ ./•iiiiia ilhjiiiiilia S. A, .MiLLtiij AJv. Siiui'ls 17lli Ucp. Ciuol. Survey liuliuiin, p. 55, riate S, I'ij;, U.

Ciilyx hoiuispliorical, moiv or les.s deeply excnvateil nt tlio bottom. The upper Imlf of tlie interbniehials anil the arm facets are the only part.s of the ilor.siil imp visible from a side view ; the bai^als, radials, and costids occupy the basal concavity, and the distichals and palmars stand more or less at right angles to the vertical axis of the calyx. All plates of the dorsal cup siiow a slight tendency to become convex, and the suture lines are moder- ately distinct.

BasaLs very small, and covered completely by the upper stem joint. Radial.s small, very little larger thnn the lirst costals; their extreme lower edges bending abruptly inward to form the concave base. First costals ({uadrangiilar with convex sides. Second costai.^ and first distichals larger than the radials, and their surilice generally somewhat more convex than that of tiie plates lielow. The first distichal of the three anterior rays, in wiiicli there iire two arms, is followed by a cuneate second, which interlocks with the first, and with the three lower r.rni plates of the inner rows. In (he two posterior rays, wliich have three arms — exceptionally four — the divisions next to the anal side have but one distichal and two palmars. Arms heavy at the base, but tapering all the w.ay up to the tips, where they end in a sharp point. They arc composed of two rows of short joints, with .xlightly convex outer faces, which give off ratiier stout and long pinnules. Interradial spaces somewhat depressed at the arm bases; the anal side very much the widest. First anal plate longer than the radials, and longer than wide ; it is followed by a .second anal and two interbrachials, one nt each side, the latter rising almost to a level with the arm bases, and beyond the upper end of the second anal. The next row generally eonsi.sts of two short plates, which are succeeded by numerous small, irregularly arranged, convex pieces, which form a large, abruptly protruding lateral anal protuberance, with the opening in the middle. First interbrachial of the regular sides

i.

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HATOClfIN'lI).T,

4SU

narrow iiiul vovy long, riirviii^i? abruptly from the Imsiil concnvity to the iil)per edj^c ol" tlio dorsiil cup, (lii'ii tiipcring iiml rising somewiuit Ix-yoiul tlic soconil iiiterbniciiial.s wliicli lie at liotli sides of it; tlio latter Ibriiiing cxtrcintly iiarmw strips, nliich rust against the curved up liiieral faces of the secoiul disticlials. Ventral disk subpyraniidal, the interradial spaces slightly depressed ; plates highly convex, excejit the interambulacral pieces, which are almost Hat and considerably smaller. Surface of the plates finely granulose. The posterior oral, which is as largo ns any two of the others, and slightly* cxcentric in position, is sm-rounded by eight plates: viz., the four smaller orals, two large ainil pieces, and two radial dome plates of almost the same size as the oraN. Near the periphery there is over each ray another largo radial plate, and over the posterior ray toward the nnal side a second smaller one, which is wanting in the rays with two arms. The interam- bulacrals consist of five to six pieces, and two other plates overlie the nndiulacra. Column comparatively narrow ; the nodal joints slightly wider, with convex outer faces.

Honzoii a>ul Loraltti/. — Keokuk group; White's creek, near Nashville, Tenn., and Pilot Knob, near Louisville, Ky.

T>/pe in the Mineralogical .Museum at IJreslan.

ItcmdrJcs. — Tiiis species is remarkable for the extreme length of its first interbrachial pieces, rising as the}' do to the lop of the dorsal cup. and the great tumidity of the anal area, which, together with the form of the calyx, distinguishes it readily from the other species.

In 1878* we placed Aijofwocriiinx hulfn/iin Hall, A. c.rrai'niiia Hall, and A. iKx/iisii-s iMeck anil Worthen as s3nonyms under this species. Since then wc obtained a largo number of additional specimens, especially fioni the typical locality, which show that these forms can be .specifically separated.

Agaricocrinus Americanus, var. tuberosus (Ham.) W. and Sr. Phite XL. Fhj. a, awl Plate XLII. F\,j. Jf.

1<*J0. Tiioost; List ofCriii. Tenn. (I'rocrpd. Am. Ass. Adv. Sci. Ciimtir. >[ccl.. p. fill). 1S50. 1'vt.I,; Gcnl. Rc|). Iowa, Veil. I., I'ait II., p. 017, I'lalc If), I'i^'s. 2-i, //, c.

The specimens for which we propose this variety have been generally regarded as synonymous with A. anicrlcaiuis. A compari.son, however, of

• Proceed. Aciul. Nat. Sci. riiila., p. 210. 62

ll'l

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1 I

490

TIIK CRIN'OIDKA CAMKUATA OK XOUTII A.MKUK'A.

autlu'iitic npuciiiu'iis from Wliitc'.s creek iiuiir Nashville, Teiin., Koeiner's t3piciil locality, with those iVoin lowii ami lllinoiH, which Hall described and liyiired an Af/nrivocrliitoi liilnrosiiti, shows that the latter are sutliciently distinct to be recognized at least as a variety. The two forms resendjie each other in their general outlines, but the lower face of the calyx in the Iowa specimens is considerably more concave ; their Ih'st interbrachials shorter and not visible in a side view, or but very slightly ; the plates of the dorsal cup are somewhat more convex, and the anal area is less tumid, and not so abruptly protruding' as in the typical form of A. aiiuncainia.

Jfiirizoii (iiid Locdliti/. — Keokuk group, Keoknk, Iowa, and at Hamilton, Nauvoo, and Niota, Ills.

I'upcs in the collection of Wachsmnth and Springer.

AgaricocrinuB Wortbeni llvit.. Plate XXXIX. Fi'i/. 0, and P/atc XL. Fi>/s. 5a, h, c, d.

1<!39. Hah.; Gei.l. U(-|i. lown, V.il. I., I'lirt 11., p. Ol'J, IMiile IB, Fi^'. 1.

l'"-'!. W. :iiiil Si'. 1 Uevisiuu l':il;iHK'r., rurt 11., p. 113 (Proccuil. Acad. X:it. Sci. riiiln., p. 2''7).

A largo species. Calyx depressed pyramidal, pentagonal as seen from above or below, the anal side broadly and deeply excavated, and the po.sterior rays distinctly lobed. The plates of the dorsal cup to the middle of the second costals placed within a deep concavity, which contains not only the basals, radials and first costals, but the whole of the first interbrachials and parts of the second. All succeeding jjlates of the dorsal cup are stretched out almost horizontally, and only the arm facets and the third row of inter- brachials are visii)lo in a side view. The plates within the concavity are perfectly fiat; while all radial plates from the second costals up are more or less convex.

Basals slightly projecting beyond the column. Radials noarl}- as long as wide. The first costals fully as large, or even larger than the radials ; hex- agonnl, their upper angles truncated by the second interbrachiiils. Second costals about twice as large as the first ; wider, but not as long. First dis- tichals almost as largo as the upper costals, their width much greater. The second distichals, when represented, are wider than the first, but half their length. The posterior rays, which have three or four arms, have but one distichal in one or both divisions, which supports on each side a rather large palmar, and this, which is formed like an axillary, is followed by the two rows of arm plates. Arms twelve to fourteen, long, stout, tapering ; com-

■f-

nATOCRIXID.E.

•101

posed of two series of ninety or more joints to cacli series. Iiiterlniu'liiiils: 1, 2, 3; the first very short nnil siimll for liie genus, not rising to tiic full height of the first costals; the two of the second row twice as long as the first and very narrow; the plates of the third range quite variable in form and size, and partly interanibnlaeral. First anal plate larger than the radials, and longer than wide ; deeply truncated at the iip[)er angles for the support of two large, elongate interbraehials, which enclose a narrow second anal. There are four to live plates in the next range, which are followed by nume- rous small, irregular pieces, forming a flattened area containing the anus, which is directed obli(|uely upwards; the plates of this area gmw smaller as they approach the anus, which is located midway between the posterior oral and arm regions, and opens out laterally. Ventral di.«k depressed conical ; the orals and radial dome plates large ami covered with heav}' rounded noilcs, which extend over the wlude surface of the plates; the intervening pieces are comparatively small and but .slightly convex. Posterior oral extremely largo, and separated by small peri.somic jilates fiom the other four, and similar plates are interposed between the latter, .«o each oral is isolated. There is one large radial dome plate over each anterior ray, and two over each posterior one, the second jdatc being placed above the division with two arms. Tlie interambulacral plates arc quite numerou.s, and cover over the origin of the ambulacra.

ILir'nnn and Loralifi/. — Upper part of the Keokuk group ; Keokuk, Iowa, and Hamilton, Ills.

'J'i//)c in the (Worthen) Illinois State collection, Springfield.

liemarks, — This species is readily distingni.slied from A. aiurrlrrnnis by its larger si/.e, the hexangular form of the first costals, the different arrange- ment of the interl)rachial pieces, the isolated condition of the orals, and the flatness of the anal area.

M

Agaricocrinus excavatns Hail. Phite XXXIX. Flffs. 3, 4, 5.

ISfll. Affarironinm neavatin — ITat.i. j rrclim. Pcsrr. New Spec. Crin., p. 3. 1S61. A;/iiri'-ncriiiii!! {.tmiihornrriinix) rxrnx'dlim — IIai.i.; Bci^t. Jiiiiru. Xiit. Hist. Vol. VII., p. 2S2. 1S77. Am/j/iorarriiiii.i fjmiva/iis — S. A. Mn.LEIl ; Ciital. .\inpr. I'lilivoz. I'liss,, p. 70. 1393. Agaricocrinm ereuviitaa — WuiTriKLD; Mem. Aiiicr. Miis. Niit. Hist., 1S93, Vol. I., p. 20, Tliilc 2, Figs. It, 10.

Smaller than the two preceding species. Calyx pyramidal, a little wider than high ; the radial portions projecting outward and downward so as to

1^ J

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IW1W"*«^

tl»2

TIIK CniXOlDr.A CAMKUATA OK NOUTII AMI'.IMCA.

[iroiliii'o (li'iiroMsionM at lliu iiituniuliiil s|imH's, IJottom of iln' dorxil I'liii ili'i'iily oxriivatt'il to tlio miiMlo of llio hi'coikI co.xtiilH, tln' distit'lmls lliiw loiiiiinjr tlie liaso upon wliicli \hv calvx ri'sts. All [iImIi's witliin tlio con- cavity- are Hat; while tlio disticlials aio more or less convex, and Honictiinv"* covered willi indiitinet tiansvei'MO angularities.

Ua.iaU .tniall, more deeply depreHsi'd than the snrmnnding platen, mid hidilen tVoni view l>y the eolnnni ; the axial canal moderately small and pent- angular. Itadiids more than twice as wide toward the upper end than at the lower; the lower margins inllected to form the basal eonravity. First eostnls one half wider 'lian long, the upper face wider than the lower; they are quadriiiigular m outline, although frcrpiently one or hoth upper angles are slightly tri'iieated l)y the second interltrachials. Second costals ns largo a.i the radials or larger, .six to eight-sided. Disticlials 2 X 'J, twice as long as the arm iiliiles, interlocking with their fellows of the opposite division, and with the arm plates to the third row. Arms two to the ray, long, very hi'.uy in the lower portions, but gradually tapering until fpiite thin toward the extremities. Tnterhraehials three ; the first comparatively short, often not reaciiiug the top of the first costals ; the two succeeding ones nn- iisuMJiy long and extrcTuely narrow, rising from within the basnl concavity to a lev(d with the arm l)aso.i ; those plates support three elongate, moderately large interaMiliuhu'rals, which are followed by six to eight smaller ones. First anal higher than the brachials; supporting on its sloping npper sides two rather largo interbrachials, and on the middle face an elongate nnal piece ; the next row generaliv consists of four plates, which rise to the heii^ht of the arm bases. \'entral disk depressed pyramidal in its anterior aspect, the posterior side greatly protruding outward and njuvard, and formed into a largo anal process, which rises beyond the top of the posterior oral, and from ■1 lo G mm. above the plane of the ventral di.sk. It is narrower at the bnso than at the upper end, and somewhat depressed aronnd the anus, vhieh opens obliquely upwards. Orals and radial dome plates largo and tuber- culous; till' former in contact laterally; the latter separated from one nn- otlier, and from the orals, by small pori.somic plates. Column small for the size of the species.

ILirixon ami Localihj. — Uppermost; part of the Upper Burlington lime- stone; Burlington, Augusta, and Pleasant Grove, Iowa.

Iinvai'l-!<. — This species is readily distinguished from A. (imcricaiiiis by the very dilTerent size, form, and arrangement of its interbrachial plates,

lUTOCUINin.K.

193

mill tlio more cxtiaviigiiiit form of tlio niml iirotiibemiico. A. Wortfuni in n iinicli larger Kpucics, niul its iiiml nroii lliroii^iioiit in iKTloctly llut.

AgarloocriDUS nodosus Miik luil Wuutiien.

J'lalv XLllI. FIj. 0.

W). Mkkk mul WciiiTiii N I riiii'i'iil. Ai'iiil. Nui. Sci. I'hilii , p. Ifi7.

1S73. MkKK (ma WnUTlUN I (ln,l. ||,p. lllillni., Vcl. V., |i. '.W , I'lllll' 10, I'i(;s 7". «.

riosoly rosoiiiMing ^1. ucurtdiis, anil [lerliniis a mero varicly of lliiit upcpicH. It agrot'M with it in the general Iimim of the ealyx, tiie convexity of the ilor-ial cup, and the form niul arrangement of the ba.xalH anil radialx; the (ir.-<t eostal-i, however, are somewhat shorter, and always (inadianj;iilar owinjf to tlic greati'r length of the (irst interhraeliials; while lia- si'cond eos- tiils for the s;iine reason arc generally oetagmial. The latter platen, like the first interhraeliials, aro larger, and their upper portions, which do not take part in the Im-al concavity, are strongly convex or even nodose. Also the (irst distichids, which next to the axillary eostals constitute the largest plates of the calyx, are decidedly convex, and so to some extent are the inter- Itiaehials of the second row, which aro narrow and rise to a level with the arm ha-es. Second dislichals small and cmicate, not extending out to the full width of the first, the outer ends heing occupied by the succeeding arm [date, whicii meets it from the opposidc side. The posterior rays have toward the anal side hut one distichal, which is axillary, and supports fi'om each side a pidiuar. Arms twelve, not quite as stout as in ..i. (■,((■«- vdtiis, and the anal luocess less protuberant.

TTorhon ntul Lonih'/i/. — Upper part of tiie Ujjpcr Burlington limestono, Pleasant drove, Des Moines Co., Iowa.

T'/pe in tlie Museiun of Com[)iirative Zoiilogy.

nctiHir/,'-i. — This and the preceding species were placed by us in Part IT. of the revision (p. 112) with Ai/nrlcocn'iiKs (uncricaniis. with which they both have close allinitics.

Agarlcocrinus bullatus TTai.l.

r/u/e XLI. Figs. 2(t, b, c, d.

1338. Hai,i,; GpoI. Hep. Town, Vol. I., Vnrt IT., p. 662, Pliite 9, Fi-ra. 11a, *.

Syn. Jt/iirii-iiciiiiiis prnliiiioiiiia — Ham,, ISfiO; Siippl. Gcol. ]{cp. Town, p. 6'! mid '\^'liitfu'Iil, Amor Mus. Nat. Hist. N. York, 189:!, Veil. 1., p. 25, Plate 2, Figs. 17, 18.

Of modiimi size. Cal\'x depressed pyramidal, distinctly pentangular below the arm bases, and rather deeply concave at the bottom. The con-

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404

rilK CUIXOIDKA CAMLUAIA Ol' NolMII A.MMIICA.

■

cikvity in i'ui'iiK'il \)y tliu IjiimiiIm, iiuliiil'*, niid tliu luwiT [tiMliuns nl' tlu' Hr.«t liiterlinieliiaU, wliiclniru xtivtclii'il (uil li()ii/.iiiilally, ami 101111 tliu lial hultoiii 1 tiu! lir.Ht I'o.xtals cuiiititiitt' the hiiK's, wliik* llic m'coikI ('(i.^talH and tliu U|i|ii'i' |i()rtioiH of the iiitei'linicliials dollcct oiilwanl and bliglitly upwaiil, anil I'orni tlio rim u|i()ii wiiiuh tliu caly\ whIh ; tlu* latter |ilut('N iiru 11 littlu uonvux, tlio^o within tliu cunvt'xity uiu Hut. Siittiru Hiiuh well dt'liiiud,

liii'tal't concealed \>y the coliitiin. iindiaU nearlj un long a** ^vidu, the lower margins dcllei'leil to loini the eoliiiiiiiiir de|in>r<sioii. Firnt custalH t|iiMdiiiiigiilai', nearly twice iih widu un long, lieiiding aliiu|itly upwards on tlieir lower margiiiM; tlie .second larger and tliroiigliout wider timii tliu fh'itt, often linger even tliiin tliu radials. Fir.sl disiicliiils «jnile varialile, in ^ome Hpeciniens almost twice iis large us in o(li(i.< ; tliey are succeeded l»y n single ciineate plate, oi' Ity two pieces, tlie edgi? (if the one overlapping the oilier. Arms ten ; contiguous to the third pliili' iiliove the axillary ; Htoiit, but Hliorter tliiin in any of liie preceding species. First interhriicliiids sub- oviite, very largi', soiiieiimes twice as large ns tliu radiiils; they rise to the middle of the lirst disiiclials, where they are followeil by two long, very iiiirrow pieces, wliieli reneb up to the level of the arm openings. The first anal, which is narrower mid higher than the radiiils, supports three large pliites, the middle one narrower than the two outer, and there are three others in the next range. I'osteiior oral somewhat excentric, leaning to the posterior side, very largo and Htrongly iiodoso ; it is sur- rounded by nine or ten plates consisting of the smaller orals, which nro less tumid and of but half its si/.o, two somewhat smaller radial plates, and three to four small, almost Hat, supplementary anal pieces. The nulial plates near the outer margin of the disk are somewhat larger than the smaller orals. Interambulacral }ilates not numerous, there being rurely more tliiin five to each side. Anal area wide and Hat; the anus placed midway between the arm regions and the summit of the posterior oral ; the oiiening directed later.illy. Column very sm..Il compared with the size of the species; joints of nlmost imiforin width ; nxial canal pentangular.

Ifiin'zon and Zonifify. — lTp|)er Burlington limestone ; Burlington, Iowa, nnd at the snmo horizon in Illinois and Missouri.

T'/j)e in the Illinois .State collection at ."springfielJ.

lieniarks. — This species resembles A. Wortfiriii Ilall, in general outlines, nnd has a similar flattened anal urea, but the latter is a much larger species,

<W>

IIAHK llfNID.i;,

40S

lian II ili(Tun>iii nrm fi)niiulii, aii>l tliu oiiiIh arc Hcpnratoil from one ntintliiT \>y

Nliplllctlll'lltdl'}' |)llltUM.

Iliill'M A. /iiii/iiijiiiiiiH iH uii(li)iil)lu(ll,v nvintiivmouH witli thin Hpt'cii'H. Tlio typo Npuuiiiii'ii i^ iiiiii.suiilly liigli mill iiMiiuw, ami tliin iiccuiiiiIm fur the iiiinuwiiusit of iu lir.^t inti-ibmcliiul pluU-it.

AgarioocrinuB splondona s, a, Millrh, J'latr A'A. F>!/n. Ill, b, c.

1S31. a A. Mir.t.Klii Jnurii. riiiciii. Snr. Niil, lli»l., Vul, XIII., I'lMc J, FiK». 1 iiml i ; «l»n 17lli Uiip. Gi'ul. Surv, Iiiiliiuni. p. .'1.1, I'liilr H, Vi^. ID. Sjrii. .(t/iiriiwriiiiis i«r/(./«.«»» H. A. .Mll.l.lcii I ilml,, |i B.t, I'InIc 8, KIg. S. Sjil, Aj/iiricQcriit»i (hriyi 8. A. MlLlKR | ibid., p. 31, I'lutu tt, Vi^. 0.

Siniillt;r tliiiu any other npi'cios from tlio Kookiik group. Calyx (Icprowed pyrainidai, wiilili ami lici^lit as five to tlircc, (listinclly pciitalolialu acrus.x the arm I'aci.'t.t, tin' iiiternnlial spaces wide aixl rather deeply cxenvattMl. Dorsal cup deeply ooneave to the top of the llrst disiiehids, llie second di.-^tichals and proximal arm plates spreadin;^ oulwanl with a A\^\it upward tendency. I'latos idmost Hat ; suture lines moderately well nuirked.

Basals hidileii liy (ho column. Itadials snudl. First costals ns largo ns the radials. (iuadran;rular, as long as wide or oven longer; the m'CoiuI hop- tangular, aliout as long a.s the first hut consulerahly wider. Distiehals decid- edly long for tho genu.t ; the second followed hy two series of transverse arm plates, except in the two ]iostcrior lays where in the division ajiproach- ing the anal side llu? arm plates are .supporteil hy the first palmar, Arm I'.ieets contiguous to tho second or third arm plate, tlirocted slightly upward. Anus twelve, stout at their hasos, Niendor nt their tip.s. I'innides long and heavy, composed of short joints. Interradial sjiaces a little sloping, so as to give some prominentic to tho radial portions. First interlnachial elongate, rising to tho midillo of tho socond costals, where it is followed hj- two nar- row plates of tho oanio length ns tho first, and a third plate which rests hi.'two'n the lateral extensions of tho proximal arm plates. First anal jilato a little longer tlian the radials ; it sujiports three largo plates, of which the Miiildio one is longer than the two at the siiles ; they are followed hy a largo iiumher of irregular row.s of from four to five pioce.i, which form a rounded ridge, extending from- near the hottoni of tho calyx to tho summit of the posterior oral, and wliich is .somewhat inflated in the middle around the anal opening. Tho posterior oral is highly convex, almost as large as the other

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four to^c'ilii'i' ; it is .si'|iMi'tili'i| rniiii llic lultci, mill iIh'mc rioni niu' iiiiiillicr, liy iiilliiT l.ir;^<' Miiiiili'iiiciilMiv |iii'cc.M, cvi'ii in IIh- hiiuilli'.st .'<|ii'c'iiiuMis. .^imi lai' [il.'ili's iiilci'vciii' lii'twi'i'ii llic Di'iilM mill raiiial liniiu' jiImIi'm, mi>l jiiiH.s omi' lilt* miiliiilanni. 'I'lic nnliiil ilmiii: pluicM, wiiiiji nn' ('(iiii|iai{ili\i'lj miiiiII,

(ii'i'll|iy llli' llim'^ill III' llii' li';^llirll.

Ili'ii I'll mill Lmiililij. — Kiiikllk gl(MI|i, Imlimi riiili, Mnlll^'iiilirlV <i>., Illil , «lii'lr 'aij^fi' Illlllllii'lM til' ('Srrlii-lil .s|ii riiiirlis wiTi' iililailliil.

Hi null hs. — 'llic ciiii^l iiH'liiiii 111' llii' IcMiiicii i> llic iiii»l <liaraili'i'iNlir fcaliiri' III' lliin "-iH'cirH. 'I'lii' isulalril niiils, |iiulriiiliii^- ana! riil;ji', anil lln' hiiiall railial iluiiii' |iialrH, Mpaiali' il al iiiii'i' ('111111 allinl ('uiiiim. 'I'lir |iiis|ci iiir ra\ s ui'i'asi<inall_v lia\i' liini' aniiM, lint llir iiIIiit lavs ih'mt iiiuii' lliaii hMi, mi<l III! a .s|ic('inii'n nflliis lunil Milli'r'n Ai/nriinrriiiii.'i (imhiji is liascd.

AKaricocriiuiH Whitfloldi 11 mi.

/•lull xi.ii. h'iij. .;, mill /'lull si.iii rii/s. Sii, I,.

|sr,S. Ilul ; (i.'.l !(.|i |.,»ii, \..l I , Tail II.. [. Il.'l.

bun. 11.11 : II. 1. 1 . .Sii|.|i|. iiii'iii, ri.'iii' :i, I'Ik'. ,'i

|s;:l. Mill. :,imI W..I11111..; l.inl l(r|i III n, \,,|. V , |i I'.l'.l, ri:.l.. !■.>, I'l--.. 1./, //. liii.l ri:ilr l.'l.

h"! U nii.l S|' , It.M.luM I'mIm'...'! . I':ill II . |.. 11:1.

('al\x lalliiT i.iiyi', ili'liii'.-.snl mililicliiiN|ilii'i ii a! ; llic iliiival ciiii ilccply (•iini'.i\ I', --n that, llic liisvcr cml ol' llic calyx icsl.s ii|iiiii the lii^l ijislicliiil.s.

Itasais cnlil'cly liiililcii liy ill iliiinll. Itailials Miiail, wiilcr lliall luii^r,

lic\.iii;jiilai'. I''ii--i cioI.iIh .-li;^lit!y .siiiallci' tliaii the railials, (|iiiiiiran;^iilm- (tr pi'iilaiii^iilar, raich hi\aiii!iilar ; llic .scciiml cirtal.i \ai\iii;.' Iiiiiii |icntan- ^iil.'ir til lir|ilaiiL'iilai', ami cuiisiilcialtly laiucr ihaii cilhci' i.iilials iii' fii .t. co-lal", cs|icciallv wilier. {'"iist ili-liilialM vciy lai;jc, ul iincijiial hi/c ; the

n iii| chilliest, ami liilliiweil ii\' the hivciial iinn.'^, ixcepl in the |iiistcrii)r

I'.'iS's, in wiiieli the ilixisiiins next to the mi.'ll ^<illc lia\e |ialniarM riiiiii the lil.-l (li-tii'h.ilH. Ann I'aeets Imyc ; (he aiiii Hlriicliirc iiiiKiioun. {''ir.^l iiilci- liracliiah slnirl, riiinj^ fr.'iicrallv In the nii>!ille ul' the (ii>t cii'-tals, liiit fiiiiie- liiiiei liiiicliinj^ (he .•iceiinil ; |ilates (if the .•■■.■ciiiiil riiw very Inli^' ami iiminw, ('infill;.' aliiii|illy n|i\vaiil to half the liei;jht nl" the ami faietH, where liny fire ((illiiw'cil liy Mlill iiarrnwer ones, wliicli in |imt are inleiainhiilacral. I''ii>l nniil nariiiwcr than the railialn; the (wo |ila(cs at (lie niiles of the hccohiI Mlial, which arc iniicli Inii^'cr than the (ir-'l ind'rliracliials of the other nidcH, on II li\el with the lower jiait oC the ili.slichaN ; tin) nc\t. row consisting of

f

« »

IlAIOCUINID.i;.

'tU7

live ^^lllMll(•|• iil.itc", wllicll MIC HUi'('<'ri|ri| liy iiimiiciciUh ollifrs. \'fhll:il di^k low lli'liiis|ilii'i IcmI, tint [illlli'M liril'i'i'lly Hill, rM'('|it llic lii'.''l ni'liill cliilijc iiImIi'm, wliirli nil! ^li^rlilly iimloMr, vi'iy liiij.';<', iiiiil |ilii('c(| iitjir IIh- iiiiii Iim-i"-'. Onils ill coiil.ii'l liitcriill}' ; llic iinsliTinr our cciiIimI, iwwf as liirj_'c iim (lif otIii-i'H, and iii(.i'i'|i(isri| ImMwim'ii tin-in. Iiilriiiiiiliiihii'nil jjImIi'^ \i'I'\ iinnii'i- oils, nml loriiiili^ ii roiiliiiiioiiM liii^ aiouml llii' orals, coM'iin^ <'iiiM|ili'li'ly llic ilisk aniliiilMcrii ; llioso of lln' anal miiIc an' Miiiicwlial Hiiiallii', ami its liiiliwioiiM as all ollirr inlcraiiiliiilacial plalcs to^M'llicr. 'I'lii'ic liciii^ no anal ii(lj.ri', llic |)lalcs of \\\v |i<i,sl,('ii(n' area grow Miiallcr as llicy a|i|iriiiicli llic tiniiH, wlii<'li is cxi'cnlrii! and lini'icd oli!i(|iicly ii|i\\aid.M

/liiri.dii mill l.iiiiilil>i . — Keokuk nioiiji; (iiccn ('o.. ills., and Kcokiik, Iowa.

7///" in the (Wortlieii) Illinois Slati' ••cilleelioii, SiiringHild.

liiiiiiliLn. — 'I'liis s|ieries dilTerH flciin 111! olIiciM of the hiiine liiMT/.oil ill \\w pccnliar striicliiie of the ilisk. It is only limiid in the f-haly layers, which con^titiiti- the inidillt! |iarl of llic Keokuk groii[i, and good ^{leeiinciiH (lit! (i.Ntrcnudy rare.

AKai'icooriniiH iiocIiiIohuh \V(iiiriii..N.

Villi,: \l.. riij 'J, ,n„l I'l.ilr XLIII. /■'ii/s. '/<', '>. jS'.ll, (i,..l. |(,|,. lilii,,,;-,, \„| \ III., |i. !M. I'M'- Ii, I.;.- 1,1.'.

('aly.\ liroadly |iyraiiiidal with Hiighlly concave Hides. lis hiwei lace (lce|ily cscavalcil lo tin: middle oj' the Hl'^t di.'-l ichals, rorining a r<iiiiidcd, inverted ciip, of which the posterior hide is deeply mileheil, while the margin

toward tl tlier sides incliiicH lint, very lillli'. The calyx, when placed npini

ils clorsal .side, resis upon the diHtichals, and while the inlerlirachial plali's of the i'olir regular sides almost, touch the liollom, those of the nmd ^ideale more reiiiolc, leaving, when viewed from the sidi'. a lai;.'c, li iaiigiilar xaiaiil. H|iace. 'I'hc plates occup\iug the hnsa! concavil\, cninplisiiig the ha.-ais, radials and coslals, are pcrlcctly Hat,; the dislichals and palmai.s, liouc\er, which 11)1111 ils siirroiiinling margin, arc more or Ics- convex, and iIjc liases of tiic arms almosl toindi IIk' holtoin of the calyx.

Hasals rarely visililc heyond the colnmii. lindials .-.(imcw hal ii ngiilar in si/.c, Ihe posterior ones generally longer than the others l''li-l in-lnls <|iiailratignlar, once and a half as wide as long, llnir lateral faci's iinivex ; the second as large IIS the raclials and pentangular, hislicdials ijiiite varialilc in form and si/e, us well as in iinmher among the ra\s. In the anlerloi ia\',

Hif"

X

(

,.i

498

THK CIUNOIDEA CAMKKATA OF NORTH AMERICA.

V

which generally has but two arms, tliore are 3X2 ilisliehals ; while in the riiys with three or four arms, the second ilislichal is axillary in one or liolh divisions, and is followed by two rows of pahnars. Anus ij, exceptionally three in the anterior ray, which are free above the second palmar, or third distiehal respectively, and they are heavy, long, and tapering. Pinnule.'* stout, composed of j'oints which arc nearly three times as long as wide. First interbrachial narrow and long, rising to the middle of the first distichals; the two plates of the second range as long as the first, but only half as wide. B'irst anal lon^^er than the radials, and longer than wide; the second anal elongate, wiliest at the upper end, the inteibrachials at the sides widest in the middle, all curving from within the lower concavity abruptly upward. Anus in the miildle of an oval shaped protuljerance, opening obliquely outward. Orals in contact laterally ; all convex, the posterior one n little the largest. The ambulacra arc represented not only by the usual number of radial dome plates, but by additional plates, either jjlaced in one or two series, llixys with three orms have a single large secondary radial dome plate at one si<lc, but those with four arms have one at each side. The intorambulacral spaces are somewhat depressed, and arc occupied by a few small, irregular plates.

Ilnrhjin and Li)ailifif. — Keokuk group ; Keokuk, Iowa, Jersey Co., Ills., Montgomery Co., Ind., White's creek, Tenn., and Canton, Ind.

Ti/jH\s in the Illinois State collection, Springfield.

licDiarkx. — Difl'ering from all preceding species in the greater nun.' 'i of arms, and in the form and proportions of the calyx.

^

Agaricocrinus nodulosus, v.ir. Macadamsi (Wokthen), Pia/c XXXIX. Fi<j. 6.

IS'Jl. Ji/KrifOfriniis ifurniliimxi Woutiikn; Oenl. Rep. tlliiinis, Vol. VITI., p. 01, I'l:ilr 111, Vizs. 2, 2n.

The specimen for which Worthen ptoposed the above name, agrees in the most essential points so closely with .1. nndulosns, that we think it is oidy iv variety. Yet there are some dilTerences ; the specimens as a rule are larger, and differ considerably in the form of the calyx, which is high-hemi- spherical, as opposed to depressed s\ib])yramidal in the other. The sides of the ventral disk are inflated below, the top being almost ilat, and the orals are larger and but very slightly convex. In the structure of the dorsal cup the two forms arc almost identical, and they have the same number of arms.

i I

T

mpr

nATCCRIXin.E.

•100

TTorizon and Loeallfi/. — Keokuk group; Ilnniilton, Ills., Keokuk, Iowa, and Montgomery Co., Ind.

Type in the Illinois State collection, Springfield.

Agaricocrinus crassus Wi TTrriiiiv. Plate XXXIX. Fiijs. 2a, b, and PhiU XL Firj. 4.

I8SI. Wktiikiiiiv; Jourii. Cinciii. Soc. Nat. Hist., Vul. IV., \^. I7>, I'liiti; j, \:"\\;>. 1, In, /;. 1885. W. ami Sp. ; Kcvisimi I'lila-cicr., I'liit 111., y. 105.

A large and robust form ; calyx more (''"^tinctly lobatc tlinn in any otlicr Hpocie.s of this gcnu.s. Dorsal cup almost twice as wide as high, its Ijaso hut ver}' little concave, the second row of interhrachials abruptly bent upward, and the brachials above the first costaLs inflected, which combined givt's to the cidyx a deci<ledly stelliforin aspect. Plates n)as.sive and a little conve.v; suture lines modcrntely distinct.

Basals covered by the column. Radials quite irregular, the two posterior ones fully one half longer than the others, all hexagonal in outline, their extreme lower ends bending inward to form the sid js of the basal concavity. First costals as large a.s the radials, generally cpiadrangular, the !'>wer face narrower than the upper, and about equal to the length. Second costals the largest plates of tlie dor.--al cup, twice as wide as long, and as a rule hepta- gonal, rarely pentagonal or hexagonal. The number of distichals varies considerabl}' ; all ray divisions with palmars have but one distiehal, which, being axillar}-, is followed by 2X2 palmars; those without palmars have two successive ilistichals, which are from three to four times as lonjr as the lower arm plate.s. Arm facet.s of the same ray contiguous to the third arm plate, and directed horizontally. Arms three to four in the two posterior rays, in the other r.ays their number is limited to two. Interradial spaces comparatively wide, especially at the anal side ; the first interl)rachial gen- erally rises to the middle of the second costals. and is elongate, bending slightly upward. Of the .second range of interbrachials onl}' the lower ciul is visible in a dor.sal aspect; the}' are rather broad, extend to a level with the arm ojienings, and are followed by a number of from eight to ten intcrambu- lacral pieces, one or two of them covering over the ambulacra. First anal I late longe.' than the posterior radials; the three plates above almost as wide as (he corresponding single piece of the other sides; the next row consis*.^ of four or five smaller plates, and the.se are followed by numerous irregular pieces forming a slightly elevated area, which at midway between

qip

^

500

TIIK CRIXOIUKA CAMKRATA OK NOUTII AMERICA.

the ana regions and the sunnnit of the posterior oral is pierced by the annl opening. Orals in contact laterally, large and highly convex ; the posterior one twice as large as tiie smaller orals, or larger and equally tumid.

IIoriiiiH and LuvuHli/. — Keokuk group ; Keokuk, Iowa ; Barren and Metcalf Co.s., Ky. ; White's creek near Nashville, Tenn., and Indian creek, Montgomery Co., Ind.

2'i/pvs in Professor Wetherhy's collection.

Itiiiutrlis. — This species is readily recognized by its .stellate form, the very slight concavity of the dorsal cup, and by tjje form and arrangement of the plates.

Agaricocrinus elegans aVktukkiiv. Phil,' XL. Fi'i/s. 3a. h.

1881. ■\Vi;tiikuiiv; Joiirii. Cim-iii, Soc. Nat. lli>l., Y.il. IV„ |i. 179, Tliilc 5, l'ii;s. 4, \ii, b. ISSj. W. iiiiil Sl>. ; lU-visioii r;ihiMior., I'mi 111., p. Klfl.

Nearest to -^1. cros.iiis, but smaller and less robust. Calyx deprcs.sod, pentalobate in a dorsal aspect, with rather deep recesses between the rays ; the base moderately excavated. Plates of the dorsal cuj) slightly tumid, basals and railials excepti'd ; the principal plates of the ventral disk highly convex.

IJmsmIs iiidden by the column, liadials smaller than the costals. First cost;ils i[uadrangidar, hexangular or heptangular, as wide as long ; the sec- ond costals wider than the first, and about as long. First distichals axillary in one or both divisions of the posterior raj's, supporting 2X2 moderately large palmars; tiie oilier rays have two successive distichals, wliich inteilock witli lliose of o[iposite series, and with the arm plates aliove. Arm facets tending slightly upward, conlliient to the second arm plates. Arms lliiee to lour in tiie posterior rays, and two in the other rays. First interl)iiicliials foiiiparatively short, generally rising to the first costals, sometimes to the second. Tiie plates of the second row long, reaching to near a level with tlu,' arm openings; they support a row of three or four smaller plates, which are partly iiiterbrachial. partly interambulacral. Anal area extremely wide ; tlie first plate narrower than the radials, and but very little longer, the three succeeding ones almost as largo; the latter support tliree smidler plates, and these numerous other plates, which form together a longitudinal, slightly elevated ridge, which at halfway to the orals is pierced by the anus. Ycii- tral di.sk pyramidal. Orals large and highly convex, the posterior one in

I :

BATOCRIMD^E.

501

contact with the others. The radial dome plates as large ns the orals, and represented in the posterior rays hy plates of a llrst and second order, in the other rays by a primary plate only. Interambulacral spacer depressed, the plates almost Hat. Column proportionally laige.

ILirir.on and LdcaHtij. — Keokuk groiif) ; Keokuk, Iowa, and Xiota, Ills.

T/ipc in the collection of Professor Welherby.

lumiirks. — Wetiiorby's description ia so general and indefinite, that a satisfactory identification of the species is impossible without a comparison with the type, which is not available at present.

Agaricocrinus conicus W. and Sr. (nov. spec). rhtte XXXIX Fiijs. 7, S.

Of medium si/.o. Calyx conical, rather high, width and height as 6 to ,') ; in its dorsal aspect irregularly pentalobate, the recess between the posterior ra^'s twice as wide as between the others, and the rays themselves stronger ond projecting out farther. Dorsal cup moderately excavated to the middle of the first costals; plates slightly convex ; suture lines distinct.

Basals concealed by the column. Radials varying in size, the two poste- rior ones larger than the others. First costals considerably wider at the top than at the bottom, their length o(|ual to, or exceeding, the lower width; three of them hexangulur, the two posterior ones pentangular. Second costals pen- tangular, as long as the radials and twice as wide; the posterior ones liexan- gular. The distiehals in the posterior rays consist of a single plate, which is as large as the second costals, and axillary; supporting 2X2 palmars, which are twice as long as the arm plates. I'ays with but two arms have two suc- cessive distiehals, wiiich in form and size resemble the palmars. Arm facets directed horizontally, contiguous to the .second row of arm plates. Arms broadly spreading, and moderately heavy at their bases. Interbrachials .short, rarely reaching the top of the first costals; the two plates of the second row as long as the first, and almost as wide, the three of the third smaller. First anal plate smaller than the posterior radials. but shorter than the second costals ; the interbrachial plates enclosing the latter rather large, rising to the second costals ; they are followed by three as wide Init .somewhat shorter plates, and numerous others, which togetiior form a Hat area with a ,«liglit swelling around the anus. Posterior oral as large as the others together, and in contact with them. The food grooves hidden by superimposed interam-

\n 1 1

r

1

502

TIIK CIMXOIDKA CAMKKATA OK NORTH AMKUICA.

buliicnil pieces, with occasioiially a larger covering plale among tliem. Interainbulaeral jilates very nuiucrous and coni[)araliveIy Hat ; anal open- ing lateral.

Ilofhun and Luailili/ — Keokuk group ; Indian creek, Montgomery Co., Ind.

T;/iii:s in the collection of Wachsmuth and Springer.

Jitmitr/ifi. — Tiie .specimen on Plate XXXIX.. Fig. 7, is exceedinglj- inter- esting as having on three of its arms well defined cysts, similar to those pro- duced in recent Crinoids by Jfyiostoiwi, and it appears as if portions of the pai'asites are still preserved on the fossil. This is the first instance where such cysts have been noticed on the arnrs of Pakvozoic Crinoid.s.

n s\

Agaricocrinus inflatus Ham.. Flute XLI. Fhj^. hi, b, c, d.

ISl'il. Jifiifii'Ofriiiiif iii/lii/tis — II\I,I. ; I'lvl. Dcs. New I'.-il. Fuss., |i. 4.

ISi'il. Ai/,(i-i,'iM-ri,iiii (.l,,i/j/i„nirri,iiia) l,ijl,ilii.t — IIali.; liusl. .Ii)iLni. Xiit. Hist., Vol. Vll , p. 2S1. l^rr. Aiiiiihorucrinns iiilfiitiix — S. .\. .Mii.i.Kii; Oitiil. Aiiicr. 1'iiI.tuz. Fuss., p. 7".

l5Sl. Agurii'imiiinf iiijUiliu — W. ami t^r. ; Uivisiciii I'mIu'cjci., I'art 11., p. 11;! (I'rocccd. Acad. Nut. Sci. riiila., p. 2S0).

A robust .species, in form approaching A\nphnrui'r\miH ; the s\'nimetry extremely irregular. Caly.v as high as wide and obscurely pentalobate ; the interradial spaces at the arm regions slightly impressed. The whole lower face of the caly.K Hat or concave ; the .second interbrachials. the upper edges of the first, and the arm facets the only parts of the dorsal cup visible ill a side view. Ventral disk highly elevated, broad at the top, and enor- mously inllated at the posterior side. The plates throughout the calyx are but slightly convex, barely enough to bring out distinctly the suture lines ; only the posterior oral is more or less nodo.so, and sometimes subspinous.

IJasals hidden within the column concavit}- ; axial canal sharply pen- tangular. Kadials a little wider than long, the sides rapidly spreading, the lower end thickened, forming a circular ridge around the columnar depres- sion. First co-tals fully twice as wide as long, (luadrangular, three of their sides convex, the upper straight. Second costals wider, and sometimes longer than the first, the sides spreading abruptly. Distichals 2X2; the plates short an<l cuneate, meeting laterally with their pointed ends, their wider faces directed to the outer sides of the rnvs, whereby' the facets of the con- lluent arms are brought into an even line; contrary to the case of other

w^'

•»«p

\n

n.VTOCUIXID.K.

303

species, ill which tliey meet at (in angle. Anns very long anil heavy, less tapering than usual in tiiis genus. First iiiterijiachial large, .suhovate, the upper end curved, rising to one fourth the height of the arm facets ; it is followed hy two or three smaller, elongate pieces, of which the third, when present, is weilged in from above between tlie other two, frequently without touching the first plate. First anal higher and narrower than the radials, supporting a secoml anal and two rather large iiiterbrachials. Ventral disk strongly inflated at the anal side, the anal opening directed upward, located in the midiilo of a llattened area, which extends beyond the siimniit of the posterior oral, making that side of the disk lean out of a perpendicular be- yond the line of the dorsal cup. The plates in the lower part of the (egmen are perfectly flat, some of the upper ones sliglitly elevated, but not nodose, ex'ceiil ' " posterior oral. Tliis plate which is extremely large and excentric, is pushed with the other orals to the anterior side, and stands erect, forming a part of the lateral walls of tin' calyx. The radial dome plates cannot be distinguished from the interamtMilacrals, ami piobal)!y in some cases were not expose<l at all. Interambiilacral plates quite numerous, especially on the anal side. Column rather large, the nodal joints a little wider and with rounded edges.

Jforiym ami Lui'dlUff. — Upper Burlington liiiiestone. Burlington, Iowa.

Tiijic in the White collection in the I'niversity at Ann Arbor.

Iicitmrli's. — 'I'he enormous inflation of the posterior side, making the ■whole calyx soinotiinos appear to lean to one side, the exc'^ntricity of the orals, and the flatness of all the plates, distinguish this species (juite readily from all othci-s of the genus.

Agaricoorin.us planoconvexus Hai.l. r/atr .\ XX riff. F!</s. (;„. h, c.

llfll. Ji/iiriVofriiiii^ ii/iiiinrn,irr.rii< — II .i.i.; Pri'lim. Ili'scr. P.ilii'n/,. rriii.. p. 3.

18fil. .1i/iiriri>rri,ii'.i (.loiii/niriia:) /i/:/ttn.'iiiir<:ni.r — Ham. : I!"'*!. .I"iiin. N:il. IIM., Vul. VII., p. 2S0.

1S70. Aiiiiihunieriiiiis iiliiiiii"uiifi:rii.i — S. A. Mil.i.Kli; Ciiliil. AiniT. l'j!ii'"Z. l''ii-s., |i. 7').

18S1. Jf/iinVorri/mi /ir'iiim:'iiiiiv.nit — W. niiil Si-.; Itpvisinii I'lilicu'r.. I'.irt II, p. 11 J.

Svii. J;/(iririi''riini< rlffoniif HnwiKV niiil II uiK, l^'.ll, K;in^.is Ciiy Sriciit., p. 11", ri.cli' li, Fii.'. 10.

Syu. .iyiiri'-orriiiiit Illni,-! S. A. Mii.i.Kii; W)i. A.lv. Siiccls l»tli Hep. (ii'iil. Surv. Imliaua, p. 21, riiile:!, Fii,".. 12, i;i, li.

This species probably has its closest afTinities with A. iiijfft/iin, but its calyx is .smaller, proportionally shorter — the height and wi<1th being as ■" to 5 — and less inflated at the posterior side. It is distinctly pentangular in a

a i

I I

V.

504

TlIK C'UINOIDKA CAMKHATA Ol' NOKTII AMKIMCA.

iloi'siil viow, ami tlie bottom part is wliolly or partly excavatoil. The calj'X, whuii placuil ill ail iiprij^Iit posi ion, ro.st.s eitlior on the costals or disticliuls, and leaves very little ol' the doi.sal cup but the ariii I'acets and secuiid iiinj^e of iiiterbrachial.s exposed in a sido view. Plates of the dor.sil cup (hit, and .suture lines obscure ; those of the tcyiueii flat also, iiiit their sutures are somewhat depressed.

IJasals hidden from view, forming the bottom of the column concavity. Radials longer than wide, rajiidly si)reailing. P'irst costals ralher large, f|uadrangulai', their upper faces wider than the lower; the second shorter, twice as wide as long and pentangular. Distitiials two in the cidyx, very short, especially the upper, which has a subcircular facet, ami at the V .d siile is deeply notched by the aiiibulacral groove. Arm facets large, and those of the .same ray directed at right angles. Intcrradial spaces somewhat contracted at the arm regions ; the ilrst ])late fully twice as long as wide, and attenuate at the upper end ; the two of the .second range quite narrow, resting against the first disticlials, and rising to a level with the arm openings. First anal plate one third narrower than the radials and slightly loiig(;r; the second anal narrow and long, narrower at the lower end than at the upper; the jilate at each side widest across the iniddlo. \'entrnl disk low hemispherical ; the posterior side slightly inflated, but forming no ridge or lateral groove. Anus in close proximity to the pos- terior oral, the opening turned obliquely upward. Posterior oral the 011I3' ]ilate of the tegmen which is convex ; the other orals and the radial dome plates being not only flat but comparatively small ; the former somewhat pointed at the outer end.

JT(irlr.(iii mill Livullhi. — Lower Riiilington limestone ; rJuiTington, Iowa.

Ti/pc in the University Museum at Ami Arbor.

IicniKrlis. — The depressed form of the ventral disk, the flatness of its plates, the absence of any anal ridge, and the shortness of the costals and disticlials, are the most characteristic features of this species.

A. (hrnniis Rowley and Ilarc, and A. Ilhiiri S. A. Miller, of which we examined the types — the former in the collection of Mr. Rowley, the other in that of Mr. F. A. Sampson — are identical with this species. 'I'lie latter was described from the Chouteau group, but the color of the fo.ssil and tlic matrix seem to indicate that it came from the Lower Burlington limestone. The siibquadrangular outline of the calyx, to which Miller alludes as a spe- cific distinction, is caused by the abnormal anterior ray of the .specimen, in

1 .

If J

.'»■.

IIATOCIUNID^K.

606

wliieh Olio of tlio arms is iiiulevdopcJ, ft iieculiiuity wliicli wo htive obscrvt'd occitHioiinlly ulso in otlior specius of tiiis guiuia.

AgaricoorinuB Sampson! s a. Mh.lkk. Plate XL VI. Fig. fj.

1899. S. A. M11.1.KU; Adv. Slii'cis ISIIi llcp. (iei.l. Siirv. Imli.inii, |i. 20, Plnle 3, FIk. S.

A tnodonitely Hiiiall sjiucio.x, remmkiible I'or it.s inii.M.MJve nrms, wliit'li tiro pi'oportioiiiilly lioiivier tliiin in any olliur .xpeeiL'.s l<iio\vn to ns. Ciily.x iippar- cnlly uliort ; tlic dorsal cup Hiij;litly convex; tiie bacal port idn.s lint or very little concave ; tlie interradial spaces rapidly curving upward.", • o ;!•< to give to the cup a pentangular outline.

IJasals small, but extending beyond the sides of tlio column. Tlie radials the largest plates of tlic caly.v, wider than long; their sloping lower faees more than twice as long as the corresponding upper ones. First costals sub. quadrangular, short, but longer than ligured by Miller. Second costals a little longer tlian the (irst, irregidar in outline, the upper angle obtuse. Disticlials one, as large a.s, or larger than the axillary costals, more than twice as wiile as long, wedgeforni, the larger outer ends bending inward. Anns two to the ray, ma.xsivo, gradually tapering, biserial from their origin ; those of the same ray snturally united as high as the second row of plates; the arm joints rather long and .slightly convex. Kegular inteibrachials one, moderately large. ])entangular, a little longer than wide. Anal plate one third narrower than the radials, but somewhat longer; the three plates of the second row narrow ; the two outer ones cuneate. their wider ends resting against the sloping ni)per faces of ailjoining radials; the sides of the middle plate almost parallel. Ventral disk not visible in the specimen.

Ilormm and LocaVity. — Chouteau limestone, near Chouteau Springs, Mo.

Tiii<c in the collection of Mr. F. A. Sampson.

Juiiiiids. — The type specimen, which Mr. Sampson was kind enough to send ns lor examination, lies upon a .slab with its arms si>rcading horizon- tally, so that its whole ventral side is covered by matrix. M'e regard Ai/'ir!rorrliiit>i f/frmninni and A. cJioii/crDininls, both described by Miller, of which only the calyx is preserved, as identical with this .species; the former being a young specimen, the latter a more adult ono.

64

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f

cue

TllK CIUNOIUEA CAMKUATA OK NUKTll AMKUICA.

7 I I

H

I

Agariooorinuf. bellatrema Mall. Flute XLI. Fi(js. ^a, b, c, d.

ISflU .1;iiiricuiriiiH!i oriiBlmnn* — IIai.i, ; rnlirii. Drscr. Nuw I'lilii'iiz. Koss., |i. ;1.

ISIll. .tjili-k-uci-iillli (J,,i/:iuiiiciii4ll') i,/lil/rfi,iil — JIaI.I. ; lliml. JdUUl. Niil. Ili>t., Vol. VII,, p. 2<tl.

Isr7. AiHiihuriii-riiiiii hrlUilreum — S. A. MiLLHii Ciiliil. Aimr. I'lihi'ii/,. \'m-.., y. 7n.

1881. Ajiiriciicriniit orimli-.imi — W, luul Si'. J licvisiuii I'lilinji'iv. I'lirl II., |i. \\i (I'luci'cd. Ariid. Niil.

Sci. riiila,, \<. i"«r,), imd Wliiiliilil, lb'J3, Mi'iu, An.. Mus. Nal. llisl. N. V.mIv, Vol. 1,, |i. iJ,

I'liilo i, Fi|{H. 10, ii.

Calyx .siihpyriiinidtil in its anterior n.spoct; the posterior side indtttcd nnd strongly protriuliiig ; tlio Ijiiho coniplotely Hat or very ^liglitly convex, and di.itinetly pentangular in ontliiie.

BiL'^al-' liidden l)y tlie eulmnn. tlio latter resting within a fmiull concavity formed hy the lower niargiiis of the radials; axial canal peiitalohate, Kadial.s wider than long. The first costal.s sinialler than the second and quadran- gular; I lie latter about twice as wide as long, pentangular, not larger than the radial^f. Di.stichals 1 X 12 ; the plates cuncnte, short, and V;>llowed hy two ."ieries of short arm plates. Arm facets very large, and tlitwe of the same niy contiguous up to the third plate. Arm.s ten, quite heav}- at the base, but gradually tapering and ending in a sharp point. Pinindes long and stout; their joints twice as long as wide. First interbradiials the largest plates of the calyx, and the only ones of the dorsal cup which some- times are sliglitl}- convex; subovato, reaching to one half the height of the arm facets, and supporting two narrow pieces, which rise to a level with the arm openings. First anal plate longer and generally narrower than the radials; tiie second anal somewhat smaller, the two interbradiials to each side of the same form as the corresponding single plate of the other inter- radii, but from a tiiird to a half smaller. The next row consists of three plates, of which the two outer ones, in part at least, are interanibulacral. The ventral disi\ at the posterior side bidges consiilerably upward and out- ward, forming an inllation which, owing to its large size, disturlis consider- ably the general symmetry. The median portion of this inllation, the part containing the anus, consists of a subovoid, flattened area, which is directed obliijuely upward. The space is covered by small plates, and these in turn are surrounded by eight or ten moderately largo, strongly nodose or sub- clavate pieces, a structure which gives to the anal area, and in fact to the

• Till' iinnr Aijarirnrriniif nniolmtui w.is nrigiiinlly given to this species, but not being properly formed, was aflcrwiirJs cbtingcd b^ Il;ill lo A. bcllulrcma.

X

I !

HAT()C1UN1I)<K.

.j07

wliolo ciilyx, a pc( iilinr and miiqiu' diameter. Posterior oral wtroii;{ly nodoHO, imd uliiio^ n.s Iiir^fc ns tin* four others together; it oceiii)ioM ti Miml- ing position, K'liiiiiig over to llio (interior t>U\v, where it oceupies u lower level than at the posterior side. The mnaller orals ai.d nidiul dome plutc hi^Idy convex, ahoiit twice as large as the intervening perisornie plates. Intorani- bnlacral pieces seven to nino to each Mide, slightly convex. The colmnn, which has heen ohsurved to the Iciigtii of nearly eigliteen inclies, relains the «anie width to the end. Tiio nodal joints ihronghont are consideralily wider nnd longer than the intervening ones, and at ahont 10 cm. IVom tlie caly.x tlie internodes have increased to six joints, whicli is pridiahly the largest nnndjer in this species. Farther down on the stem, larger and smaller joints alternate with one another.

Ifiifhiiii ami Liwidity. — Upper Burlington limestone, Burlington and Pleasant Grove, Iowa.

i'ljpc in the White collection at Ann Arbor, Mich.

Ji'ciiKirh. — This species is readily distinguished hy the peculiar construc- tion of the anal area, the asynnnetry of the calyx, and the llatne.s.-* of the dorsal cup.

AgaricocrinuB bellatrema, v.ir. major w. ami .'^r. (mov. var.). Plate XLI. Fig. ,1.

This form differs from the typical A. hdhttrmn in the size nnd form of the calyx, which is larger and depressed-.sphivroidal in place of .suhpyramidal, the ilorsal cup being slightly more convex, and the ventral disk shorter. As n rule, the plates of both hemispheres are more tumid, but especially those of the ventral disk, which throughout are sharply nodose, the interambu- lacral pieces as well as the others; and all plates, excepting the posterior oral, are of about uniform si/o. The jdates of the dor.«al cup are but very slightly convex. The construction of the anal area is the same ns in the typical lorm.

Ilorhan and LocaJlh/. — Same ns last.

Described from three specimens in the collection of Wnchsmuth nnd Springer.

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ir-

:m

llIK CUIXOIDEA CAMEKATA OF NOUTII AMLItlCA.

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Agariooorlnua atollatUR iIai.l. riak XXXV 111. FhjH. 7a-c.

1«3!«. Iltl.!.! (Iiol. Il<|>. Inwii, Vol, I., I'lirl II,, p. IJIU. lilSI. \V. mill Ni'. ; U. ihl.m I'liliivivr , riirl II , |>. Il:l.

Bjril. Ji/iiricocfinin ffeamelriCHi IIaLL | l>iOO, 8ui)i>l, Oi'iil. Hep. Town, p. 5rt.

A Miniill Kpocion, rcsoiiiMlng A, hclhtlretnn in (lie form of llic doiNnl nip, nml A. hiiUdtuH in the coii^'triu'lion of llio toj;MH'ii. Ciilyx Hiibjijrniiiidal, widor tliiiii iiigli. and (U.-^linitly pcnlan^ndiir aciusM the urni facetH, tlio ,xi(K>N a lit til! const lioti'd. Lower face of tlie dorsal cup Hoiiiewliat convex, tlic hnsnls and radial.i a little concave, or tlio radials Htretclicd out horizontally nnd only the l)a.sal!4 depressed. Plates Hat, with whallow grooves along the suture lines.

Biisals sonietiinc.f extending? heyond the column. Radiali* about ns wide as long, the upper face twice as wide as the lower. First costals a little smaller than the radials, quadran,L,'ular. widi'r than long, nml the upper face wider thnii the lower. Second costals pentanj,'ular, exceptionally luxangular or hep- tangular, generally a little wider than the (list, Disticlmis 2X "J in the calyx; the upper one followed hy two series of free lirachials. Arm facotH largo, directed horizontally or nearly ho; tho.so of the snnio rny forming nn nnglo of CO". Arms ten. stout, gradually tapering, and composed of rather long joints. Iiiterliriicliiids one and two; the first rising generally to the top of the first ilistichals ; the two of the second row, which are narrow nnd long, come to a lev(d with the arm openings. First anal much longer than the rndials, followed hy two rows of three plates. The n]iper part of the aiial area is composeil of irregular pieces forming a well defined riilge. wlii(di near its npper end contains the anus. Posterior oral largo nnd siiinous, the four others and the radial dome plnte.s highly convex ; interamhidneral pieces almost llat,

Il<irr:im mid Lncdlit;/. — TiOwer la3-ers of the T'liper Turlington limestone; BuiTiiigton, Towa, and at several places in Illinois and Missouri.

Ti/pe in the (Worthen) Illinoi.- State collection, Springfield,

Agaricoorinus convexus (Hai.i.) w. .iml Si-, riale XXX nil. Fiffs. In, h.

ISRO. Afiafirni-riniit imilopnmit, viir. e'inrf.riii — H\i.i,; Siipil. (iciil. Hep. lnwn, p. 58. ISOl. .li/iirli'ticriiiHa coiivexiis^W, luiJ Si",; Ucvissiuii I'lilitucr,, i'urtll., p, \\i-

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IIAKH IUMI).l■,.

fi(l•J

I 1

A very ililTi'i't'iit -pocif!* from ^1. jiiiifnijiiiiiin, to wliicli it \uin hcuii ii'lViri'd l)y lliill, ill suinu rt"<|icct.'H ii|>|irom'liiii^ Aiii/i/i<int<n'n"x. Ciily.v iie'iiliilolmti', iiiili'iiti'il l)ct\voi'H tliii iiiyH. Dorsal cu[) (U'IhuhklmI Miuct'i-Hlunpiii ; tin' viii- tnil (lixk ino^iilui'ly lioiiiiHiiliuiic, biil^iii^ at tliu pOHtvriur tt'uli'. The |iliilt.'K of lliu I'lii'iiifi' Hut, the i'iiiIIuIm mill liiHt iiitoilinii'liiulH rioiiictiiiic^ ii liillc ciiii' ciivu ; tlio<<u ut' tlio tf^iiicn tiiocu ur U'.t.s tuiiiul ; Mutiiro IIiicn (li>tiiiri Ijut not nctiiiilly grooved.

Ilu.MaI>( liidden \>y tlio coliimn. RiidiiilM lary:fi for llie jrciiu."', mm Ioii;; ii" wiilo; tlicir lower miii>j;iiH iKlleeted to form the cohimii concavity. Fii'ft costiils t|imdriinj^nlar, once and ii iialf ns wide i\s Imij,' ; wider nliove tlinn liejow ; three of its I'acuM convex, tiie upper »<tiiiiglit. Secoinl ci)>in|s not lonjrer than tho fii'Mt Imt widur, tlu; npper nnglu (jiiitu uhtnso. DiHticlials two, sliort and wide; llio upper oik; cinieate iind followed liy two iiiwf of aiteriiati'iy arraiii^eil urm pluleM, Aiin-i two to the ray, not (piite iim lieiivy ai ill Mome 'f tile prec'din^' species; griuliially tapering'. Fiist interhiiicliinls vcrj liirgi', risiii;^ to tho first disticlials; width and lenf,'lli us three to fonr. Tiiey aro followed Ity two elongate plates, and these l>y a inoilorately large niim'ier of inleraie'iulacrul pieces. Anal side very wide. The first iiniil i'>'ig.'r thill. I'radiils, Imt not as wide ; supporting three plates, which n re remarkahli : r thi'ir width, lieing almost as wide us long. The next row consists 'if jour to live small pieces, wdiich sup|)oil in the di.-U nuiiieroiis i.'l'i rs of irregular ' \. The pentauieroiis symmetry of the vi'iitral disk is con 'deraltly disturliid hy tho largo an;>l area, which bulges conspicuously from iiltove the arm regioiiH tc *]<,■:■ posterior oral; it is, however, unlike that of ,1. hilliih-dii'i, being compos Mt of almost Hat pieces, mid bordered by a shallow groove at each side. Anal opening directed obliiiiiely upwards. Posterior oral excentric, being pushed over to the anti'iior side ; it is as I irgo as three of the t>thers together, and strongly nodt)se, while the oihcis are but little convex. The radial dome plates, if represented at all, were small, not much larger than the intorambuhicrals, which in this .species me (piito numerous.

Ilariyin imd Lurnlifi/. — Upper Burlington limestone; Tliirlingl()u, Iowa.

liimdi'hs. — Hall described tlii.s species as a variety of Aijaricin'r'nnis jmi- ^/^'<»il^? as follows: "Base convex; arms small; all the plates of the dome tubercidous." Not only is this description insufficient, but it is partly incor- rect; tho plates of the ti'gmen being convex but not tuberculous. The pres- ent description was nindc from a specimen in the collection of Wachsmuth and Springer,

510

TIIK ClUXOIDKA (AMKISATA OF NOKlll AMKKKA.

\'ii\n.

Agaricocrinus Coreyi (l.vnv ami iass.). J'hik A'A'AVA". /•■/;/,>■. /.^ />.

.Ir/iiiiirn'iiiit Ciiryi— Lmin »m\ ('a.'.>kiiav ; Aiiiri'. .Iiiiini. Si'i. (mc. mt ), Veil. XXIX., p. 7<>- .\mi. .I^i,i,ii;„;-i,iiii Spnih/rri — WiiiTE, 1.">M j lilivciilli Aim. l(i'|i. licul. imA .\:i1. llisl. of liiillaun,

Of iiiDi'o tliiiii iiu'iliiim .-iizc. Calvx a little .■<lu)i'ler tliiiii wide. I)oi.<;il Clip riitlior lujj;li for tlic gciiii,-*, but soinewlmt lowi'i- tlmii llif vi'iitial (lisl<. suioor-sliiipod. tniiR'alL'd at tlie bottom, tlio sidos oonvt'X. I'lati'.s fli'vated. ^'ometimL•s a liltio angular, tlioir surl'aoo .smooth; future lini'S di.stini'lly groovi'il.

IJasals latlu'r small; on a K'vol with the radials, and forming a hexagon, which is almost completely hidilen by the column. IJadials stietched out hori/ontaiiy, except the uppermost part which bends slightly upward ; they are twice as large as botii costals together, and one third wider than long; their up[ier faces excavated and broader than the widlii of the plate at tlie botiom. Costals twice as wide as long, the first (jundrangular. the .scimuiI jii'nlangidar and rrc(|mnlly smaller than the fn-st. Distichals two in ilie calyx, very short ; tlio first wedge-shaped ; the second linear, followid by leaf-like cuneate pieces, which interlock from opposite sides. Arm facets huiate. nnusually large anil directed horizontally. Arms unknown, but ap- p.ireiilly very stout. First interbrachial large, generally longer than wide, followed at the arm regions by two (dongate i)ieces in the second row. and these by seven to eight interanil)ulacral ))lates. First anal jilate con- sideral)ly longer than th(> radials. and forming with the two succeeding ones a vertical row; second anal about one half the si/e of the first, the third very ninch smaller. IJoth these plates rest between two interbrachial pieces, of wliicli those in the first row are very large, but those of the second iiuile sm.ill. \'entral disk |)yramidal. pentangular in outline, the plates con\ex. I'o-ierioi' oral conii'al, centr.il in positiim. and thre(> times as large as the fiinr others. Interambulaeral plates rather numerous, about one fourth the si/e of the smaller orals. The rays are surmounted by a large lailial |ilate. jilace(l close to the lower margin of the disk. Anus excentric. directed ob- liipu'ly upward, and occupying the upper end of an elongate, flistinctly roinided area, composed of small, smooth, irregular pieces.

llirl"iin II, III l.uriilili/. — Keol<uk group; Ilardin and Allen Cos., Ky., and Vermilion Co.. Ind.

7''//(c in the Fiyon eoUeotion.

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UATOIUINID.K. oil

AgaricocrinuB brevis (Haii). ri,ilc XXX Vlll. Fi</,s: ,'<(-<■.

1<;,"S. ./,///w.v//i«i liivrh— II vi.i.; (iinl. l{c|). luHa, Vul. I., I'arl II , p. Ml, I'hilr 111, ri(,'>. ;(«, h, Issl. ./y,(/iVw/-///«j /viTiJ — W. mill Si'. ; Kcvisiiiii l':ilunci-., I'lirl II., p IIJ.

Sjii. Aclinui-iiiiii.1 eV;'/((',rt/«,« — 1I.VI.1., l'<.i!>, CIcul. lii'ji. lu«;i, \ "1. I., I'liil 1 1 , |i. ."iliii, I'hiU' 111, l"i,l,'S. I.(, li, c.

A .'iiiiiiU and tleliciite .species. Calyx wider tliaii iiij;Ii ; dorsal eiip and tegiiieii of the same iieiglit. The lower pari of liie (lui>al ciiii to the lop of the radials slightly coiieave, tlieiiee s[)reiidiiig raliier ahnipily to tiie arm liases; tlie iiiti'rradial spaees slightly depressed and somewhat eoiitiiu'tcd at the arm regions. All plates below the arm regions thickened, and rising aliove tlie suture lines in nodose or tulierculous extensions, with short, ineon- s[iicuous ridges reaclung to the siiles of the plates, where liiey meet witii the ridges from adjoining plates.

IJasals small, Ibrniing tiie bottom of the column depression. iiadials a littlo longi-r than wide, their riilges occupying only the upper end of the plates, the con\e\ lower part iieing perfectly smooth. First costals small, (piadrangular, the sides convex ; the second pentangular, shorter than the lirst hut wider. Distichals 2 X 2, very short, sujiporting the arms. Arm facets large, suhcircidar; the and)ulacral openings larger than usual in this genus. Arms ten, hea\y, slightly increasing in thickness to half their height, then tapering gradually, and ending in a sharp point. l"\v-\ interlirachials large, nearly as wide as long, rising to the top of the first distichals; the two plates of the second row very narrow, three times as long as wide. First anal plate a little narrower than the radials; tiie three plates aimve. which are almost as large as the oorresptjuding single plate of the four rt'gular sides, are I'ollowed hy four or live small pieci's, and these hv numerous lows of still smalK'r ones, wiiich form a ridge, with a well delincd groove at the siiles. \'entral disk comiiaratively short, hemisplici ical. with a large plate in tlie centre. This plate, which represents the posieiior or.il. and is almost as large as three of the other orals, is surrounded hy eight slightly cnnve.x plates, four of them orals, two overlying the posterior andudacia. and (wo ilie anal side. The radial dome plates, wiucdi are so prominent in other sjiecies, either are uni'e])rcsented, or cannot he distinguished from the inter- amhnlacral pieces, which are of moderate si/.t>, and only sulViciently tumid to hring out distinctly the suture lines. Anus directed laterally, located iialf way hetweeu the arm openings and the suinniit of the posterior oral.

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512

TIIK tHINX)II)i;A CAMKllATA OF XOKTU AMKUR'A.

Iliirr.iiii and Lunditj. — Lower Burlington limustono ; Burlington, Iowa, nnil souiliiTii Missouri.

Ty^ic in the (Wortlion) Blinois State collection.

Agarioocrinus fiscellus (Ham). riak XXX VII I. Fi.js. J,i, h, c.

I'SOl. ^i-f!inii-ri,inf,/iirr/!iis— Ilvi.r.; HhsIcim Jourrj. Nat. Ilisl., Vul. VII., p. i7i. lS5l. Jyi/Wi'u, •/■/««.« .//<(v7/(H \V. anil Sr. i Kcvisiua I'alu r., I'arl II., p. I U'.

Of the same size as .1. /;/v//s, and .so closely rcseinhling it that it is quos- tionaljle whether it is not a nieie variety of that species. It dilTers somewhat in the proportions of the calyx, the dorsal cup Iteing comparatively higher, and tlie fegmeii shorter. It is also more distinctly pentalobatc, the inter- radial depressions at the arm bases being deeper. In the ornmnentation of the plates the two species are similar, if not identical. In the form under consideration, the plates to the top of the radials are horizontal, and those above curved abruptly upwards, with little increase in the width of the calyx. Tiie basals I'orni a he.xngiui with a shallow depression in the centre for the reception of the coliunn, leaving the outer margins of the basal di.sk exposed. Badials wider than long, the upper part a little nodose, but without ornamen- lation. There are two disticlials in both divisions of the three anterior ra\s, and also in one of the divisions of the two po.sterior ones ; while the divisions next to the anal side have but one, which is axillary and su|)port.s at each side a short palmar, making three arms to the.se rays against two in the others. The arm facets are smaller than m A. hnrls ; the arms not quite .so heavy, but apparently a little longer. Tegmen very short, depressed hemispherical ; the posterior oral largo and sharply conical ; the other ])lates slighth- convex. The anal area is formed as in the preceding species, but i.s souiewhat more bulging.

Iliiri.iiii null Lofdli/i/. — Same as last.

T'/jir in the University Museum at Ann Arbor, Mich.

Agaricocrinus pyramidatus (II mi.). Phite XXXVin. Fl'js. 4a, h, r, awl oa, h, c.

T>.'iS. .l-Hnni-riiiin i);/r(n,ii.liihi>— II mi.: Hi'd lirp. I..w:i, Vul. T., T'lirt II . p. :)fi.">.

l''''!. .l./iiri.-'',-ri>iii.^/ij/riiiiii'/ii/iif—\\. ami Sv.; Ki'visiun I'.'ilii'dd-., p. 11-J; and I'll):!, Wliil field, Mi'in.

.\ini-r. Mils. XM. IIUl,, Vol. I., p. i:\. I'l.Mc i, Fii;v i:\ and ■.'.■>. Svii. .(/.'ivV'./w/w rnrrn'iii/nt ll.\i,L; ISOI ; rrclini. Descr. New I'ldiKiz. Fu^s., p. 4, and llnslon

Juurii. Nat. llist., p. i^i.

U Ua

BATOC'HINin.K.

513

M Ko

Another sinall spceicH of llie tjpe of .1. Iirtn'.i, but its cal^'x sliortur and of somewhat diilVreiit form, being about twice a.s wide n.s high, and iiyi'ami(h\l in outline. Dorsal cup sharply pentangular and distinctly llatteiied at the bottom. When placed on end, it rests npon the eostals, the basals and radial.s ionning a .shallow, funnel-shaped concavity, and the distichids bunding .slightly >ipward. The custals and distichals curve to tiie sides, so as to form a depression at the intcrradial spaces, and each plate has a narrow, transverse, angular ridge. The suture lines are distinctly grooved.

Radials rapidly spreading; their upper faces twice ;i- wide as their lower, the upper end thickened, corresponding to the tr nsverse riilges of tiic i)raciiial.s. First eostals very short, more than twii e as wide as long; the jiccond a little wider and longer in proportion. Distichals alino-t MS short as the free arm plates; the second considerably wider than the first, and Ibllowcd by two scries of arm plates, of which the two inner series of the ray interlock with the second free plate, /. c. fourth plate from the axillary. .Vi'in facets largo, conlluent, and those of adjoining rays idniost in contact. Arin.s ten, massive at the bases, (juite thin at the extremities; conii)i)sed of two rows of .short parallel joints, with transverse, obs'.-urely angular ridges. First interbrachials large, attenuate at the upper end. tiieir surfaces convex ; the two of the second range long and extremely narrow. The first anal, which is fully as long but not as wide as the radials, is followed by three elongate pl.ites, and these by a large nund)er of irregular pieces, forming a .slightly rounded, ridge-like elevation, with a groove at each side. Anus close to the posterior oral, opening out oblicpiely upward. Ventral disk depressed pyrami<lal ; the orals and radial dome plates distinctly co: vex, the interambulacrals almost (lat.

Horizon and LuruUli/. — Same as last.

Tiipis in the (Worthon) Illinois State collection, and in the University Museum at Ann Arbor, Mich.

V 1 1*1

Agaricocrinus gracilis ^r. and w. riitle XLI. Figs. 3a, h, c.

1S61. yU.r.K 1111(1 WoiiTiiKX J rrdccril. \cm\. N.it. Sd. Tliiln., p. 135. l-^si. W. .111(1 Si'.; licvisioii Pidu'ocr., Part II., p. 119.

Somewhat smaller than A. hrcri-'i ; the calyx wider than high ; in its ventral aspect decidedly pentangular with concave sides. Dorsal cup de- cs

«i E<

G14

Till-: CUINOIDKA CAMEUATA OF NORTH AMKUICA.

I'i^

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prcssi'd, the bottom concave to the inidtlle of the first costals, whioli together with the first iiiteihracliials ami second anal plate are genicnlateil, or ali- iiiptly bent npwaiil, and swollen so as to form a circle of hiMnispherical nodes aroMnd the margin ol' the concavity; the npper portions being almost vertical. \'entral disk depressed pyramidal, with a short conical spine at the siinnnit. Surface of plates througiiout the calyx finely grannlose. and sufii- ciently convex to bring out the suture lines.

Uasals hidden liom view, occupying tiie bottom of the column concav- ity, h'adials aljout as wide as long, all hexangnlar in outline. First costals slightly larger than the nulials and quadrangular; the .«econd not longer than the lirst, liut often considerably wider, and provided with an ol)tuse mesial ridge, wliich connects with the prominences upon the first. The distichals from the second up are free. The arm facets have a slightly upward tendency, and those of the same ray are placed at right angles ; arms a little longer and more .><lender than in ^1. Iinrl.i. Interradial spaces wide and somewhat depressed in the npper portions, a little con- tracted at the arm regions. First interbrachial large, curving abruptly upward ; followed by two elongate pieces, and a snudl (piadrangnlar one, the latter ()ccu[)ying the arm regions. The iuteramiiuhuM'al plates consist of five or six [)iece.s. The two lower anals vary considerably in size; the lirst being in some specimens not longer than the radials. in others almost twice as long. In the lattiT case the lirst takes part in the circle of nodes which form the lower margin of the caly.v, in the other it occupies together with the radials the lower concavity, and the second anal is nodose and forms a part of the circle ; the interbrachials at the sides of the second anal are elongate and widest in the middle. The next row consists of three smaller plates, which are succeeded by numerous irregular still smaller ones, forming an almost Hat area. Anns directed laterally and jdaced low down, a little above the arm opening-:. Posterior oral large, high conical or subspinous; the four others are .scarcely elevated. The radial dome plates somewhat projecting and moderately convex.

Iforhun (dill LiiniJit,/. — Upper Burlington limestone, Burlington, Towa.

y';/fc in the Museum of Comparative Zoology.

L'ciiiarlif!. — The circle of tuniiil plates at the lower margin of the calyx distinguishes thi.s species from all others.

I

/

BATOCIUMD.K.

615

IIAimOCRINUS Angeliii.

Siibgcmis ACACOCRINUS '<V. and Sv.

('Akokot siinple, x/jiVor a lily.)

Ciilyx short, cyatliil'orm. Basals tlireo, cqtml. Hadiuls nitlitM" Invirc. Costaln two. The di.sticlials givinir oil' the anii.><, whidi niiii\iii simiile. aiid are composcil of ciiiieato pieces alteinatelv arniugeil, interlocking or not. Intcrl)racliials in contact with tlio interanil)niacr!ils. Anal side wide, coni- po.sed of nwineronn plates arranged in longitndinal rows, of wliiih tliere arc generally three. Interdistichals not observed. Strncture of ventr;d disk and form of nniia not known. Colinnn ronnd and large.

Disliifiiitimi. — Only known from the Niagara gronp of Indiana.

Ti/pe. — Acdnicriitiis E/roili.

Ilcniarkx. — We attempted at first to place the fcdlowing two species under Carjxirrlniis, but were unable to do so. .Toll. Miilier pioposed tliis genus for " die mit den Artimicriiin^ bislier vereiniglen Crinoidcen. dencu aueh das unregelmiissige ni/irnn/iu/i aller wahren Crinoiileen felilt." His definition docs not apply to Cur/im'i'iiiiis niinji/r.r, M'iller's type, if Angclin's and Zittel's identifications arc correct, U)v it lias, according to their state- nuMits, an anal plate interposed between the radials. Tliis.it seems to us. dis- qualifies Miiller's •.;ame from fnrllier use, and it will liave to l)e reiilaced liy Jfi(liriiiriiiiis Angelin. But from this, anil froui the subgenus Drsiiti'liKrlmis, onr form diflers. at least the typical .species, in having cuneate interlocking arm ])ieces in place of transverse single joints in Ifufinn-riinin, which we tliiuk is sufVifieut to separate the two forms subgenerieally. as all other species of Ilidjivcriinm have ri'Ctangnlar arm plates.

S\' ij

/

T

Acaoorinus Elrodi* w. and Sr. (nov. spec).

Platv XXX TV. f;<i. Id.

A small species, not over 'J I mm. from the top of the stem to the to]) of the arms. The i)lates of the dorsal cup a little convex and smooth ; the median line of the costals and distichals slijrhtlv iinunlar. IJasals forminir a rather large obeonical cup, truncated at the end. IJadials very large, as long a.s wide or a little longer, larger than the two cost.ils together, the ui'per face concave. Co.stals wider than long ; the second smaller than the

• Niiinc'il ill lidiinr 111 Ilr. .Moses N. KIrod, oiio (if (lie |iiciiiccr |;eiil(igi-i> uf Iiuliaim, wlio collcclfil llin only known ${ii'ciiii('n.

I 11

1^

olG

THE CIUNOIDEA CAMERATA OF NORTH A.MEltlC'A.

Ilist. Anus iiKMk'iately long, lililorni at their upper cuds; couiposeil of cunoiite joiuts, iuttMiocking to Msevial. Pinnules comparatively strong, and composed of veiy long joints. Interbnicliials: 1, 2, - ; the first consideralily larger. Amil side very «ide ; the first anal smaller than the radials. fol- lowed by 11 series of four other anals longitudinally arranged, and having at each side, and in contact with them, rows of I, 2. and 2 plates.

lliiiixun iiHil Locii/lti/. — Niagara group; llartsville, Barlholomcw Co., Ind.

'J'l/jii' in the collection of Waehsmuth and Springer.

i

h

Acacocrinus americanus w. and Sr. (nov. siioc).

r/,i/,- XXXIV. y-v/.v. /-w, h.

Dorsal enp ohronicnl, wider than high ; the sides convex, spreading more rapidly from the top nf the hasals to the top of the radials; the intcrradial Hpaces llattened and the cross section ohscurely pentangular. I'latcs hut very little convex, their surfaces apparently smooth, the suture lines not grooved. IJasals forming a shallow, slightly spreading cup. Kadials as large as both costals together, a little longer than wide ; the iijiper face concave. First costals generally (luadranguhir, the posterior ones occasion- ally pentiingular ; the second costals pcntangidar or hexangular. the angle nt the upper face very ohtuse. Distiehals one only preserved in the specimen, quadrangular in outline, as long as the costals hut much narrower. First interhraehial almost as large as the radials, and about ns wide a.s long ; the second row consisting of two nnich smaller jilates. Anal jilate somewhat smaller than the radials, ami the three plates above not nmre than half the size of the (Irst interhraehial of the regular sides ; the succeeding row con- sisting of three pieces of the size of the distiehals. All otlier purf.s unknown.

If'irhnt will T.iii-nlilii. — Niagara group; St. Paul, Tnd.

2///'C in the collection of Waehsmuth and Springer.

COMPSOCRINUS s. A. Mii.r.F.ii.

ISS:?. S A. Aril.i.Kli ; .Tniirn. Ciiioin. Snr N;,|. 1[1m , V..1. VI . p 3;i;!.

Svii. lll,i,il,„-,-i,tH, (in pnii) — Mii.I.Kii ; ISSl ; iliiil., V..1. I v. ( Npril iiimilicr). V\\\\r- T.. T'iu' «■ Sui. Miirini-riiiHx (in \\\w\) — W. iinil Si'.; Iss.'), l{(■vi^illn I'riliiiirr., I'lirl III., |.. |ii| (I'lnri'iil. .\c:iil. \ .1. Sii I'lilhi . IS'-.".. I'. :!•,'<•,)

In it-i general habitus resembling (lli/iiliirfliin^. but having an anal ])late between the radials. and only four hasals. Lusals large, unequal, two of

' V

BATOCRINID.E.

ci;

tliem angular nbovc, the other two trunriited, one of the latt.T siippoit- iny the first anal, the otlier the anterior radial. IJadiaU generally wider than the two eostals. Distiehal.s two when ijaliiiars are reiireseiited, hut five or more if tiiese are wanting. In the latter case a stout iiinnule from the serond distichal takes the plaee of an arm, ami the jilate above is not pinnule-hearing. Arms long and slender, composed of cnneate single pieces. Pinnides stout, given oiif alternately from oppo.'site sides. Inler- braehials, interdistiehals. and interpalmars numerous; the anal .side wider, with a longitudinal row of anal plates, followed by a strong ridge. Ventral disk composed of minute irregular jjieccs. Position of anus unknown. Cul- mnn quadrangular; axial eaual small, iientangular ; the angles Interradially disposed.

Dit/rlbii/ion. — Upper part of the Hudson River group of Ohio.

Ji'iiiiiiih. — CoinjiKiii'i-iiiHti Ilan-is/'. the typo of the genus, was originally described by Miller under (i/i/pdicrlm'x, and nothing was said of the first nnal forming a part of the radial ring. Neither was Wm^ noticed in 188.'! in Miller's geiioric description of CiniijisorriiiiiK. but his diagram .show.'! it, and he also statc(l it in the revised specific description. The structure was over- looked by us in 1881 when Ave referred the .sjiecies \o Munncrniiix. Since then we have discovered that Miller's " G/iz/i/arnnnx" tnlmiil' usis also belongs to this genus, having a quadningidar stem, and four basals supporting six plates.

Compsocrinus Harris! s. a. jIilleh.

riiiic XX r. Fiijs. 8ii, h.

1^81. GI'/jiffirrinHf ll,rii»i— S. \. Mii.i.iiu ; .Imii-ii, riiuiii. Sue. N;i(. UUt. Vol. IV. (April iinnilioi),ri,i(i'

1. Fins. t. U. lsS:i, C.mim-ri.iHn lUinhi — S. A. Mii.i.Kii; iliiil , Vi.l. VI., |i. i\\\. Tlalc II. I"ii.'s. 4, \,i. lbS,i. Miu-iiicrhiH' Ihiiihi— \V. iiud Siv ; Krvisinn l':ihi'iiCT., I'ail 111 , |i. 101.

A small highly ornainented species. Caly.x higher than wide; rapidly e.\|iandiug to the middle of the first costals. less spreading above ; interradial areas depressed. Surface covered with prominent ridges, arranged into w«ll delined stars with intervening triangular depressions. liadial ridges wide nnd prominent. occu]iying one half the width of the jdates, rounded on the back, and wider at th(> ends of the jdates than at the middle. The ridges toward the interbrnchials lower and flattened at the top. but like tjio radial ridges stoutest near the suture lines, a peculiarity which is also found at the interdistiehals and interpalmars.

u ^'*1

ij v

f V Jl

II

II

51S

TIIK CRIXOIDKA CAMKUATA OK NOUTII AMKIMCA.

Dasala small, oiil^' tiicir upper angles exposed l)eyonil tlie c'oIun\ii. Radi- ala iiiul uoijtulH nearly of uiiiloriu xizu. Di^stieimis twu, a little sinaller tlian the costals. Pulinais five or six in tlie calyx, comparatively large, very gradually decreasing in size; Hticcccded by free arm plates of the hanie order. Arms twenty, not hranehing, slender, eylindrical, composed of sliort euneiform pieces. Interbraeliials: 1, 'J, 3, 2, -, '2. t/c. ; the anal .•«ido wider, containing a longitudinal row of anal iilate.s marked liy a strong ridge. Interdistiehal and interpahnar areas unusually la>'ge, the former composed of five or more rows. Construetion of ventral disk not known. Colinnn iiuadiangidar, with rounded angles and slightly concave sides.

Il'ii::ou uiid Lovallli/. — Upper part of Hudson liiver group, Waynes- ville, O.

Ti/pe in the collection of I. II. Harris, Esq., at Waynesville.

i

I

I

Compsocrinus miamiensis (!^. A. SIillkr). I'hth' XXI. Fl<is. 7ii. h.

IssJ. Gh/plnerimii mliiiiilfiitlt — S. A, MiM.Kii; ,li)iirii. Ciiicin. Sue. Ni\t. llisl., Veil. V., Pliitc 1, Fif;. 1.

lsS:l. (Hi/iilucriiiiis miKi'ii'ii'is — \\ . ami ><i'. ; .\iiiir. .luiirii. Si'i , Vi.I. XXV., |i. ili.'i.

1S53. Uli/jitiifriiiKt iiiiiimifiiu.1 — S. \. .\Iir i.kii; .Imini CiNcin. S.ic Nal Ili>l., V(p1. VI., ]i. 2'2t.

1SS5. Gl^ptveriniia itiitimlffi-^is — \V. and ^p., Urvisinn riiluMicr , Part III , y. 104.

Calyx elongate; the rays followed by strong ridges, which occupy one half the width of the plates. Tliero are no ridges upon the inlcrbraehiids or upon any of the other jdates, the siirfiice of the calyx is covered with minute, irregularly arranged pustules, which are not readily seen except under a magnilier.

IJasals moderately large, forming n good-sized cnp ; the posterior one largest and l)roadly truncated above; the truncate face of the anterior one somewhat narrower; the two others forming a right angle. Itiulials and costals of ai)oiit ecpial size, but in the former the proximal siile is angular, in the others the distal. The po-^terior rays have two large dis- tiehals, followed ',>y throe to foiu' palmars which support the arms ; the three anterior rays have from four to five distichals in the calyx and no palmars, giving fourteen arms to the species, Interbraeliials: 1, 2. 2. 2. 2, c/f. The anal side has an additional row of nnal ]dates following the median line. .Structure of ventral disk and anal ojjening unknown. Colmnn ob- .^icurely quadrangular, with a snmll pentangular canal.

T

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T

i

BATOCIUMD.K.

01 'J

Jl'irkon ami Liinillli/. — Uiipur part of Iluilson River group; Wii^iics- villc, 0.

Tin>e in the coiluctiou of I. II. Harris, Estj., Wii^ nt'svillc.

U. PERIECIIOCHIMTLS.

^tf^

T

PERIECHOORINUS Aishn.

^^^i. Ai'sTiN! Ann. \- Wns. .\;it Hist., Vol. X., |i. loi) („„ ,1, lliiiii„i,). ISl.'t. Alslis ; illiil., Vi>l, XL, |>. JIKI.

I8t:i. Mouuii; Ciiiiil. Mm, ^■n^^. (i:,l. I), p. 5(j (K,l. i, p. sc).

IS.-i.-). M(C(,;| SviM)|is. lint, V»\i\-u.. Ku-^., p. ijli.

is.-,;. I'lirtr; Tmiii' il.' riilcmit , Vdl. IV., p. UX

18.')9. MriKilIsiiN; Siluriii, p. .'illfl.

lSfi2. DrJMihiN iiMil Mri'K; Hist. Niilur i\n /,iin|ili. Krliiii., p. Kl/.

1S7S. A.VI.KI.l.S J IfdlilPUT. Ci-iu. Slice, p. tl.

lS/9. ZlTTri.; Iliuiilli ili'i- I'lili I., Veil. I,, p. ;ii;i».

ISSl. W. mill Sf. 1 UiviM.iii I'liJii'.KT., I'liil II., p. l-.i7 (I'lMcci'il Arnil. Nut. Sri, I'lilln , p. ;i01).

Syii. .i-liihiri-iaih-i — J. S. Mii.i.ik; \^i\, llistiiry iif llu: t'liiiiiiilca, p. Illi.

Syii. .l.-iiiiurriiiiif — I'liM.i.ii'.H; IMl'.l, Muirli. Mlur. .SyM , p. (i;;l, I'lulr Is, t'ijr. 4.

Syii. Ti-iii-liui-ri,iiles — I'liuTMic k; Itt^, (li'i,|. df Ldmliiiulirry, p. ,'il.').

Syii. {:)l'i;hh„;i,i„.< — \h. Vkknki II.; !s.JO, Hull. Sue. Gi'dl. KnuicT (mi-. II.), Vul. Vll., p. ISl.

Syii. tlfncriiiiif — D'tlmiidsv; Is.VI, I'luilr. ilc I'uIi'diiI., Veil. I., p .Jil.

Syii. Siirro,riiiii.< — 'I'liiKisT ; h.'iO; l.i^l iil' Criii. Trim, (lid ili^rriiiliuii).

Syii. Siif-fuiviiiii) — llAi.i.i |s.")i', I'lilii'diil. N. Vdili. Vdl. II , p. ■.ill.').

Syii. /yri7.«v//«M — .MCi.I.Kii; (in piu'l) ; IS.')", Xnir iOi'liiii. Kill. K:ilk., p. ■.'."i.'t.

8yii, {;)Ti-oflin,-i-i,iii,'.i — I'vsiiKli, ISjS, llrlniiTsduN Hcdl. liiincik. mil' ciiiiT Uii^i' in Swciliii elf. p. i!0.

Syii. Siicroi'i-iiiin — V. HoKMiii; |S(',i), Siliir. Viiuiiii Wf^l Tiiiii, pp l-.'-ll.

Syii. .U-li'i'ii-niiiix (\l,:ii'lu,;-i:iu<) li.ti.i, ; |s|ll, lidsl. .Iduni. Nui, l|i>i , p. i;!.

Syii. .l,-/i,iwri,iii< (l',;i,/,„riiiii<i — Sl. mnl W, ; Isiil, rrdcvi'd. Aciid. Niil. .Sii. I'liiln,, p. I,'i3.

Syii. .Ii-/i,ii,rri/iiif—]\\\.i,, ISli:!, Ti-aiis. Alb. Iiisl., Vul. V,, p. l!)l'i.

Syii. .l/.''//»/w/M«j— \Vi\i II. 1111,1 Maiuv; ISO,'); (iidl O. mill t<ii.), Mnii. Ildsl Sdo. Nut llivl , I., p. S7.

8yn. .l,-lhif„-ri,„n (S,„-rorrl»«<) — M. mill \V. ; Isfii), fl,„I. Il,.p. Uliiidis, Vdl. TIT., pp. 317 iiiid 170.

Syii. .1/.7//.«/u.','////M (i',(,vmr/'««.) M, mill \V,; ls7;t, (Irdl, |{,p. Illiiidi.s, Vul, V„ p. ;)'.i7.

Syii. .V,(,v,„v/,/fft— Ham, ; |s7(l, istli U,.p. \. V. st„tr Mn,. \,||. ||i,| (lirvisnl K,| ). p. U'7.

Syii. Siiirorriii/is — S. A. Jlm.KU — .(mirii. riiiciii. Sue. Nut. Hist, of IhSl miil ISsi.

Calyx h\v\n\ dongafc, boll- or urn-sliiipod. Tliitos lliiu, iiiul llifir siirfaccH smooth or (K'licatcly .iciilptiiroil ; tlic railial plates jronornlly liaviuir a ridge passing from plate to plato, wliicii iiicroa.scs in promiiieiU'o iipwarils until it becomes itlentilieil wiib tbe fiee ann.s,

Basals throe, equal, forming a deep oup ; cdlimin faoot wide. Radials and costals long and narrow ; ennstrietod at flicir upper and lower faces, sometimes eonnortod merely by the point of an angle. Costals two. hex- angular and heptangular. Distiehals in two to four rows; supporting fiom two to SIX palinnr,s, except in a few cases wiiere the arms are free above the

iK:

I

I \

I

i J

uUU

TIIK (HlN(>lI)i;.V CAMKUAIA OK NuIHH AMKUIC A.

I

(li.sticliiilK. Anus bnuR'liiiig in the biMciial ^tato ; lung, xlcntloi', ruundcil ; con.stnictcil (Voni tlicir Imson up of u duuMu worics of intciiuoking jiiuct's. I'inniilus ("londor, clo.'ifly coniiguous. Intorlniicliial and intordi.stiilial ^[jai'ed long and Harrow, coniposi'd of a hirgu niunboi' of plutuM. Fir«l interbiacliial largi'i' than the Miu'ct'L'diiig onoo ; su|ii)t)iling iiiiniiTonw iowh of two plates each — rarely three, and only in the u|ipt'r rows — whiuh pii>.s iniperoeplibly into interiinibulaeral pieees. Anal interrailins very wide ; the lirft anal .similar in form to the radials; there are three plates in the iie\l range, and lour to -ix in the Mneeeeding ones. Interdistiehals present, and variously repre- sented by from three (o six rows. \'entral disk di>pres.«ed. from moderately eonvex to almost Hat; eompos^'d entirely of wmall. irregularly arranged plates, apparently without orals or radial dome plates, except cloxo to the nrmn, where sometimes the covering and side piece." enter the margin. Anus subeentral. Column large, eyiindrieal ; axial eanal nuxleralely wide and eireidar.

Difli-iliiiliiiiL — I'diifhitciiiiiiit is found in the Niagara group ol' America, and its eijuivalent in Kngland and Sweden. It also occurs slightly nmdified in the Upper Devonian of Spain, and in the liowcr Subearbonilerous of the Mississippi Valli'y.

7,Vy;(' of the genus : Pii-lirhicrtinis m<>iilHfi>rniis (J. S. Miller).

JiiVKirfiH. — Austin's definition of Ptrlic/iocriiiiis is not as clear as could be wished, but it is enough to indicate tliat he ril'cis to a group of Criuoiils of which J. S. Miller's well known ArUiKH'riiini viiDilH/'ifiiii.t is the type. The species are remarkalile for their elongate, sac-like foi'in. the thiime.ss of the plates, the great length and .slender form of the railials, the width of the nnid interradius, and the branching of the biserial arms, substantially the same churacters upon which afterwards Hall uiulerlook to .separate the i^cnus Sncencriinis.

In the Revision, Part II., we placecl under I\riii/i(irrliii(s not oidy the -jn'cies which had been refi'rred to Sui-rncriiiii.i, but several others from the Lower Carboniferous which had l)een described variously under Acliiiocriiiiin, J]f>fjisfiirriiii(s, Sitirncrimi-i, and I'mil'irriiins. These species, which embrace Arliii'irriiiiis (}fif/i!iliiirlnux) Wliitti Ifall. Artinurrhnts { I'raih 'iiiiiK) unipltts M. ami \V., and Actinocrlnus ti'iniidisrus Hall, resemble PtTiic/incrliius in general habitus, but come from a ver^- dilTerent geological hori/on, have a less elongate calyx, and pro|)ortionally shorter plates. They dilfer still more from Mijistficrimis by tl.o thinness of their plates, and by having radial ridges. These species we have marked with a query, as it is pos-

..■

t

if

11

IIAI()( UIMD.K.

521

nililo tliry nuxy liiive to lie M'|iiiruti'il HiiligciUMically, ihmIiiiix iiikIit

The amis of rirtwhrn'riiuis is lurdy nli i rvod, mihI throws no liglii on thu roliitioiis of the goiiiis. 1*. iiiiiiillifmi/iix Wiis inolial)!}' proviilcd with a cliort anal liilie, wliilo most of the olhor spocics st'uni to \\n\v had a niero jn'otnlicraiiru.

J'nirl'ciiiii.i dc Vcrncuil fl85fM is possihly iiK'nlicid wiih /V//'m7,-/c,//(im, and m1-o (iiiifiinii.i d'Oihij^ny, which was projiosi'd in (lie sanic vcar. .lohanncs Miilh'i' I'fli'i'i'i'd I'lii'l'iiriiiKi to I'ljjid'icrliiiiK, un(h'r whirh hi- pinposud to v\\\- hraci' all Actinoorinida- possessing inlerdislichals. Anifc liii i(U'nlirK'(| Trmli'i. criiiit,.i I'andei' with I', riiili"i-riiiii^ ; while Iiij;-hv look it to he a sviionvni of (if'/jilnnlnKn. The name 'J'lm lidfiinitin was pri'oci-npied hy I'orlloek in |SI8, hut 7'. /((//s, the on!}- speeies rel'erred to it. was deHcrihed I'luni an imperfect speeinnMi, ami its relations cannot !)(> aceuratidv deleinnm d. Mali's Ar/iiio- criiiiis Kiiiilf(iil!ii/i(s, wiiich is known onlv IVoni natinal casts, and which we formerly referred to /\rnvJi»rfiiiiiit, is pos»il>I_v a Murri'nliiliin-iiiiiH. S. A. Mil- ler's SdiTiirn'iiii.i ()''ir/ii/i, (yarn I)ecaiiu' Co., Ind., is dcserihod from a cast, and it is doulitl'nl if it hclon^s to this jfenns.

Periechocriniis spooiosua illuo.

J'I'l/r L. /•■;;/<. (hi. h.

IMIJ, S,i,vorrhiii V''''''"»'M — 11 \i.l. ; 1':iIm"uI. N Vurk. Vnl. II , p 2ii.'), I'liili' Ki, Fiir^i, I. i. l"''-l. /',V(Vf/(o. ■/■//(«< .vyi,-,(',,.<//j — W, iiiiil Siv ; Umi^iipii I'liliicicr , I'lirl 1 1 , |i 111.').

IJather larj^o. Calyx elonirate ; sides hut little convex ; jrreatesi widih across ihe lirst distichals; plates smooth, even without the usual radial ridges.

Hasal cup very deep. I'adials and postals onro and a half as long a.s wide, decre.ising in si/e in asceiuling order, their ujiper and lower faces exceed- ingly narrow, the u|ii)'.'r sloping Hires of the radials unusually short. Dis- tichals four; the first ahout half the si/e of the lirst costals ; the second mucdi snndler ; tiio upper ones, which are followed hy free arm plates, short ami <pia<1rangn1ar. Arms hranching a lillle ahove the calyx, and twice again higher up; lliey are proporti(mally thin and tiiper gradually to the tips. Interhraehials rather Inrgo ; the (irst followed hy (iv<' or six laiiges of two jdates ea<'h. Interdistichals in three or four rows. Construction of the anal side not known, nor the structure of the legmen. Colmnn round ; the nodal joints slightly projecting ; their cdg<'s covered with ii row of small node.",

w

S!

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l^

m

nil', CUIXOIDKA CAMKUATA (»l' NnjMII AMI.HICA.

• i

tlio.40 uf lliu intiTVi'iiiiig joiiitn .it),, il u i llio iixiiil canal citl!"!' lurgi- and circular.

JI'iitzi'H ami Liiru/lt//, — }\iajtt\ri\ .ip, iImivi- tlio filalt•^! ; Ix)ckj)oit, N. Y.

7.V/".i in tiic AniiTiciiii Mii^i-mn at Now Ytiil<

]iiiiiiiif>K. — /'. .1flldll.^<(l^, whii'li ua.H liimli' liv Hall tlii' Ij^pi' <if Siiirnrfhiiin, ii4 tlio only known Anii'iiciui J'triichuiriiwH in whicli tliu Kucuntl liil'iircatiun tiikun place in tlio arms.

PoriochocrlnuB Wbitfloldi (llti.i).

j%i, If. Fijx. J, ,'-(, /.. ,;, 4.

Hn3. .l-liiini-rimn Chritlv Ihii i 'I'liun. Allp. Iinl , Vii IV,, p. l',l(l. (AliMr., p. «), mil .{■■liHofrinui

CItfii/fi »\mi\.. Is.-j,5. ItrtS. .i.-li«;,-ri«m iriil,li'l,/i— ll\l,l ; imli Hi'|. N Y Slulc Ciili Niil. Ili«t (Dnr. K..''! ). |>. Mn 1H«|». ti,iriwfi„«» rftn't/vi — Mkkk mill WnirnitN: (Ini lli p. IIImihIk, \u\. III. p. Mi7. I'lili' .'>. I'ii;, I. ISiO. .Mi,i„rri>iitt (\Wn„-ri,i«') 11 hiljulili —\\k\\ . ■i^\f\\ \W\\ ^'' V. ISIiilr Cub. Nil, )li»l. (Uivisiil

Kil I. pp. IITllniiil I'lll. I''"'. iSinrihrinM-i Chrhlii — .S. A, Mil. 11.11 i Caliil. AiiiiT. I'liliinA. Ku'.'" . p. 90. brO, tlac,;,,;-i,int C^W.'yi — IIaii. 1 iMJi Itip. N. V, Slulc Ciih, .\ul. Ilisl. (Uiviiiil K.l.), p, 137, I'liili'

|:t, Kiif, H ii>.

19H1, Prri,vt,i,-ni4Hi f '/i,i./vi — W. iiiiil Si'. ; IIhIm,,!! I'.iliincr.. I'liil II,. p. Hii.

1881. »i,:wri„H.t (■</•/.//. — lUi,i.i mil Ami, Idp. Imliiniii, p. K.H, I'liilf U, KiK» H-^O, riulc 15,

l'in». :i, i.

A mndcrati'Iy laii^o ,«po('io'<. Caly.\ ,«iiliovati' ; tlic dorsal cnp iirn.,sliapcd, it-i siijt'M i'oiiV('\ and hut slJLditiy Hprcadiiijr ladnw tlic ai'iii liases; tlic veiitnil disk low lu'iiiisplu'rical, the platos tliin and Hal. tlie rudial ridj^o proceeding from llie niiddio of the rudiids to tlie arms rntlier oliscnre. Surface of plates finely liraniilosc, tlio granules arranjrod in e.\ccntric lines. paralUd to tlio margins of tliu plates.

Uasals largo, more nipidly spreading tlian tlie succeeding plates. Hadials nnil coslals decreasing in si/e upwards; tlio radials nearly three times as largo as the .•second coslnls. and longer than ^^ido. tlio upper and lower faces iiiucli smaller than any of the others. Distichals two. of the si/o of the sec- ond costaN, supporting two or three small palninrs, which are siicceedod hy tho arms, the structure of which is not known. Interlirachials : 1,2,2,2, Hoinotiini's with a sixth row within the arm regions ; the plates, as a rule, are longer than wide, and agree in size with adjoining hrachials. lntordi,s- ticlials 1, 2. 2; the Inwt'r one larger, resting hetween the first distichals. Anal interradiiis very wide ; the anal idato of er|iial width with the radials, hut not ciiiifo as long ; the three plates of the ,sccon(l row longi-r than wide; the middle plate the narrowest ; tho third row al,«o consists of three plates.

t

.♦<"

I (

1

!

' »

IIAKKIMXID.K.

r)2:j

t

mill Ih folloNVcil \<y (illn r low.i ol' I'im- or fix jiii'Ci'K. Wiitial (li>l» |ia\(.'il l(_\ u liir^o luiiiilici' of Kinitll, Hiiiootli, irn'^nlni' iilatcK, ii|i|iiiii-iitly willioiit ohiIh, but Hiiiall covt'i'ing iiiul xiilo |iioei>H I'littr ilic umr^'iii. Coliiniii in ui tin' cal^x coiti|iOM('(l of voi'^' hIioI'I |)ii'('c'M ; cciitiiil ciiniil nl' iiiciliiiiii Mia.

J/iifiziin (iitil Luitilili/. — Niiigiiiii gioiip; Wiilili'oii, liiii.

Ji'iiiinr/in. — J/iijinfii<riiiui iitiircniiiiiiiin iiml J/, itifitix Wiiu'li. niitl Marry, wliicli Hall liax ivgai'iluil wn iduntical will) lliin diicuicN, uio piolialih difliiict.

ForlooboorlnuB maroouanus (Winmi. -mA .M\ii>>).

Vltitf I., l-'iiju. ill, li, iinii J'lii/c LI. Fi'l. i").

ISnj. Mrr/i'/<uviiiin w.(/-.v,«,M«— WiM 11H.L liiiil MAli(»i Mhii Itinlull Ka', Nut. Ili»t., Vil. I, \l S7,

I'l.ih' II , Kit.'. 5. l*-?!), Sni. iif .V,/,rt/,Y(»«. r^W./y/ — IIai.I. 1 iiSlli |(,'p X. Y Slntr Mm- NiiI. Ili-I (Itiii-il I.I ), |., l;';. l'*S|, UMi'iiCtiiiHt uiiiri'timiHua — S. A. .MlLILii ', Juui'ii. Ciui'iii. Sm'. Nul. |li>l., Vnl. IV., p. |t'>7, riali' 1,

V'i«», I, li/. Iss.'i. /'.■(■iVi'<"i-/'i«».i w,/fi'.(«//«((<(') — W. iiimI Sr. i llriUimi I'lilii r., I'ml 111,]' lufl

A vi'ry largo iiiii] I'longati! H|ii'fii.'.M ; tin- calyx hioiiR'tinu's rt'acliing a lon^'tli III 7'') iiiMi. I)y aliiiiit III nun. in wiillli across Ilic arm liases; form Hiiliovoid, the wiillh greatest ill tlio top of the .si'coiul costals, v hence it con- tracts to the third di.slichals, there ex|iaiidiiig again to the arm hases. Inter- lir.iciiial and int'rdistichal areas soniewlmt llatteiied or faintly dipressed, prodiiciiijr a sort of angularity along the median line of the radial series, wilhont forming an actual ridge until close to the arms. Sini'aee of plates smoiith, the sntui'o lines not gnxtved.

IJasals comparatively small, forming a Hnuccr-sliaped, hexngoiial cnp. ]{adials and costals of nearly the same hize nnd of similar f(>).u, their lat- eral faces concave to receive the convi'X sides of adjoining inierlirachials. Second costals as long as the lirst, and neaily as wide ; the upper and lovier faces in hoth of them narrow ; the upper sloping sides longer than the lower. Disiiclials three, decreasing in si/e upward.'; the first nearly lis long n.s the costals, and almost as wide, its upper face (|nite narrow ; the second of the same proportions hut smaller; the third much sh(M'tcr. Paluiars miineroiis. c'omparutively small, shorter than wide, those of the same divisions in later.il contact. .\rms lour to liie ray, arranged in pairs; their lir-t hifurrations close to the calyx. Interlirachial sjiaces long and narrow ; they consist of one plate in the first row, followed hy from ten to twelve ranges of two jjlate.s each, which meet the jilates of the tegmcii. Aiml interradius very wide ; first nnal plate a little shorter thnn the radials. hut wider nt the upper face ;

■«»

•31' I

Tin; tUIXOIDKA C.VMKUATA C)l' XORTIl AMKUK'A.

.i

tlie tliroe jjIuIl's uliovo succecilod liy throe plates, and iiuiiicioii-^ otliur plates inegiilaily arranged in rows of lioin live to six pieces eadi, wliicli grow smaller as they approach the teginen. Upon the ventral disk there is a well defined anal ridge, which ends in a snijcentrul proboscidilbrin protuherance ".villi the anus at the upper end. Interdisiiclials consisting of a rather largo plate re>ting hetween the sloping upper faces of the first distichals, and six or more rows of two plates each, the upper ones resendjling the plates of the tcgmen. Tegmen almost Hat ; comi)osed exclusively of .small polygonal plates. In the casts there appi'ar upon the surface ten well marked ridges, which re[)resent grooves in the test for the reception of the nnihulacra,

If'i-'con mid L'iriililj. — Upper part of Niagara group ; near C'liieago, Ills.

Ill iKdrl'ii. — It piol)al)ly occurs also at Waldron. Among the specimens which we refer to it there is one in wliicdi large jiortionsof the arms are pre- served. The\- hrancli at aliont 18 mm. above the calyx, and one of the iiranches again at aliout li-") mm. above the first bifurcation. Whether any ailditional bifurcation takes place in this species, cannot lie n.scertained, as the arms arc broken at 0") mm. from the calyx. The arms are composed of two rows of short, transverse pieces, very regularly arranged.

P0rioc?iocrinus necis (Winmi. ami Maiuv). Plate L. Fii/n. la, h.

Isf,:, }[,-ii,l„e,iiiii!i «»•.■/,< — WisniKi.T. .uiil MuK V ; .MciM Hn.-!. Sne, Ni,i, Ilivt., p. 111). I'lMr 2, Pii, fi. bil. .SV. ■■■«•/ /««s «(cis — S ,\. Mii.i.KLi; .liiuni. Ciiiriu, Sw. N;ii. lli>l.. \ ul. IV., p. I'ri, Vhw \, Figs.

;!, -ill. ISSo. 7',v/r r^M.TirfM «/W,< — W. mill Si'. ; liciMnii riiliini-r , 1';ul III.,]'.lO0

A shorter species than the preceding. Calyx pyriform, not much higher than wide ; obconical to the top of the second radials ; greatest width a little above the second costals. whence it contracts rapidly to the arm bases, at which the calyx is reduced to two thirds its former width. Surface of plates siiiooth. wiih slight angularities following the radials, giving to the cross- sect i(jii a somewhat pentangular outline.

liasals of niedimn size, more rapidly spreading than the parts ainvo. IJadials and costids occupying two thirds the height of the calyx, nearly of C'lual size, longer than wide; their upper and lower faces wider than nsnal in this genus. Distichals two; the first plat o one third smaller than the costals; the second as much as one half Paliuars two or more, small, and between them are interposed 1, 2, 2, small interdisiiclials. Inteibrachial.s

IJATOCUrMD.r..

525

ratliur liirge, (lecronsiug gnulimlly in size ; disposed geiieiiilly in six rows, of wliieli tiie iippei' ones are iiiegulai' and not readily reeognizcd; the first jiliilc, whieli lias tiie size of the first costids, snpports two jilates in tiie second row, and tiiree in tiie sueceeding ones. Anal iiiterradiii.H wide, tlie first anal plaie a.s hirgc as tiie radials; succeeded liy tliree plates, the middle one the smallest, and four or five plate.>! in tiie rows above. Tegnien almost Hat. its diameter remaikahly .small, owing to tiie constriction at the upper regions of the dorsal cup. In tiie casts there are no traces of dislv aml)ulaera, and iKUhiug to iiiilicate tlie presence of orals in tliis species, the whole sml'ace is covered by tlie impressions of small, irregular plates, surrounded liy what appears to represent tlie arm oponiiins, which were apparently arrangecl in groups, forminjr a circle around the disk. Tlie exact iiumhi'r of primary arms could not be ascertained from the specimens, but wo have reason to bilieve there were eiglit arms to the rny. Anus subeentral, apparently not large.

Iluiaun and LomlUj. — Upper part of Niagara group, near Chicago, Ills.

1^

Periochocriaus infelix (Wimh. mid M.Mtiv).

I'lilli L. /Vy.s. .^^ h. c. -1.

1^05. M,'jiHln,;-i,iii< i,if,i:.r~ WiNi Hi i.r, .■u.,l \l Mi. \ ; Mnii I!h-i. S,,,-. N:lI. Ill~t„ p ll't. I'l ,1,- 2, Fii.'. 7.

l^^;l. S.vii. nl' ,V,w-"-/-/,i«.< r/,//./y/— IIai.i.; i^y\\ Itcp. N. V. SimIi' Mil-. Niii. lli-i . p. IJ7.

1--S1. Siimc.iiiH.i i«f/ix — S. A. .\lii.i.Ku; Jiiuru. C'iiiciu. Sic. Nm. lliM., V.,1. IV, p ;ir,il, I'luli' r,

i'i^'s. i, ii, h 1SS3. Perirrli,.,vi,im i,i/''lij-(;-) —W- uml Si'.; lii-\i«i.iii I';,l;i'uii- , l':iil 111.. |i. lufi.

H\». Siimci-iiias li;/iiiii — -A. \. .Mli.l.Fli ; Jmini. Ciiuiii. Shc. .\al. Iliji., Vnl. IV, p, 17:i. Vliil'' I-

Figs, t, y.

Smaller than the two preceding species. Dorsal cup somewlmt obconical. higher tli.iu wide; sides conve.\, abruptly spreading from tlir ba.sils to the top of tlie radials; the upper regions almost cylindrical, sometimes a little spreading; surface of plates sliglitly convex, and covered willi obscure radiations.

IJasals small, forming a shallow pentangular cup. l!;idials ami co^tals rising to tlirec fourths the height of the calyx : tlic radials much wider than the lirst costal.s. about as wide as long, and the sloping upper faces almost as short as tlie upper face; the first costals. as a rule, a little larger than tlie second. Distichals two. one third smaller tliaii the preceding .•ixillary. I'al- mars two, small. Interbrachial ami interdisti<'lial areas .Himeuliat grooved at the upper ends, l.iterdistiehals disposed in six to seven row< ; the first as large as tlie first costuls, with obtuse upper angle and long lateral laces, great-

i .1

^

>J2G

TUK CUINnlDKA CA.MKUATA Ol' NOUTII AMKUICA.

1

'II

est will ill iiboiit one foiiitli its lii-ight ; siiccccdiiig iilutes in rows of two, tla- iil)|)er oiU's siiiiiil and incguliiily iirranyed. Anal intornidius wide, de- pressed between the arm bases, and forming at the ventral snrlace a I'onnded riilgi'. wliicli connects with the anus; the plates very numerous and irregu- larly arninged. Interdistichals generally 1, li, Ll. Ventral di.-U low-convex, the inlirambulaeral spaces depressed, the plates nearly Hat. The food grooves in the cast are delinciited by prominent ridges, which bifurcate half wa)- out to the arms, and again close to the arm bases, giving olT in tiio calyx four arms to the ray.

JInil.iiii (tint l.oviililij. — I'pper part of Niagara group, near Chicago, Ills.

liihini-ks. — Tiiis species was regarded by Hall as a synonym ol' I'lriich"- rriiiii-i W'liitlklili, iiiit we agree with Miller that the two forms are distinct. The jilatcs of /'. W'liiljii Itii are llat and limly ornamented, those of 1'. in/ili.i- convrv ami without ornamentation; the radials of the former possess promi- nent liilge-^. whiih are wanting in the other. We disagree with Miller, honever, as to hi.s •• S('iiin-uiiis" h'l/iini. which we take to be identical with P. //;/;//.(•.

Poriochocriniis urniformis (s. A. Mn.ni.). I'ia', L. Fi-js. .',„. h.

l^^l, .V„'.v,rv(/i».i »,v//;.,vi/. — S. A .\Iii.i,i;ii. .I.iulii. Iniilli Sic. N.il Ilis| , Veil. IV., |i. !7il, I'hitc i,

l*^"'.'). /''■rt'r/i"rnfitt!i Hi-tiifhriitit {'■} — W iiint Si'.; IttM-inu I'ala'opr.. I*:ni 111 . p llU't.

hMi. .SV/.ri<vi'i»« /'»'■'/'"■""'' — ^ ■'^ .Mii.i.i u; l^^i', .Imini t'iiii'in. S.n-. N.ii. H\>[.. Vi.l. V., |.. ^l,

I'l.iic ;i, Ki-. .i

Smi. I>,n.r/,.,,;i,„,> ,, ■,.■;,■■.,:.,/, (■■) — \\\ lui.l Sv ; l!,M-i..M I'l.Iii r., I'.ir; III . p. lull.

Only known from inlcriiiil casts. ('aly.\ large, o\oid; greatest width arro-« the .11111 ba>es, which are somewhat projecting; plates gradually lii'cira^ing in width upwards.

ISa^als small, forming a rather low cup. Hadials anil costals nearly of ecpial -i/e ; their width actus- the middle I'cpial to their height; the upper and lower faces less cou-^lricted 'ban in the )ireceding spccli's. I)i.-tichais two. the first one fiuirth. and the >econd as much as one half, smaller llian the (ostal axillaries. I'lilmars two. small. Interbiachial and iiilerdislichal areas on a level with siinoundiiig lirachials. cNcejit close to the arm bases, where they form rather wide, well marked depressions, which ai'i' conlinui'd upon the tognien. l-"ii>t inleibrachial of about the s;mie size as the first costal, but pentangular in |i!ace of he.\angnlar; succeeded by si.\ to seven rows of

t

r

«>

n.VTOCRINID.E. 027

two jiliites ciicli. Tntprdistidinl", 1, 'J, 2; the first rcslinj^ within tlie iiotcli of llio first (listichiils. Anal .xido rciiiarkal)!}' wide. The nnal phite, whieh elosely resembles tiie radials, followed hy three raihiT larjie ])lates, and tiiese h^- three smaller ones and an eloni^ate plate at each side, wiiicli latter rise to the top of the plates of the third row, so that tin' seeond and third rows to- j^ether eontain eight plates. This arrnngement, however, is not invariable; tiiere aic some speeiinens in which these rows have live plates I'aeli. and the plates above, on approaching the tegineii, Ibiin u ronndcil. conspienoii-: ridge, whieh conneets with the anus. The course of the and)ulacra is indicati'd in tlie casts by well mark('(l riilges, whieh branch twice njjon the surface, and show that there was tx third bifurcation in the ealy.v. ^'entral di.-k hcnnspheri<'al, composed of rather uniform pieces of moderate size. Anus sul)eeulral.

llar'nan nil'/ J.dciilili/. — Upper part of Niagara group; Chicago, Ills.

Jii iiiiii-f,:f. — We have carefully eoniparcil Miller's types of his "Siii-rn- criiins" jii/rifiiriiilii with the types of Pi riirliiii'riiiii'< iii'iii/'iniiis. both in the colleetioM of Mr. Kgan of Chicago, and came to the conclusion tiiat the dif- fei'cnei's i)ointed out in tlie descriptions are not constant, and are to a large extent imaginary,

(?) Periochocrinus ornatiis iiiAn).

PMr L. Fhj^. .!,i. /,. mil/ r/air 1. 1. Fill. 7.

b7"). Sdi'forriim* l)niiltii!i—\\\\.\.\ (ii'ii lirp Oliin, l';ilii I , Yc.l II , |l. 1311, rl;ili' ti, Vii:*. * In 0.

h^l. yV,/.v//././7««,« onuiliif— W, mill Si' ; Iti'vl^i.iM I'liln '., l':irl II.. |i. Y\i.

Svii. S,n;-n,-ri,iin H,nrf/lrfi — S. A. MiMiii; I'-'.IJ. A.lv Sh.il- l>>ili Hi|i (n"l Si[i-v, lii.ll:inii, p. i'.i. I'liiti' .'i, Kins. 1 ami -2.

A snialler spi'cies than the jireceding one. Calyx oboviite ; the dorsal cup elongate urii-sliapcd. obsciu'idy pentangular in tiic upper portions, the rays at ilie arm bases widely separated, especially upon the posterior side. Plates liighly elevated, subconical. with deeply cliaini(di'(l suture-^; the smfaee cov- ered with c,)arse rugixities or irregular protuberances, nieeting in the centre of the plate^'. and jia-sing out to the edg(>s.

Basals rather large, forming a moderately spreading cup. Tladials and I'ostals higher than wide, gradu.ally deiM'casing in si/.e , thi' former consid- I'rably larger than the eost.als. Distichals free from above the third plaie. Arm structure unknown. Interbrachials in five rows; the first plate ns large as the first costal; there are two in the sccoinl range, .iml live in the three

i

■ f-i

i-J8

Till- < KINdlDKA ( AMKliAIA Ol- Nolilll AMKUICA.

\

,1

Ml

iil)|)i'i' oiii's i(p;4ciliiT. iIk' liitli'i' iin'ciiiiL!: till' ini('iiiinl)iilii('iiil jiit'ci's. Intcr- IjiucIiiiiU a|ii)iiii'iilly lliioe. \'t'iitiiil <li>k riitlRT ili'pri'ssiMl noiir llie otitov iiiargin ; tlic ciuti:!! iimtidiis ijradiiiilly \\Au'^ to u good-fi/fd !iii:il tiilic, coniposi'il 1)1" iiKKliTiili'ly liii;;!'. ('oiivi.'X jilatis siniiliir to tlioM' fdriMiiij:' tlio

tcgllU'll.

J/"ri:.iiii ihiil l.''inlihj. — Niiigiiiii groiiji ; Vi'lluw ^iniiigs, ()., ami St. Paul, Sliclliy Co.. Iiiil.

//';//<'< /.*.-- Tliis s])ecit's (Icpaits from llic otliiM'.s in liaviiiLf a large nnal tiil)i'. a cliaracliT wliicli in ollior groups \\\\s Wvw ifgartli'il ol gcnorio ini- portaiicc. and we >l]oiiId |iro|io-(' I'or it a new ^cnus if wo wt'ic better inlorniud as to liie anal slrucliMu of ilio oilier spccios.

Pericchocrinxis tenncsseensis (IImi).

rint,' L. /•',,/. ,;.

I ^.'»n. !^tit'i'(n'nnii!t hnn>\<iit'iH'^\s -' TltnuM MS.

1>.;.), .V,„v,»VM«.. /,■//«,■..,..,■,/./.— 11 or; (iciil. II, |). (Il.i... r;.|.i-.M,i,, A',,1. II.. p. IJ",. I'l:,l|. fi. Vir. 10.

Svii .V/c.-i..v/>(»t -/)T(./..«s — Uuno.ii (mcjI 1I.\1,ii; Silur. I'iiiiiiii ili» Wi^ll. 'J'l ini , )i. k'. I'liiii .'I.

or llio type of /'. -yz/r/.o/'.v IImII, ImiI tlic lliird division of cacli ray taUcs placi' 'n tliu lalv.x and not in tln' arms; ami it lias twrnly primary arms in plai'f of ten. 1 loisal clip cloiiiialu oliconical. one lomlli liii:lii'r than wide, sligliily intlatcd at iwo liiirds its lu'iglil. Arm liasi's ('on<piciioM>ly projccliiig. diH'ply dcjiri'sscd i.i'luiH'ii the rays and llieir main divisions; the depressions of the anal side \\ide>t .ind deepest. Surface of jdates smooth, willi a faint longitudinal elevation aloiiLT the radial series, which at the toji ol' the diii.^id Clip widens to iho lull width of the iiniis.

I>a-als rorming a soinewhat conical cup. Hadials mm h larger than the eo-ials ; ihe latter coiisideiahly narrower, and hut little longer than wide. Di^iielial' Iwo, half the size ol' the jireeeding a.\illaiy. as wide as high. I'.il- mars still smaller, rounded like arm jiliites. ,\rius thin. e\ lindrical. ananged ill pairs. I(i>erial Irom their origin. Interhiaehial areas composed of (i\e or si.\ rows; the plates anaiigeil as in the jirecedilig sjiecies, inclmlilig those ol' the anal side. \'eiiti,d di-k constructei! of a iiiiiulier of polygonal plates without delinito arrangenieiit. Anus suljceiitral.

H"rr.''n mil) J.'<-'i/il'/. — Niagara group; Dicalur and Perr}" Cos.. Teiin., nnd Yellow Springs. ().

Ill iiiiiil-x. — Till' typo speeiinon, colli eted hy Dr. 'i'roo-t. came from I)e-

') I

n.VTOCUIMD.K.

o2U

patiir Co., Tfiin., find tla-re is but lidlu (loii])t timt the one dcscrilicd by Hoemcr, iiiul iirovisioniilly rL'lLMTL'd by liim to San-iirriiinn .yicrid^ns II;ill (Siliir. Fiiiiiift West. T'.'iiii., Pluto 3, Fig. .I), ie|)re.s('iit.s tlio same species. We Iinvo ill our collection sevonil .specimens (Vom that locality with I'onr arms Id omcIi rny. but none «illi tliree in tlic posterior ra^s, as shown in Ivociiier's (ijriiro. wliicli is saiil to bo a restoration. Tlio specimen described afterwards liy Hall is ft natural cast in the Ohio State Caljinet.

1 ;

fc^jh'

Periechocrinus Howard! (S. A. Mii.i.rn).

I^lli. ,V</.-a«t///m //.y/ran/i — S. A. Mll.i.ili; Adv. Sliwls l^lli Ucp. fli'dl. Suit., Iii(li;in:i, p. .W, I>1„|,. r,, Kins. ;! iiiiil I-.

A small species. Calyx liii.;her than wide, broadly trimcnted at the liasc, ami l)iit slightly oxnanding, .so as to \)v almost snbcylindrical to near the arm l)ascs, which bend al)ruptly outward. Plates tumid, without oriiiimen- tation ; suture lines beveled.

Baso short, forming a broad rim, which is srpiarely trnncated at the bot- tom ; its diameter e((ual to two tliinls the greatest width ofthecii]!. Hadials more tumid than the other plates, about as wide as long. First costals two thir<ls the size of the radials; the second much smidler. Disticlials three, directed almost at rigiii angles to tlio axis of the calyx ; supporting tlie fiee arms. Ann openings ten, arrangeil in pairs, each pair separated by numer- ous iulcrradial plates, which connect with the plates of the tegmen. Inter- railial areas composed of two or three largo tumid plates, followed by smaller ones. In the type specimen there is but one large jdate in the second row at the regular sides, probably the usual two being consolidated. Anal area much wider and somewhat flattened, the plates rising almost vertically. Anal plate followed by .'!, .'J, and ■") interbrachials , tho<e of the liitler row irregu- larly arranged. Ventral disk almost or a level with the arm bases, only the central part a little convex ; couiposed of numerous small plates witliout defi- nite arrangement. The anal opening marginal.

Ifiirhrm iiinl Jj'iriih'///. — Niagara group; St. Paul, Shelby Co., Iiid.

/(■d/xo/n. — Heing unable to obtain the type specimen, our description i.s made after Miller.

^ 1

4" •■

er

S.'

I '.I'

G30

TIIK CUINOIDKA CAMKUATA OK NOKTII AMKUICA.

is;;) ih;;

(••) Periochocrinus Whitei (il \i,i.). rf'itc XL 17. /Vys. J, J, o, <iwl J'hil, LI. F'igs. 0, 10.

.irlimi,;iiiii' (Mi'ii.x/oi-iiiiii') ll'/ii/et — 11.V1.1. j I'lilini Disii. .\i» I'liii., p 2, mill l!(iil Jwirii. Nnt.

iiiM., |i. i;i.

Mi/hlifi-iiKit (Stitviii-riiiw) iriiilti — Mkkk nml \ViiUTili.N ; (irul. ltr|i. llliiici!., Veil. V., |). H'J7,

I'luli' li, Fil,'». 1./, 4, <•• .\/yith„;-itiiit U'/ii/ri — S A. Mll.l.KU! Amcr. I'lilii'nz. F"»h , |> SX l'l>^l. l'ri-i:vliurriiii:.i H'^iV.) - \V. iiiul Si', j U. v;»iiiii I'aliiuiT., I'liit II, |i 1.1:1; iinil Wliilliildj Amcr. Mils. Nut. Ili»l., IMCI, V.il. I., |. il, i'latc- !i, li:.-. ■-".). Syii. .li'liHoi'i-iiiKt {I'r.il.i.-riiiii') ui.iiilii' — Mki;k nml WiiuriiKV ; Isi'il. I'n.r. Aciiil. Xiil. Sci. I'liilu , |i. i:i:i, iilxi l'>i'iH, iii'.il. |{i'|i. lliiiiiii.4, Viil. III., |>. 1711. I'luii' li'i. KiK. i.

&\ii. .l>-fiitu<-i'ifiMi in,ii>lini — S, \. .Mii.i.KK; .\m('r. I'nliri /, Ku'-s , p. (Wi.

Svii. I'rriifhurriiim (liiiiihi) — \V. iilul Siv ; Hi'visiini ''iiUnrl'.. I'liil II., p. 1,'U.

Calvx (U'pi'u-sid boll-sliii[)0(l, lieiglit niid gieate.-it widtli nonrly of|Unl ; li'giiu'ii tliitti'iii'il or (K'|ii-t'ssi'(l convex ; [liatos tliiii, ami williout oi iiiiiiiciila- tioii; radial ridge hut iiiiiilly iiiiiieated.

IJasal.s fonuing a .•^liallow Iia>iii, aluiiiillv tniii('at''d at tlie liottoiii lor tlie reci'iition of the ti)hiiiin ; liie latter onupviiig two tiiird.s the diameter of the \n\<i.'. lladial.s large, !.'nglli and width suheijual, their uinier lateral faee.s shiirter than the corre-iioiiilin-' Uf-.vei' oni's. J''ir>t eo.^lal.-i searecly more thiin hail' tlie .-ii/e of the radinN. [jro|iiirlionall\ a litlle longer, and hexan- giiliir; •■iecdud c'l-tal.-* niiu'h .^iiialler than the lirsi. and |iinlangular. The laller ^^'piiorl lour di.'<ii(dial<. uliieh acrordiiig to the age ol the >iiecMMen are I'illier all li\ed or in |iart free. The distichals >hort. even the rM>l \\liieh i.«i twi'o as long as the succeeding ones. Arm facets jirojecting, arranged in pairs, the s|ia(.'es hot ween tiic rays Iwici as wide as those latwcen ihcir main ili\i>ii'ns. Arms long, gradually decreasing in .siw \ipwards, very dtdieate at the toil, liiserial aliovi' the lirsl to ihc third di.«^lichal. Pinnules long. elo>e]y packed and rather sioui ; their joints twice as long as wiile. Fir.st inter- hraciiial as large as the lirsl cuslals or larger; .sujiporling two ^nudler plates in llie -ecoiid raiiLii'. three in the third, ami a nundier of irregular pieee.s alios e. Anal interradins very wide; each one of the three plates icsting upon the first anal almo-^t as large as the om' plate of the regular sides, 'i'hev are rollnwcd liy ihrcc smaller pieces, and these in large specinu'ns hy as much as twenty or more iilates, of which the uppi'r row ronneet.s with the plaU> of the legmen. The disk plates are ."mall ihrouglionf, and closely rc-emlile the interamliulacral ]ilatcs df some IV'iitacrinidie. Anus excentric. rising hut I'lile above the gemual surlaeo of the tegmen. Colmnn >lout, the joints

L\

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4

llAKK UIXID.i:.

r,:'A

(|ultu imifoiin ; tlicir upper imtl lower fiiccs striated nt tlie iiiiirjriii, mid Hiiiuutli ill tiie iniiiiliu ; Mxiui caiiiil of iiioileriile si/.c.

Jfuriiiiii iiwl L'lfii/ih/. — 111 tliu Kiiiderliuok group nt I,e Ci;iii(l. Miir>liiill Co., low:), niiii ill liotli iliviHiuns uf the liuiliiij^loii group tit liiiiiiiigtoii iiml other phices.

Ill iiiiirhx. — There eiiii he no iloiiht liuil tlie siieeimeiis of the tiiiee heils represent one ami the same species, althoiigli ililTeriiij^ eoii^iilerahlv in size. In tiie Kiiiderliook j^roiip the ^peciiiiciis are siiialier. mid oiilv a single dis- ticlial tiikoH part in the calyx, wliile in tin? liuiiington two or three of them are incorporated, miil the specimens have proportionally more inteihrachial plaled.

(") Periechocrinus tenuidisciis (IImi.'). rial, XI A I. l\i. ,;. „//./ I'hW LI. h\i. (].

l^fil. C) Arfiihif-riHiix Irmihhvnx— II M.I. ; riiliiii DiHT. Nrw Crin., |i 1 1. X^'iT . .IrtiiiiH'riiiiin iiiiniili'f^ii — S. .\. .Mii.i.m; Ciitul \'An-,\i. F""-.. |i. r.s.

I'l''!. I'niii-huri'iilllH ICilHill'fua — \V. llNil Si' ; Itc'vi"!'!!! I'illlllPl'r., I'iirl I!., p l^H.

Clo-ely allied to the ])receding species, and ])eiliaps a mere variety of tli(> Hnine. Dorsal cup more compressed, and distinctly rounded, llie arm liases less projectini;, mid the plates ornamented. 'J"he plates of the dorsal cup ciivere(l hy lii'oad, ili-iie(iui(l ridges passing out fioiii near th<' middle of the plates to the margins, wlieie they meet the ridges of adjoining [ilates. The ridges lollowing the hraciiials more prumineiit. especially as they ajiproatdi the arm liases. A similar ridge follows the nu'dian line of the anal area. Tlio surface of the plates is heautifully marked hy very fine r.idialing wrink- les; the pl.iles very tliin at tlieir outer iiiargins, and hut little thicker in the niid<ile.

IJasals fiu'iuing a low hexagonal liasin, w ith a slightly projecting rim at till' hottom ; iho culiimn facet somewhat conc.'ixt'. occupying one half the diameter of the eiip. liadials large, nearly as long as wide; the coslals eoii- siderahly smaller, decreasing in size n|)wm'ds in the same jiropoitioiis as the radials and fnsl costals. Histichals. so far as ohserved. two or three in the calyx; the two upper ones curved like arm plati -. First inleihiachial as large as the lirsl <'o-:lal-. and as wide as long, those ot the second rfiw eipial to the second cost.'ds ; the second row has two or Ihi'i'c i)lales, and the succeeiliug ones tliri'e (u- fiuir. Anal inleriadius very wiile; the Inst anal jilale smaller than tlie radials; the tliree plates overlying it as large as the first inter-

S,(.

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TIIK CiUXOIDKA ( AMKRATA OK NORTH AMKKKA.

liiiiL'liial of till" ri'giilar sides; siiceetMliii;,' rows goiuMiilly contdiiiiiiy: five jilutt'8. Inlerilistii'luils one. Stiiictuie of toj,'iiien niiil nrins not kiiitwii.

llori'iiii liiiil [.nrnlit'/. — I/iwi'i' liiiiiiiigtoii liiiR'stunu ; Ihirlingtuii, Iowa.

y^//(' ill tlio Miisi'iiiii ol' CuinparatiM" Zoiilogy.

i

\

I i

MEOISTOCRINUS •>. anl Sm m

IS.-iJ. Oivttv aihl Shi Miiiii; I'. S. (ii,.l II, p lowii, \Vi>c. :iiiil Minn., p 5'.H.

IS.tS. Ilvix; Im'oI. Iti'p. In»n, Vol. I.. I'lirl II., p W.

IHIUI. .Mmk^ui.I WniiniKN, I'rnri't'ii. .Vi'imI. Nat t«n. I'liilii, p. Il'<3,

W.\. MltKlllul W.JHIIIIN; (l.ul llrp lllill..i». Vol. V. p iUKl.

1S7U. /.iiiH.; II.iiiilli. >l<r I'alii t , V.il. I , p. HTI.

issl. W. nnJ Si',i llivi.c..ii i'lilunir., I'ail II., p. l:l.", (|'n«v .\™l. Niil. Si-I. I'liil.i , p. IKl'.l).

1»'.KI S. \ Mlll.KIl; Nnrlh AllllT. (iriil. Ullil I'llln'nllt.. p. i'l'id

Spi'oiiiiL'iiH ijiMierally lai'Ljc ; tlio calyx (lc|iri'ssoil, wider tliaii liigli ; (liitti'iu'd on tlio l)utU)iii, ami soiiictiiiu's excaxali'il ; tlii' jilali-s livavy. I!,i*;ds tliit'c, clo-ifly aiidiylosed and not divislMc. I'orniiiij,' tojit'llifr a liiii'lt iif.\aiij;ular plalc, pieirod liy a larj^o canal. Itadials gi'iu'iidlv .-pruad out liiiii/oiitally. widor tliaii loiijr. and all iicNaginial in oiitlino. t'ci.-^tnls of a -iiiiilar I'onn in tlie radials, mid alnni>t as larj^c. 'I'lic nunilicr of iiiin liial.s piiilicipaliiii,' ill till' fiilyx is <piite vaiiaMc aiiioni; tlic spi'cics; in ^nnu> of ilii'iii till' ray.-i are fieo from idiovi; tlic> dislii'lial.-^, wliilo in titlier.'' piilinai's, Miiil I'xccptionally post-]>aliiiar-', an* incorimratcd. Anns hiscrial lliroii^h- ont, Inancliiiiv', and jmidiially diiiiinisliiii;f in si/c upwards. l'iiiiiiik'.< small and randy prusorvi-d. Tlii' I'ood "^rotivcs of tlic arms rovcii'd liy two row."* of covi'iiiii,' jdatos, iMMiU'i'i'd on cacli sido liy a scries of well didincd side pieces, wlii(di in some s|)eeios enter llie tci,nn"ii. Iiilcrlnaidiials niiiiierons and in contact with ilic iiiteraiiilnilacral jiicces. Anal area very wid"; the tlii'ee plates of the (iist iiilcrln'aidiial row larj,'e. and ftdlowcd hy several raiijjfes of iVom loiir to six |)ieces. Ventral disk low lieniispliericiil. tlic orals and radial dome plates often i'^olated liy small peri-omic plates. wlii(di increase in niimlier with the jrrowth of the imlividnal. Anns exccntric, sometimes niiir<.'inal. ('oliiiiui very lari^o niul loiijr. with strong cirri at the distal end; the eciilr;il cantd wide and pciitaloliate.

Dishilii'li'.ni. — This e-cniis appears in America in the Cornifcrons, survives the Hamilton ami Kiiiderhook groups, and disajipear-: hcforc the (dose of the rpper nniliiigton. In Knrope it is prolialdy reprcscntcil hy •• Av/inocrlinis" fjlii/josiis Phillip-, from the Monnlain lime-tone of Knglaiul.

T'/j>i' of the genus: Miyiatiifrliiiis KcnnsL

I

HATorniNin.K.

688

III iiiiiil,". — Wo lifuo not lit'cn iiMc to ir.icc llic type uf .Uiiji.stiirriniis h'liiijijii, liaviM<; ^'^'ll^^•llt'^l lor it in viiin in llif KiKipi) collcciion at New I'roxi- iltMicc, Iml., anil in llic F.yon colli'i'tion ; anil we oinil ili'sciiliin^r it, as tjiu lijfurt'H in llio I'ioccimI. of iIu' Soc. Nat. S<'i. i'liila. are nunu'wlmt nii>l('ailihg.

'I'lii' lirancliinj^ of llic arms in llii-ir Itisi'iia! stati'. wlii'ri'iiy tiiiMi' iiro two rows of interlocking joints Itelow tlic lirst bilinvation, as it iicfins in lliis Hriiiis ami in /'iiiirhiicriiitin and AliucdcriiinK, is \i'iy (■liMra('li'ri>li(' of llio tinx'o genera, wliieli are otiierwiso well distingnislied IVcnn eacli oilier. This arm strnelure oci-nrs also in Ar/iiinri-iiiiix wlicii tiiere is ii bil'ureatioii beyond tiic ealy.\, and in some of tiie Klioiloerinidie.

''I

Mogistocrinus Evansi <>. miuI sm m. J htif XL III. Fiijs. /,(, />, Jit, /'. J, ',11. /., .',,1, h, 0.

ISr.O. f)«KN mill Sill MMlh; .Inlini Al'llll. Nlll. Sl'i, I'hil.l., Vnl. II . |l M.

b.'ii. II«K\ iiMil Smi Minis r. S. (ii'ul Siiiv. WiM'., liiMii mill Miiiti., p .V,ll, ri^ito 6./, ?iif!<. 3./, *.

I^^l. \\. :ui.l ><r ; lltvi-i.Mi I'liht r., rml II., p. |.'I7.

Svii. .l,-liiiii,Ti,int /lO'vii'wai.t — IIaI.I. ; IS,>, (icnl. Hep, IciMu, Viil. I , Pari II., p .',71, I'lalc In,

Kiir*.. ^/, A ( l//v//t/«.T///«.» fnrvii'oniii \\ , mill Sp ). 8vil. .IrtiHiH'riilii' imiii-rliilH'— ll.\l.l.; l'>.'iS. iliiil,, p hri, 8vii. .{'•fiiiofi'iiHii iiiiH'ir — 11 0.1. ; H.')*», ibid., p. 5,3. Svii. M,-,/i.,t,„;-i,i«.< i,/i««< — WiiiTK, I'^lri, I'ri.i-ccil. l\u>t. >i,n\ Nut, lli-l., Vi.I. IX , .\pril iiiiiiiInT

(\iilli<>r'> Kil., p. Hi). Svii. Mfyl'>'i''riiii4.i iaii-vi,„.</ri.' — Mkkk iiiiil Wniniiv.N ; l»iill, I'rnc .\c:ii| Nut, Sci I'lnhi , p, lll.'i, mill (ir„l. 11,'p. Iljiunl^, V..1. v., p itllil. ri.ilf I), I'ii; 7.

Attaining very large si/.o. Calyx wider than liigli. Inmcated to near llie top of the radials ; hasi-rudial siitines broadly and deeply channeled ; basals more or less depressed, rarely rising beyond the plane of the radials; sides of the dorsal enp evenly spreiiding to the top of liie costals. and more abniplly thence to tiie .arm bases. I'lates lieavy. a little convex, the surface smooth or slightly corrugated, the sutmc lines deeply eamiliciilate.

Hasals closidy ancliylosed ; horl/ontal. roimded off toward the basi-rndial sutures, forming a nearly Hat hexagon pi(>rced by a large pentalobale canal ; the colmiin occnpying aliout one half its diameter, liiidials w ider than long, all hexagonal in outline; their lower faces ])arallel with the n]i|ii'r; upper and lower sloping faces about eipial. First costals hexagonal, as long as the radials, but somewhat narrower; iho second simdler and pentangular. The axillary costal supports at each side two large disticlials. followed by palmars, of which the two proximal ones at either side of the axillary are nearly n.s long as wide, coinpuratively large, and tlioso of the .same ray interlock at

M

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4

M\

IIIK ( IflNUIDKA r.VMKHA.v (»l' MHU'll AMKUIt'A.

ilio iinii'i' nidi'?*. 'I'lii'^' lire .tiici'i'i'dcil in I'lill giowii ^llt•(■illl^■tl- li\ two scrii't of i>liil(>M of lliu wniK' onliT, wliiili to the litdi or wixtli mws lUe iiicoiporntiMl into ilii; ciilyv. 'I'lii'ic iiii' ttii [mir,-* ol very liirgo arm ojieiiiiijjM iliii'ctid iipwiiiili, 1)1' wliii'li lluisi' 111' the mum puii' iiio coiilijriioif, wliilc tlio-c of iiiljoiiuii;^ pairs are piacotl iiparl. Itt'iiij; Hopariitcd liy will iiiarkcil dcprt'SMioiiH, III voiiiij^ .siu'i;iiiioiis, till! arms arc fri'c almvi' tin- siroiid distirliiil, ami tlii'io an* liiit fivi' |i:iirs of arm o|iL<iiiii^s. wliiili arc arriuigi'd as llic ten in llu' oldiT ont's, lU'twi'i'ii llii'so two forms tliori.' aru otiii'i's of intrrmcdiali' ftaj^i's ill which, aUlii)iiL''h haviiij^ ns yot hiil ti'ii o|u'nin;:s, iIr'sl- are arraii^'-ril siiijflv — not ill pairs — and their axillary di-iidials form tlio iippirmost plati; of till' ray in tlu' oalyv. Arms loii^'. riillit'i' stout, firipii'iilly dicliol- omi/in^. Iiiterhrai'liials in lar^.^' spocimi-iis : I, 'J, 2, !), 4, 4, 2, witli xlight varialions in the upper rows; iiiterdisiiehals. 1, 2. •'!, 2; iiiial iiiterradins : 1, .'J, I, o, 7, and 11 mimlier of smaller plates aliove. 'I'lie smallest speeinien under I'xnmination has Imt 1. 2, 2 interhrachials. a sinule very miniili' inter- distiehal. and ■'■, I, and '> plates ahove the (list anal. Tej;men low hemi- spherical to almost llat, with distinct plications towanl the outer m.iiyin — corresponding to the rnys and their main divisions — and a slight groo\e at ilic anal side. I'osterior or.'il higlily coii\ex. conical, or even .spinous, and Hometimo.s n.s jnrgo as the fimr olhers together, from which it is separated hy ■several rather large, tumid plates, and in the linger spicimens liy very small, irregular, Hat pieces of suhseipieiit growth interspersed helweeii the larger ones. The smaller orals and radial dome plates are surrounded hy dimilar plates, which increase in nuniher, as well as in size and convexity, with the size of the specimen. In the smallest exami)]es liefore us (here are five minute, isolated pieces, interposeil at the ends of the inter-oral .sutures, and the orals arc Htill in contact among themselves and with the radial dome plates hy small surfaces in the next largest specimens, the interposed plates, allhongli yet very small and llat. ari' nnited laterally so as to separate the orals, as well as the r.'idial dome |ilatcs, In the largest specimens, the interposed plates are not only larger hnt also convex, and hundreils of secondary di.-k plates are introdiiceil hetweeii them over the whole surface, reseiiihling in form and chariicter the jjiimary ones in their earlier phases. .'>uch ])iece.s are foniul also in vast numhers near the outer margin, decreasing in size as they n]iproacli the arm openings. The radial dome ])lates — /. c. rovering jiiocos — are very irregularly developed, some rays having hut a single plate, others four or five, and while some of them are isolated, others are in con-

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llAKKIUNID.i:.

u35

fnrf iiiid iilfiTmitd willi oiio iiiuillaT. Aniix iit iIil' cikI <if a |ii'olKmciilifui'tu (ii'otiilii'raiii'c, williiii tlio arm ic^itiiis ur u link- aliovu oi luluw. '. /'..nm larj^i- iiiil long. In u laigf Hpcciuaii it was loiiiiil inesiiM.'il t' i I iii.' 'i (if til I'l- I'l'ot, liiil cviileiitly wan connitli'iiil*!}' longer; it giai'nulU sin rinKid ilH ilianii'tor Iroiii 1 1 iiiiii. at tliu tup to 'J I nun. at iliu (li><lal ti\'l. Niui' the calyx, llic ikmImI jointM, wliicli at tlicir uilgcs arc ronmli'il ami Minieulmt iiii- tinlating, inoji'ct cuii'jiicuon^ly over llii- yonngc.it ainl llitii-i' of intiTinciliatu growth, lint JiirtlitM' ilovvii uii tliu xtvin t''<, latter attain tliu m.v of ilic uldct, ami a wiilcr jciiiit always altc'rimli).'4 witii ii narrower one. 'I'oward tliu di.x- tal end all llif Joints ln'coine of tin- saiiic l<'n;:lli an<l widili. tin ir |iro.\iiiial and ilistMl Miirl'iKci iirc iiivcn-d with line rndinlin^^ r<triii'. and tlu' lini'K of union art! /.i;.;/.ajr. ('cntial ciiiial I'.xlri'nii'ly large, ocTn|iying one third the ilianieter ol' the Joint, and oliMcnr(dy |u'nlalohate. The lower end ol' the coliiinn ha« mil hi'eii oliseived, hnt IVoin detarhed |iartx. whirii nndoiilitedly lielong to thin 'iieeiiw, it appears tiiat it was pro\idi'd I'or (|iiite a di-lnnce with long nntl .stout hrandies, which wi're perlorated hy a canal of elmi- gate fonn.

Ji'iT.'iii iiiiil F.'iriililii. — Found in hoth divisions of the niiiliiiL'ton group >ip to the while crystalline layer.s ot' the npjier iied ; lUn lington, Iowa, and Henderson Co.. Ills.

Hi iiiiiil,:*. — The -i/.e of this species is exlreinely variidile. Among the fiflytwo specimens under examination, the calyx varies iVom ft to (iri mm. in length, ami from 7 to S.") mm. in width. As a rule, the specimens from the I'pper Hmlington division are a .shade larger, yet AVhite's type uf Jt/ii/in("i'iiiiii!< jil'iiKi, the rpper hed iorni, in the .Mnsemn of Comparativu Zoiilogy, is considerahly smaller than the largest specimens IVom the Tower hed. .V. jil'itiix was said to dilVer '• hy its convex hase. p .'niin .t ia>al |ilates, clr inided sutures, and the proportions of the hody plates ; " hnt iieiihi'r one of these distinelions will stand when n lurge nnmlier ul' speci- mens are c<iinp;ired. The hasals are not prominent in any of ihcin — not even in the type — and the snliire lines are not more chaniuded than they are in specimens from the T.ower hed. Ar/imirriiiiis miimr, A. aiijiii-Jnlti.i. and A. fii-i '■ii'iiniis, which m'c ha\'e always held to he one species, rc|)resent earlier stages in the (K'veloinnent of Mriilxliii-riiiiiy h'niiisi. as we suggested in the Itevision (Part II., p. I'JS). " Aclitidrriniis " )in)iiir with t"ewer anal plates, and the anal npertiu'e much lower on the posterior side, rcpresenis the youngest foi'in of the species, and .1. Knjicr/nlns and A. hrcrlrDnii.i a transition hetwdi

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536

THE CUINOIUEA CAMEUATA 01' NORTH AMERICA.

tlie young and the adult. The two latter are said to differ in the iniiuber of interbrachials, in their surface markings, and the condition of the posterior oral, whether spinous or not, — characters unreliable for specific separation. Mi'ffistocriiiiis jMirvirostfis M. and W., which is comparatively small, and of which the anus is described as located below the arm bases, is the younger stage of " Mc(jislocnmts ijlcnus," both coming from the Upper bud. The position of the anus in this species is quite variable, being sometimes be- low the arm regions not only in the smaller specimens, but frequently also in the larger ones.

This species is interesting for the light it throws upon the growth of the individual. In the smallest, and, as we think, youngest specimens, there are but two arm openings, the brachials being free above the second distichals, and remaining to a large extent in the condition of arm plates. The larger and more mature specimens, with the interbrachials increased to more than twice their previous number, have four arm openings, and the hlsirial distichals and palmars, the latter as far as to the fifth row, form part of the calyx walls. The tegnion in its earlier form is composed of but few plates, and the orals are in contact among themselves and with the radial dome pieces. Gradually with growth small supplcmentar}' pieces were intro- duced, and between these, which increased in size, were interposed in turn hundred.s, and even thousands, of minute secondary pieces, still more increas- ing tlie capacity of the calyx, and encroaching upon the ambulacra so as to leave but a few isolated ambulacral plates exposed at the surface.

Megistocrinus Evansi var. crassus OVuite).

1862. White ; Proceed. Cost. Soc. Nat. Hist., Vol. IX., p. 17. 1831. W. and Sr. ; Kcvisiou PBloeocr., Part II., p. 137.

Calyx very large, differing from M. Evansi in the massiveness of its plates and the greater depression of the base. The radials are formed into high, broad knobs with deep channels along the interradial and basi-radial sutures, and their surfaces are covered with coarse irregular corrugations. The nodes of the brachials and interbrachials are more conical.

Horizon ami Locality. — Lower Burlington limestone ; Burlington, Iowa.

Type in the Museum of Comparative Zoology.

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BATOCRIMP.E. 537

Megistocrinus nobilis av. and Sr. Plate XLVlI.Fujs. G, 7, 8u, b, and Piute LI. Fly. 8.

ISOn. W. niul Sr.; Geol. licp. Illinois, VcjI. VIII., p. lf,9, riulu 10, Figs. 6 mid 7. IS'JO. S. A. XIii.i.i:r; Xorlli Aincr. Guol. mid I'idii'oul., p. 2(10.

Sjii. Miyislocriims purciis W. mid Si', j Gcol. Kup. Illiiiuis, Vol. VIII., p. 171.

Somewhat .imaller than the jiroceding species. Cal^x subgloliose, nciuly as wide as liigli ; the tcgnien (lei)ie.sseil honiisphcrical. Doixil cup to the Jiiifhlle of the radiala sliglitly Ihitteiied, but still convex; the co.stals and proximal distichals gently curving ; the higher brachials bending outward and curved transvcr.sely, forming ten lobes around the calyx, correspond- ing to the main divisions of the rays. Plates heavy, a little concave ; suture lines somewhat grooved, tho.se between the basals and radials deeper than the others.

Basals small, forming <a hexagon, of which only a narrow rim is visible beyond the column. Radials hexangular in outline, a little wider than long, the upper and low3r lateral faces of equal length. First costals as large as the radials ; the two posterior ones pentangular, the other.s hexangular. Second costals smaller than the first, and pentangular. First distichals as large us the axillary costal ; those of the second row .«omewhat smaller ; suc- ceeding distichals biserial, the plates alternating, and decreasing rapidly in length upward. There are four plates iu one series and five in the other, both followed by two series of short transverse palmars, which to the third plate take part in the calyx, and bifurcate again above the fifth or sixth. Arm facets arranged in ten pairs, large, and directed upwards. Arms short in proportion to the size of the cal3'x, bifurcating three or four times, the tips infolding ; they are robust at their bases, but diminish in size with each bifurcation, and are composed of moderately short pieces. Pinnules short and rarely preserved. Regidar interbracliials in five or six ranges: 1, 2, 2. 3, 3, 2, with .slight variations. Interdistichals' in three or four rows ; the first generally resting upon the second distichals, rarely upon the first. The first anal plate longer than the radials ; the three plates above as large as the first intorbrachial of the other sides ; followed by four or five plates, and these by numerous others of indefinite arrangement. Ventral disk from almost flat to moderately convex ; the plates flat, of almost uniform size and irregular nrrangemcnt. The orals, if represented at all, indeterminable,

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TIIK CRINOIDKA CAMERATA OK NOUI'II AMKHICA.

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as also tlio aiiiljulacrnl [ilatos, oxci'pt near tlio outer margins ot' ilio tegnien, where well delined covering and nide pieces are on a level with the inlerani- bulacnils J and similar pieces ocoiu" along the arms, T!ie covering plates are quite regular in their arrangemOnt, forming a sort of ridge with a row of side pieces at each side. Anus cxcentric, at the top of a short, rounded or conical protuberance. CoUnnn large, giving oil' heavy brnnehe.s nt the distal end ; it increases but little in width, and i.s composed throughout of alter- nate thick and thin joints:. Central canal moderately large, ob.scurcly penta- lobato, and proportionally wider at the lower end.

Iloraun and Lovalltij . — Kinderhook group ; Le Grand, Marshall Co., Iowa.

Tijpe at Pasadena, California, but authentic .ipeciincns are in the collection of Wachsnnith and Springer.

Jicnitirk.s. — Jfiylstocriiius /larrm^ has the samo nfiinities with 3f. )inhi/is as '• AcliiKicriiiHs" hrcricurnis with ilirji.itorriniiti Ermis'i, and we regard it a 3-oung .stage of that species. The arms are free above the disticlial.s, and it has less interbrachial jdates. The specimen, Plate LI., Fig. 8, is some- what abnormal, having but one costal in two of its rays.

Megistocrinus latus (TrAi.i.). riute XL Vlll. Fifje. 3a, h.

1S58. Hai.i.; fie .!. Kqi. \m\n, Viil. I , I'ait TL, p. ■t'^O, Phite 1, Figs. l,r, b.

ISSl. \V. im.l Si'.; Ui'visioii I'liln'ooi-., I'iirt 11., p. Vi%. '

A large species. Dorsiil cup short, about twice as wide as high, abruptly depressed at the bottom ; the sides expanding upwards; arm bases slightly projecting; plates Hat and without ornamentation; sutiu'e lines grooved.

Hasals closely anciijloscd, rather large, located at the bottom of an inverted cup, which is a little wider than the column. Kadials about as wide as long; their lower ends abruptly curved to form the sides of the basal concavity, the other portions spreading horizontally and constituting tin; liottoni of the calyx. First costals generally longer than the second. Distichals in the antero-lateral rays three, supporting two arms; the other rays have a single axillary, followed by several palmars with four arms to the ray. Interbrachials; 1, 2, .", .", and some small pieces between the arm bases. The first anal plate, which is a little narrower than the radials. is suc- ceeded by three plate.s, and these by numerous irregularly arranged pieces,

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wliich docrenso in size iipwiird.s. Intenli.sticlmlH ono or two, placed longitudi- naiiy. Ventral disit lieiuispherical ; the plates nearly (hit and of irregular arrangement ; orals and radial dome ))late.s a little larger and convex. Anus Hubeenlral. Column strong, the uxial canal large and obtusely pen- tangular.

Ilurizon and Locality. — Hamilton group, New I'.ull'alo, Iowa.

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Megistocrinus Farnsworthi (Wmn:). riuk XL VIIL Fii/H. 4rt, h.

1870. AViriTE ; I'mcml. Ao.-id. Niil. Sci. Tliilii., p. 29. 1S81. W. mill Si'.; Ruvisiou I'lihuior, l\n 11., p. i;iS.

Of moderate size. Calyx subglobose, nearly as high as wide ; the lower portions of the dor.-^al cup to the middle of the first costals truncated, the sides almost at right angles with the base, very slightly expanding to the arm bases, the latter somewhat projectiiig; the plates convex and without ornamentation.

Basal disk proportionally large, slightly projecting; the central part a little e.\cavated for the reception of the column ; axial canal rather large and obtusely pentangular. Radials horizontal, smaller than the costals. First costals abruptly curved ; the lower end of the plates on a level with the radials, the upper ends vertical. Distichals three in the two antero-lateral rays; in the three other rays but one, which being axillary is succeeded by 2X4 palmars. Arms sixteen, arranged in groups of two and four; the arm bases a little projecting. Interbrachials: ], 2, 2, 3, followed by several smaller pieces between the arm bases. The first anal plate, which is a little narrower than the radials, succeeded by rows of three, four, and six pieces, with numerous irregularly arranged plates above. Interdistichals two to four, the lower one sometimes touching the costal axillary. Ventral disk high, slightly conical; composed of rather large pieces. Orals completely isolated by supplementary pieces ; they are larger than the surrounding plates, but not more prominent. Anus subcentral.

Ilorizoii ami Local!///. — Hamilton group; Solon. Towa.

Ti/pes in the Museum of the State University at Iowa City.

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THE CKIXOIDEA CAMERATA OF NORTH AMERICA.

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Megistocrinus depressus (Hall). Pia/e XLIX. Figs. J, ,',, and 4a-d.

1S03. Ham.; Ijlli l(.|i, N. Y. Slate f'ali. Nat. lli^l., p. llii. 18S1. W. lui.l Sr. ; lii'vUicin I'aliiviiT., I'ai-I II., p. VM.

Syii. M,yi.y/Mvi,iiiH uiitnrio ll.VLL, Ibdil Ijlli \W\i. N. Y. Slnle Ciib., p. ISfi.

A.s large as tlie preceding s|)eclei<. Calyx ilepressed, wider tliaii high ; the dorsal cup basin-shaped ; the bottom part to the middle of the first cos- tnls — sometimes higher — flattened but not excavated; the sides slightly expanding to the top of the distichals, thence curving outward and forming a short rim. from which the free arms are given olT in jjair.s. Plates flat or a little concave, thickened around their outer margins, and in well preserved specimens covered by numerous very fine, somewiiat irregular striiv, which are more pronounced near the suture lines; the middle of the plates .sometimes sliglitly elevated, and the surface covered with small ir''egnlar pustules.

Basals small, only the points of the outer angles visible beyond the column; almost flat, and on a level with the radials; the axial canal large and indistinctly pentagonal. Distichals from one to three in the calyx. Three of tlie rays have a single distichal in both divisions, which is axillary and followed by 2x2 sliort palmars, the other rays two additional distichals and no palmars. Ann openings sixteen, arranged in eight pairs. The median lines of the higher brachials arc ornamented with indistinct, longitudinal riilges, covered by similar stria) as the other parts of the plates. Inter- bracliials : 1, 2, 3, with two or three irregular rows above, which meet the interambulacral plates. First anal plate, which is a little larger than the radials. followed by o, 4, and 4 pieces, and these by a number of smaller ones. Interdistichals one to three, arranged longitudinsilly ; the ra^s with four arms generally having three, the other.s not more than two. Ventral disk depre.sscd-conve.x ; the food grooves marked by ridges, which diverge to the arm bases; the surface is covered by rather large, flat, irregular pieces enclosing the orals and radial dome plates, which are but little larger than the rest of the plates. Posterior oral in contact with the other.*!, central and spiniferous, while the other four are generally flat. Anus excontric.

Ilirlvon and Localitj- — Hamilton group ; Western New York and Louisville, Ky.

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Jiiiwtrh. — We liad for coiiipari.xon ii luimbor of specinu'iis from llu' Ainei'iciin Museum at New York, xoiuo of wliicli Prof. Hull Inul liibclcd M. tJijmx.siis, otlioi'H J/, uiitiirio. Tlienu .specimuus, iu our o[)iuiou, diner only in the greater or less depression of the calyx from outside pressure, and in the greater convexity of their secondary radial dome plates, whicli in some specimens are strongly tuberculous, in others almost perfectly Hat.

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Hegistoorinus nodosus (HMtius). Plate XUX. ri<js. o,t, h.

187s. ItMiiiisj rnici'cil. \h\u-\\\\ XnA. Niil. Sci., Veil. 11., y. l."-5, I'liilc 11, Fig. t. ISV), lUiiiiis; ilii,!., Vul. IV.. |i. ',)'.), I'jiilr 1, I'ii;, 8 and I'liile ;!, Kiy. i. Issl. AV. mill Si'.; Hfvisiou I'lilinic-r., I'lii-t 11., \\ lliS.

A largo species. Dorsal cup broadly urn-shnped, the truncated part embracing basals, radials, and first anal jdate, which are in about the same plane ; the sides of the cup, whicli rise from the lower enil of the first costals, slightly convex, expanding near the arm bases. Plates without ornamenta- tion ; but the costals and the intorbraehials of the two proximal rows are .somewhat nodoso, while the radials are slightly convex, and the distichals anil upper interbrachials almost flat.

Basal disk but very little projecting beyond the colunni. the column facet excavated and surrounded by a well defined cireidar rim. Kadials and costals increasing in width upwards ; the radials longer than wide ; the costals wider than long. The higher orders of brachials arranged as in the preceding species. Arms sixteen from the calyx; long, slender, bifurcating, and composed of a double scries of interlocking pieces. First interbrachial as large as the first costals; followed by three or four rows of two plates each. First anal plate succeeded by 3. 4, 4, and 3 plates. Interdi.s- tichals two to tiiroe. Tegtueii highly convex, .somewhat iiifiated ))Osteriorly, the interradial and interaxillary spaces deeply grooved from half way down to the arm regions ; the posterior groove broadest and deepest; the sinface paved by ninnerous irregular pieces, among which the orals are larger, subspinous, and not in contact; the radial dome plates strongly nodose. Anus subcentral. Column large.

Horizon and Locallfy. — Hamilton group ; Davenport, Iowa, and Alpena, Mich.

TiJiKS in the Museum of the Davenport Academy of Natural Sciences.

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542 TlIK CRINOIDKA CAMKRATA OF XOIMII AMKItlC'A.

HegistoorinuB multidoooratua (IVummh). rUdc XLIX. Fuj. 0.

1S83. .\fi</ji!itoeniiiiii Hodoaiii, vnr. luii/lii/fi-oni/iia — IIauuisj I'rocccJ. Dnvciip. Aciid. Nut. Sri., V(j1. 1\'.

11. 100, I'liite 11., KiK's. .'I iiiid h 1SS5. W. null Sp. ; llevisiiiu riiliuucr., I'lirt 111., |). 113.

Tliirt specicH ngrees in the general form nnd tlio nrrnngemont of llio plates elo.sely with Jf. iwdo'fKs, hut did'ers essentially in the extent and ehar- actcr of iti ornamentation. Tiie plates, instead of liaving a single central node, are covered hy series of nodes, and these are not restricted to a few l)Iates as in that species, hut cover every plate of the calyx. The nodes arc as a rule well defined, hut of irregular size and without definite arrangement, and they vary in number in different plates ; the radials, costals, and first interbrachials liave from five to twelve, which are arranged in rows; while the higher brachials seldom have more than two or three at the most. Tlie ])lates of the tegmen are also highly ornamented, each one bearing a central node, from which rows of smaller nodes radiate to the angles. It may be fiu'ther stated that in this species the dorsal cup is less flattened at the hot- toni. the railials are proportionally larger, and the first costals take part in the lateral walls, and not in the truncated lower portions. Number of arms, position of anus, and form and arrangement of orals and radial dome plates as in the preceding species.

Jlorh'iti mill Lorali///. — Hamilton group ; Alpena, Mich.

T'/i^-i in the Davenport Academ}' of Natural Sciences.

lii'iiiarlctt. — We regard this form as a good species, and not a variety of J/, noilosus as supposed by Barris ; the diflerences are very marked and con- stant. We examined a large number of specimens of both forms, and experienced no dilliculty in distinguishing them promptly.

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Megistocrinus rugosus T.vox mul Cvs.*. Plate XL VIII. F;>/s. Get, h, c.

1859. Lyon mul C.tss. ; Amcr. Jourii. Si'i., Vdl. XXVIII., p. 243. 1S81. W. nml Sr. ; Ucvisicm Palimcr., I'nrt 11., p. 13S.

Calyx depressed, its height to the base of the anal tube one third less than its width. Dor.sal cup shallow basin-shaped, yet considerably higher than the tegmen, three times as wide as high, truncated to the middle of

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the first costalH arid first iiitorbnicliiiils, tliuii curving nliriijitly ninvanl, widen- ing « litllu in tlic upper imrt, Surl'iiee of plates, e\('('i)t Imsals iinil radiiils, strongly nodose, the nodes cut up hy irregidar grooxes or coarse wrinkles, which give to the Hpeeies an extremely rugged apiiearaui'e,

BiisuU sniall, (lat, disk-lilie, slightly depressed, only the points of the nnglcH projecting licyond the column; central perforation large and pcntalo- hate. Radials, first costals, and (ir-^t anal jdate hexagonal and of nearly the same size ; the second costals pentagonid, hexagonal, or heptagonal, owing to the height of the interhrachials of the second row. Distiehals itX 'J in the antcro-lateral rays, decreasing in size ; the lower one almost as largo as the preceding axiilar}'. The three other ra^s have but one distichal. and 2 or 3 X ■! fixed pahnars, of whicli the uppir one is short ami curved like an arm plate. Arm openings sixteen, arranged in groups of two and four ; the arm structure not known. Interbnudiials: 1. 2, ;>, .", i). Anal plate followed l>y rows of t, 5, and 4 plates, and a few irregular pieces at the arm regions. Ventral disk depresscd-suhconical ; comjmsed of numerous convex pieces ; the orals and radial dome plates largo and spinous, and all isolated. Anal tube excontric, strong at the base; consisting of slightly elevated j)ieces with spine-bearing larger ones interspersed. Colunni unknown.

/I'irh'iii ami Livalili/. — Hamilton group (Corniforous), Clark Co., Ind., and Louisville, Ky.

Megistocrinus concavus Wai msmi th. Plate XL VIII. Fhjs. Sa, h, c.

I'!'*,). AV.vf MsMCTit i I'lni ,1. Duvciip. .\cii(l. Niil. Sci., Vol. IV , p. 90, riiitc 1, Figs. B, C, 7.

1SS3. W. 1111(1 Si'.; lluvisiim I'lilii'iin-., I'iut 111.. |i. 112.

A rather aberrant form of the gonus. Cal^'x wider than high, the ventral disk higher than the dorsal cup; the latter very shallow, abruptly depressed to the top of the radials ; the first costals spreading horizoiitallj-, and form- ing a wide and deep -Mverted cup; the second bending abruptly upward so as to place the upper }.n i of the calyx almost at right angles to the trun- cated lower part. Plates heavy, and except the l)a-^als, radials and first onal plate, which are (lat or a little concave, produced into broad, very prominent knobs.

Bas.ils of medium size, forming a hexagonal disk, which occupies the bottom of the concavity. Radials comparatively small, slightly bending upwards, and constituting together with the lower margins of the first costals

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llio >i(k'-' of till' invi'ili'il cup. Co^tnls liir^'f, llieir kiioliM vuiy |ii'iiiiiiiu<nl, unil urmngod with lliosu of llie firnt intfibracliiuls into a circle, wliicli mh roiimlrt tlie concavity. Di.sticluils rather large, consisting in the nnlero latiTii! ray M of two or three platen, which form the hase.s of two primary arms; the thrue other rays Inive u single plate, which is axillary ami supports two pal- mars from each side ami two arms, thus making sixteen piiimiry arms to the s[)ecies. Till' arms are not preserved in the specimens, Imt. (o jndge from the si/.e of their facets, weie inooerately stout. Interhrachinls disposed in rows of one, two, niiil three pieco.'*, so arranged us to i'min, together with the lirst and second costals, respectively, two will delined ciiclets of plates aromid the radials. Anal interrailius consideralily wider, and niaile np of a greater iimnher and smaller plates. A'entral di.sk iiighly elevated, siih- conical ; the orals and radial ilomc plati's larger than the snrromiding plates, and extended into short spines ; the smrounding plutoH tidicrcidons. Anns almost central. Colunui of medium size ; the nxial canal wide nnd obtnscly pentangnlar.

Jforivoii (iml Lnriillti/. — Hamilton gronp; Alpeiin, Mich.

Ti/jirs m the Mnsenm of the Davenport Academy, and in the collection of Wach.siniith and Springer.

Megistocrinus spinosulus T.vnv. ^lHU^ XL VI f I. F;<js. J,u I>, r, ami J.

IHfil. I.vnx ; VtwivA. Aciul. Nat. Sci. riiilii., p. 4i:i, I'liitc 4, I'igs. "», b. 1S51. W. mill Si'. ; Ui'visicin riil.i'ncr.. I'lirl 1! , p. 1:IS.

Svn .)f'yis>m;-iu«i ////«(/«» — S. A. .Mll.LHl, l'>?!»; Cinoiii. Scic Nat. Ilisl,, Vol. II., p. HI, IMiilc 10, l''ij,'s. 1(1, 6.

Of the type of JA rtnjosiis, but having eight nrin openings to the rny, which arc arranged in n continuous row aroiuid the calyx, and not in groups; the basals .slightly projecting instead of concave, the radials more depres.sed, and the anal tube more excentric. Calyx short in proportion to its width, which at the arm bases is almost twice its height; truncated to the middle of the second costals. The latter plates, and the interbrachials of the second row, are extended into very conspicuous tubercles, and somewhat shorter tubercles mark the first distichals and the interbrachials of the third row; all other ])lates above and below nre slightly convex, except the radials, wliich are a little concave. The sides of the dorsal cup stand almct't at right angles to the base, expanding slightly to the arm base.s. Ventral disk low, a little convex, somewhat bulging at the posterior side.

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G45

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DiiMiils very Niniill, flij^'litly inojfctinj,^ liitiTully. iiiid noti'lii'd nt tlio Miiturt'x, the coliiinii liicL't tk'[trL's,>(t'(l ami HUiioiiink'd liy ii circular cIi'viiIimI rim. Kmliiils ycncnilly wider timii tliu fust uind idiitc, roiiiiiny ii sludiow di'iircs- ciou; the ciiiyx rer<tinj{ upon tlio lir.tt costals and (ir«t iiiterriidiiilf*. ('o.slnlM larger tlian the radials, aijoiit an wide as limj;. Disiiclml.s axillary, nn largo as, or larger than, the second costals ; followed by a row of axillary jialinars, and these liy ii row of post-palniars, which are directed outward, and suppoit eight primary arms to the ray, forming an imintcrrupted line ainund the calyx. Interhraehials ; 1, 2, 2, 2, 1, 1, tiie two upper very small. The plates of the first row, together with the (Irst eosials, foi'ming a circlet, around which another circlet is formed hy the second row of interradials and second costal.s. Anal intcrradius wider; the first nnal supports throe plates, which are a little narrower tlian the single plate at the other sides, and there are ■1. T), ;i, 2 and 2 pieces above. Iiiterdistichals two, arranged longitudinally Togmon composed of a great nuniher of irregular pieces. Orals not in con- tact, somewhat larger than surrounding plates, but not otherwise distin- guished ; placed between the centre and margin of the tegnien. Anus more excentric than in any other Devonian ^fl^glsf()^^rinl(s, with the possible excep- tion of J/. (ilmofni'iK. Column unknown.

Horizon (Old Lovallli/. — Ilnniilton group; Louisville, Ky., and Colum- bus, O.

Tl>/j)(;n in the Lyon collection at Jeffersonville, Ind.

liiiiKirliH. — This species differs from all others of this iieiius in having eight primary arms, and in not having them distributed in groups. It has the third bifurcation in the calyx, which in other species takes place in the free arm.s.

Miller's Mcgintocrhuis jjileatiis from Columbus, 0., we take to bo identical with this species. That his specimen has but .six and seven arm openings in the posterior rays, while others liave eight, proves nothing to the contrary ; the specimen very probably was not quite mature, and represents a transi- tion between our still 3-ounger spoeimeii from the same locality with only five and six arm openings to the ray (Plate XLVIII., Fig. 2). and the larger Louisville specimen (Plato XLVIIL, Figs, la, h, c) with eight primary arms all around.

69

il

II

k •■

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I

i

o40

lin. (UINOIDK.V lAMKUATA ol' NnUIIl AMKlllCA.

il

1

w

('*) MoglBtoorinuR abnormii (I.yhn). I'/al, A7-/.V. /•'(//>. /", Ij,':

.{.-HniH-fiilHt „U,rm,» - l,\ns ; (icul. I(,|). Ky, Viil. Ill,, p. 1711, Pllllr t, Fiffi 1, 1«, *.

M-yii/<iivi,iii' iiliHin'iiKi — Mil M till! ; (iiiiil. I'iilii"^. Ku'<», N. Anil r , p. IIMi. Mtiii^hti-ritiH^ iihtittt'iitin^ W. and Si',; Ui'vi-*!!!}! I'alifucr., I'url 11., p. l.'t/,

TliiM HpecieH !« ri'iniiikaltli' for tliu Ini>^c lohes iit tlie iinii logionw, wliich i;ivi' to till' nihx II (li^tiiiftlv iicntiilnliate (iiitliiio, with dci'ii iiiti'iTiilial iiotclii'."*. Ddi'Miil I'lip miiiu'i'I'-nIimikmI, II litilo lliittiMii'il at the lioltoiii ; the liliitfM thin, llitt or nli^htly concave, and duvoid of ornuini'Mtatioii.

liiiMid^ ill the saiiK! |iImik> with thu radial^, foniiiii}^ n Hat licxaijonal dir<k, ol' which only a niiiinw iiiargiii is vi.-ihlc 1)i';ti)iid tlie coliiiiiii ; cciilnil caiinl liir),'o and oi)t lively iicntanj^uliir. Ifadiiils and costals nciiilv of i'i|iiid ni/.o. Di.Mtichidj* 3X2 in tho two antoro-hitcial rayx, Hupportinj,' the anim; the tiirct' other nivs have an axilhiry in each divinioii ami 2 X | paliii.'irs. Prim- ary iirm.s sixteen; iirranjfed : 1,1. Inferlii'achia],^ ; 1, 2, .'1. 11. .'! ; the fii'Mt, ns liiri,'e as tho riKlials; those of the second row about the sniiii' si/e as the dislichiils; tho plates of the tliiril row consideriiiily sinidler ; the middle pieces of ilie I'oiirlh row ol'teii lociiled in the te;;nicn. Interdislichiils one or two; there are i,'eneially two in rays with four arms, and the lower one rests upon the triiiiciiled middle part of the prccedin<; axillary, Init where there is hut one it occupies the notch hitwcen the (irst disliehids. Anal intcirniliiis extremely wide and somewhat lliittened ; the (irst anal, which is fully as liirjfe as the radials, often supports four plates in the first row, nnd five to seven in the second nnd third. Tejfmen lii^ddy convex, com])osod of meilium sized, irrejfular, Hal pieces, tho amhulacra niaiked iiy ridges, and tho interambulacral spaces hy depressions. Oiids in rontnct ; the posterior one and the radial dome plates strongly tuhcrculoiis or suhspinous, forming six conspicuous promiiiencivs upon the surface. Anus located a little ahovc the arm bases, opening out through the flat surface of the teginen.

Jfon'voH mill f.iini/i/i/. — Corniferous ; Louisville. Ky., Clarke Co., Ind., nnd Marian Co., Ky. Very abundant in some localities, but good .specimens quite rare.

T,'/jii!i in tlie Lyon collection.

Jlfimirh. — This is not a tv]iical il/iy/.'s/i^rr/yn/'j. nnd wo have referred it with much hesitation to that genus. It departs from the typical form in the wide nnd deep depressions at the arm regions, in the flattening of the nnnl

7

i

'/

HATOC'UINID.i;.

547

»

iircii, 1111(1 in tlio furiii iiiid pi).-<itiuii ol' ihu uimim, in nil nf wliidi ii a'Nfiiiljlt.o Aiii'iicr'miis. l.yoWn t_) pc ii in nil iilinornml condition, and we liiivi- (Igiiii'd otiier HjiocinionH in plui'c of it. It Iiiim Imt lour iiiiii-ljouiing iii^h, the jionIcio- liitui'iil my ii|i[mrt!nll_y' having lu'cii injiirt'd diirinj,' liii- lilV of llic Ciinoid, and tlio N|ia('i) IVoin tliu lirnl axillaiy ii|i lioing liili'il liy aluioi'iiiid growth. Ik'Midt's tho loft antcrodatoral ray lian four in jilacc ol' iwo piiuiary artnii. Whuliiur tho arms of tliiM npfcioM aru branciiing \n noi luiown.

OENNiBOCRINnS W. miM .s,.,

issl. W. mill Sr.; rtc'vi»i.iu I'lilimn-., I'liil 11., |i Hill (I'n.ircl, Ai'iiil, Nut. ^i i, I'Mlu , p. :);)()■

h',)l. ^. A. Mii.r.t.ii; NiJi'ili A I'. (m'uI. uihI rulinnil , |>. HI.

Myu. .{•■liiiiwriiiuf (ill |iiirl).

Calyx distinctly lobed ; the inti'rradial Kpaocs extremely wide, and deeply indented at tliu arm regions. lMate.s tiiin, their surface.s ornainiulfd uiih railiating Htriie. Ua,«als three, snudl ; the axiid raual huge and peiitidohale, Hadiais and eostals ol" siiuilar form. Init dtcn ii.«ing in ."ize upwards; tlio iirst costal hexagonal, the second heptagonal. The liraueliing of the rays al)Ove tiie distiehals is front alternate sides, the seconil plate of the two main divi- sions giving off at one side an ari", at the oilier hi'achials of n higher order. the last axillary supporting two arms, Tin.' dKlereut rays have the same niimher of arms, which is eight, ho far as ohserved. lulerlirachials (piite numerous, and the upper ones in contact with the interaudjulacrnls; tlu' lirsl is followed hy two or throe in the second row — which are larger ihiin usual in the IJatocrinidic — anil those hy three or four .smaller ones. The (irst anal plate supports a second, which has an interhrachial at each side, and there are several rows of four or more plates above. The tegmen is com- po.>ic'd of rather small plates, and ri,<io« but little above the dor.sal cup; the surface is iindidated, being grooved and indenteil interradially. and distinctly raised all along tho food grooves, which arc covered by two rows of alternate pieces. Orals proporli'mally small, the posterior one a little the largest. There is no anal tube, tho anus being represented by a small, excciitric opening, passing out directly through tho tegmen.

Dintrihiition. — Restricted to tho Hamilton group of America,

T//j)c of the genus. — Gciiixrorrlniis li'i'iiti(rl:ifii><!)f (Shumard).

licmarJis. — This genus, in tho branching of the rays, grouping of tho nrms, form of the tegmen, and in the simplicity and position of the anus.

I'

548

THE CRIXOIDEA CA.MKRAl'A OF NORTH AMERICA.

closely resembles I'h^sctucriniis, but that, having no anal plute in the first iutorbracliial row, is an Actinocrinoid.

P I

:; Pi

1

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Oennssocrinus kentuckiensis (Shumakd). riato XXXIV. Fi<j>i. 11, U, 13.

ISflfl. ActimcrUus hiitiickivdsis—'inv&w.n; Trans. Acnil. Sci. St. Louis, Vol. II., ]i. 315. 18S1. Geimieoeriiim Ini/iir/ani.'is — \\ . and Si'. ; HciiM.iii riilitucr., I'art II., p. 101.

Svii. Ai'liiKii'riiiKs rnfiihirfun ],V()X 1111(1 C'A!>stu.vv, ISo'J ('lot Uall, 1S5S); Aiiier. Joiini. Sci. (11. serifs), Vol. XXVUl., |i. iliS.

Svii. J,ii,i<j,ri,iii-i iij/<.<ii U.vi.i., IbUi; lOlli Ui'l'. X. Y. Sliilc Cab. Albany, ]\. ]i».

Of inodium size. Cal\-x wider tiian liiyli, decidedly lobed at the arm regions, and the arms given oil" in clusters. Dorsal cup semiglobose ; the surface covered with well-defined stria) proceeding from the centre of the plates to their margins. There is a ridge to each face of the plates, and another to each angle, which meet with similar ridges from adjoining plates, and form with them all sorts of triangles. The ridges following the rays increase in prominence as they approiich the distiehal.'<, and attain at the arm bases almost tlie width of the arms.

Basa]-" very short, .slightl^v projecting laterally, forming a thin trilobate rim, which is flat at the bottom. Kadials and eostids as long as wide, de- creasing rapidly in size upward ; the second costals less than half the size of the radials. Disticlials 2 X 10, comparatively small, wider than long; the second ones axillary, supporting 2X4 palmars, of which the two of the outer sides are followed by one arm, the two iinieronos by two arms, the first plate taking part in the caly.x. There are eight arms to each ray, in close contact ; while those of different rays are far apart. Wlnther there is any brandling in the free arms is not known. Interbrachials: 1, 2, 4 (some- times 1, 3, 4); succeeded by one or two rows of smaller pieces, of which the npper interlock with the interambulacral plates. The lirst anal piece sup- ports three large plates in the first row, five in the second, and five or more in the third. Interdistichals three in two rows. Ventral disk depressed- convex ; the interambulacral plates together with the interbrachials form wide and deep recesses around the calyx, while the radial portions project conspicuously upward and outward. All plates of the tegmen of nearly uni- form size, and each one covered with a small central tubercle. Orals com- paratively small, even the posterior one, which is central, being but little larger than the other plates. Ambulacra covered by two rows of alternating

i

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batocrixip^t:.

549

pieces, with a larger one at each bifurcation. Anus located at midway be- tween the suinmit and the peripiiery. Cohnnn occupying two thirds the width of the base ; axial canal large and pentalobate.

Ilur'aon and Local'dy. — Hamilton group, Louisville, Ky.

Tijiws in the Knapp collection at New Providence, Ind.

licmarfiS. — S. A. Miller, in his North American Geology and Palaeon- tology, undertakes to reinstate Lyon's prior name Adinocrinus cornli/rriit, which he changes into Gcnnmocrimis coniii/crus. The Species was originally described as Avlinocrhnis coniifjcnis, which Shumard, finding the name preoc- cupied b}- ILdl, changed into Adinocnmis I'ciihicl'kimn, by which it is laljeled in most of the collections. That the species was referred afterwards to a dilTerent genus, does not restore the former name.

I V-l

OennEBocrinus eucharis (Hall). riate XXXIV. Fi,j. I4.

18G3. Aelinoei-iiiKS euelidm — XlkLi.; loth l{f|). N. Y. Sliile Cal). N:it. Hist., p. 130. 1881. Geiiiiiroeriiim ciii'/iiirii — W. and Sr.; Kevisiou I'ulicocr., I'art II., p. 101 (I'rocccd. Acad. Nut. Sci. riiila., p. 335).

We were unable to obtain for examination typical specimens of this species, but from the description it appears to us that this form is very closely allied to Gnina-ucrlnHS lientiwkkiitsls. with which it agrees in the form of the base, arrangement of the brachials, and the number of arms. Accord- ing to Hall, it is said to differ somewhat in the ornamentation. The ridges which traverse the ray form a, sharp carina, with strong nodes on the first costals; while on the centres of all the other plates there are low angular nodes. Hall notices also a slight difi'erenco in the form of the dorsal cup, but this is not borne out by the description. Wo are inclined to regard this species as identical with the preceding one.

ILwhon ami Lomlitij. — Shales of the Hamilton group. Western New York.

Tjpe in the New York State collection at Albany.

ACTINOCHTNIDyl-: (Rokmktj).

(Kmi'iuli'il aiul restiictcu by W. and Sp.). Monocyclic. The lowkr iii!.\ciii.vls with well depineh iNTERimAciiiALs hetween

THEM, FOHMINO AN I.Ml'OKTANT PAUT OK THE DOHSAL CUP. RaI)L\LS IS CONTACT EXCEPT AT THE POSTKIUOlt SIDE, WHKUE THEY AHE SEPAllATEI) BY A lIEXA(iOSAL ANAL PLATE, WHICH IS FOLLOW"!) BY TWO INTEUBUACHIALS WITHOUT A SECOND ANAL. iiASALS KOKMINU A HEXAUON.

t

Aii'i/i/sln itftjw Cnvrn. Basals 3, equal. Arms biserial, branching alternately from the main divUions of the rays.

A. Axis AT TlIK KND OK A TIT.K.

1. Intcrhnifliials lyiiiinctril ir'itli the iiifi'i'<iiii/iiil(irrii/,t. II, C'(i/i/.r /ii/iril, hifrrriiiUnl a/ini'fs i/ijiri.tsiil.

Anal tnlu! lone;, coiitnil. Tho branoliinr; in tlio calj'X aliove tlio (listiclials at alternato sides from cvory second or lliinl |ihitt'. liifuiTations of tlio free arms, if any, at long intervals Acfhiofrhiiin.

Kays ])rodnct'd into ann-liko tubnlai' cxtonsions, risinij to the full lii'iglit of tlio crown, givint; olf arms from alternate sides Sti(/(inorr!niis.

Anal t'.ibe short, oxcontr.e. >'entrid <lisk largely ine- doiniiiating over tlip dorsal eiip. liays widely sepa- rated. Arms heavy, generally bifureating in the free state, the branches divergent Aiiijjiiornrrliiiis.

2. 1 i>fei'ht'tic]tiith n<it ruHtirrfi'f/ irtf/t thf ntfn'tfiiifni/'/ri-fr/s.

It. (.'ii/i/.r nut /ii/inl, iiriiis iilmiit i-ijiiSilisttiiit, ijii-i'ii '[(f i>i " inoro

01' Ivus miiti'iiiioiin ring iiroinnl thf I'lih/.r ; iiiinl tiilii' /on;/,

Cintni/. Ji'ij'iireiithins /iri/ninl t/ii' fimtiilsf'rnm ii'rri/ /inirhial

ill till' rii/i/.r ; ni'nin sini/iti'.

Arms directed upward. W'litral disk conical, gradually

passing into the tube Ciirtofi'liiii.i.

Anns very numerous, their lower portions directed out- ward, incorporated into the calyx, and forming a broad, flanging, continuous rim Tdciocrinus.

B. Anus without a tuiie.

((, .1// hifiiri'iitiims III till' nili/.r gii'i'n off from tin' fii'xt lii'iwhinl of miri'i'snii'i' orili'i'.i. Interbrachials oounccted with the interambul.acrals ; in- terspaces between the rays and their subdivisions channeled j arms arranged in groups ; ventral disk liemisplieric, anus exeeutric Physitocr'inus,

ACTINOCRINID^.

Interbrachials not connected with the interambulaorals ; liracliials from tlio diaticlials or paliiiars iii) lixti'udiul into a liroad, llanginj; rim as in Tr/ilun-iiiiis ; arms very iiunicrous ; ventral disk low, composed tliroiigliont of very small, irregular jiioccs ; anus subcentral . . .

Geoloij'ifid (111(1 Gcixjniphkdl Distribution. Number of known species.

(Open (ii;iirps iiiclicalc Amtricmi; (hose iimikcd (), Europctin.)

551

Strntorrhuia.

FoitM VTIltN.

AlilNiH UIMIi.K.

Anieriean.

o

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— 3 3<

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- 2^

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r[)per liurliiii^ton.

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Lower I)urlinj,'tiiu.

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Waverly.

Cliouteiui.

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ToUl sp.vies 7,S |. ^''''^'j

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NdTi:. — 'I'liciv urn many svnnnyiiis ainniif; tlio feriiis drsriilicd liy dc Koiiiiick mid other Duro]icaii wiilurs under ./f////ur'/7'«».« ; iilhi'i-s will have (o l)e referred to diU'ereiit genera.

Ifcnifid-s. — TIio rcliitiona of the ActinoorinirlaB ami Batocrinidn? witli othor Camcrata, and tlio distinctions between tliese two families, have been sndiciently pointed ont in connection with the Rntocrinido". The ab.sencc of an anal plate between the two interbracliials of the fir.st vow, and the alter- nate mode of bifurcation of the arms, will always distinguisli an Actinocriiioid from a Batocrinoid.

The Actinocrinidfc were a .short lived family, appearing' first in the Waverly group, and culminating in tiio large and striking forms of the

I If

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552

TIIK CRINOIDKA CAM KR ATA Or NORTH AMKRICA.

Keokuk group, beyond which no vcstlgc of them has been seen. There are about sixty Anieriean species, and perhaps twenty from Europe, where it occurs also only in the Mountain Limestone.

Fig. 1j. Acliiiorrimi'. (Exiiliumtion of llic letters ns in Fig. 12 )

\ fi i

ACTINOCRINUS J. S jullek. (Restricted.)

1S21. .T. S. MiLLKR; n riislory of the Crinoidca, p. 91.

1S14. McCcjv; SviKips. Ciiil). Kiiss. Iri'liiiid, \\ ISl.

ISli. De Koxinck; Dcsenplioii Aiiim. Fuss., p. 49.

13.j:!. Dk Kox. miil Lk Hon ; Keeher. Criu. Terr. Cub. Belf^ique, p. 123.

TS.).-). F. RoEMKH ; Lotliir.T r.cniii. (,\iisi. 3), .Tulirg. XIX., p. 2W,

18.-)7. I'll TK.T ; Traitc dc Paleont., Veil. IV., p. 323.

ISlir). JFeek and Worthe.v; Geot. liep. lllinoi.s, Vol. II., p. 117.

l'<73. Mkek and Worthen- ; ibid., Yd. V., p. 311.

1873. Ztttei, ; Handl). d. Palieontnlosie, Vol. I., p. 309.

18S1. W. and Sp. ; Hcvibion ralreocr., I'art II., p. 13S (Vrocced. Acad. Nat. Sci. Phila., p. 312).

1889. S. A. Miller; N. A. Genl. and I'aliront., p. 216.

Syn. Blairocrinm S. A. Miller; Adv. Sheets 17th Rep. liid., p. 69.

il

I

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actinocrixid.t;.

668

Calyx distinctly lobed iit the arm regions, the liiglicr orders of brachials forming, together with the ambulacral plates overlying them, five more or less prominent calicular extensions, or brachial lobes, from the two divisions of which the free arms are given oflT by alternate bifurcation from every second or third plate. The plates of the dorsal cup are ornamented by radi- ating ridges, which often meet in a node. Basals three, rather largo, forming a well defined cup. Radials larger than any of the succeeding plates. Cos- tals two, the first hcxangidar — exceptionally quadrangular. Distichals all axillary ; snpi)orting at their outer side an arm, at the inner from two to three palmars. The succeeding bifurcations take place in a similar manner; each successive order of brachials consists of two or three plates, of which Ciich axillary supports an arm at one side, and two or three post-palmars — accord- ing to species — at the other, and so on to the last bifurcation in the calyx, which gives origin to two arms. When there are only four arms to the ray, the last bifurcation is on the distichals, and there is of course no alternation. Tiie arms are given off alternately from ojipositc sides in almost the same way as the pinnules from an arm with a succession of syzygies; but in Arllii'wriiiiiH the sides of the proxin)al arm plates are suturally united with the plates which support the succeeding order of brachials. Arms biserial, and nxMpiently branching once or twice after becoming free; the pinnules long, and their proximal joints armed with a small hook, projecting from the middle of the plates. The intcrbrachial spaces on approaching the arm regions are widely and deeply depressed; they are occupied b^' numer- ous plates, which meet with the interandnilacral pieces above, and in some species take part in the formation of the brachial extensions. The anal side is the widest, containing one large plate in line with the radials, which is followed by two interbrachials ; the anus is located at the distal end of a strong tube, which rises abruptly from the summit of the tcgmen. Orals rather small and excentric. The ambulacral plates either consist of two rows of large covering pieces, which pass out from between the orals and follow the branching of the food grooves, or are represented by large single plates of a first and second order, succeeded by small covering pieces, which meet with those of the free arms. Column round, the axial canal small and pentangular. ''

DistrihuHon. — Restricted to the lower part of the Subcarboniferous or Mountain limestone. In America it makes its appearance in the Waverly group, where it is represented, so far as known, by a single species; it reached

70

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11; I]

■X

i

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11,

.(

1

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THE CRINOIDKA CAMKRATA OF NORTH AMERICA.

I

i\

v

its culmination in the Upper Burlington limestone ami Keokuk group, where it became extinct, being tlie last survivor of the family. In Em-ope it is represented at Tourney, Belgium, in the Yorkshire regions of England, and at Waterford, Ireland ; but no trace of it has been found in the higher Car- boniferous rocks of Scotland or Russia.

7i'(HiM/7.s. — The gnwufi Ac/inocn'iiKs was made by the earlier writers on Crinoids a receptacle for all — or nearly all — Camerata with a monocyclic base, ami in which an anal plate was introduced within the radial ring. This accounts for the fact that the number of species referred to it reaches nearly three hundred. The first departure from this rule was made by Austin in 184'), who introduced the genera Ampliomcrinus and PiricrliocriiiKs ; and although his descriptions wore meagre and partly incorrect, he gave well known types for both forms, .so that they could be reodily identified. Owen and Shumard followed in 1852 with Mci/lstocriniin, and F. Roemer in 1854 with Doryrrinm. Tn the same year Cassoday proposed the genus Brifwrintts, and in 1859, in company with Lyon, Erdmocr'mus. But all these genera, with the e.vccption of Mcf/Ulocrinua, were ignored by Hall, who from 1859 to 1801 described a great number of now species of this group. A niore important stop toward a bettor understanding of this group was tulvon by Meek and Worthen, who not only accepted the genera theretofore proposed, but introduced three now ones, viz., Sfrr/CDiorriiius and Stroforri'mis in 18CC, and P/i//.'<ifiicrinii.s in 1809, wliicli also arc now generally accepted. After- wards wo propo.scd the <^Qncrii Gnhiwocrinus and Tckiocriiius, nnd in 1881 the number of species retained under Actlnocrlnus, after deducting niunerous synonyms, was reduced to less than fift}'. But even these species were su.sceptible of division into two sections, as already pointed out in 1806 by Meek and 'NVorthen, viz.,

A — .spccios in wliich tlie liighor lirachi.ils, sometimes from tlie second costals wp, are

gidiiped together, so as to form five protuberant lobes, from wliicb the arms are

given off from alternate sides. li — species in which the arm bases are arranged in a continuous series around the calyx,

/. ('., the interbrachials are separated from the interambulacrals by the arm-bearing

brachials.

These differences we regard as amply sufficient for generic separation. In addition to them there is a constant diflTerence in the number of brachials be3'ond tlie costals, — the higher ordors of brachials in all .species of section A consisting of two or three plates, while each such order in those of sec-

ACTIXOCRINin.K.

555

tion B is composed of a single plute. In tliin respect the genus Aadiwcriiiio', aa now restricted to the .species of section A, dilTers from nil the other genera of the family, one or two species of iSliynii'icrliiiin excepted.

A consultation of J. S. Miller's Natural Ili-tory of the Crinoiden, p. 91, shows clearly that his description applies only to section A, lie snys : " When the arms deprived of their fingers project laterally from the sub- globose body at the sununit of the column, they bear some resemblance to the rays or spokes fixed in tlie nave of a wheel." This is quite character- istic of the typical s\^cc'ica AcliiiocriiiHs irlavuiiladact>/h(.i, v.\\{\ there cannot be the least doubt as to which group should retain the name. For tiie .species of section B we propose elsewhere the genus CKoforriiiKs.

Avtiiiocrtnu.i urmi, and A. Ilmnhnhlti Troost, are catalogue names. A. viati' ciis White, which is probably closely allied to A, kiiiiisnilpliiK, is not sufficiently well preserved for description. S. A. Miller's new goiuis Bhilro- crinus is identical with Adinocrliius as now restricted. Ilis Adimcrhius nala- licnsi.i is described from a very imperfect specimen, and the casls which lie refers to that species very probably belong to a different species.

H

m

li;i

I .*

V vt

Actinocrinus multiradiatus Shumaud. Flule LIT. Fiffs. 3, 4a, b, 5 and G.

1837. SiiCMUiri; Trans. Acid. Sci. St. Louis, Viil, I., ]i. 73, I'hitc 1, Y\<^. 5. 1858. \\\\.\.\ (iei)l. Uep. Idwn, Vul. I., I'liit 11., p. 37',t, I'hite 10, \\. 0. 1881. W. iiml Si'.; Uevisioii rnhuucr., I'liit II., p. Hi.

Cnlyx of medium size, distinctly lobed from a summit or basal aspect. Dorsal cup to the fop of the first costals slightly convex, and one fourth to one third hiuiier than from there to the base of the anal tube ; the second costals curving abruptly outward. Distichals and palmar.s hoi'izontal and rounded on the back. They form, together with the plates of the tegmen overlying them, brachial extensions of the calyx ; while the intcrradial ])lates between them follow the general curvature of the calyx. Plates of the cup highly ornamented with strong, somewhat undulating ridge.s, which in sets of from one to four run from near the middle of the plates to the outer margins, where, crossing the sutures, they unite with those from adjoining pieces, and form a number of sets of from two to three concentric triangles. The radials generally have above the centre of the plates a trans- verse node, from which four prominent ridges proceed to the basals ; three

!! i

5u0

THK CHIXOIDKA CAMKRATA OK NOIM'H AMKUKA.

1^

u

I lit

p

others pnss out to the costiil« nnil first iiiteibrnchinlM, nnd from one to three to the other phvtes; but only those of the middle series are continuous, the two at the sides which form the inner triimglcs, wlieii present nt all, being intorriipted and less distinct.

Basals large, forming a broad cup, with rapidly expanding sides; the lower margins projeeting over the top of the colunni, somewhat thickened, anil sliglitly notched at the sutures; the axial canal sharply pentangular. Radials large, longer than wide, the sloping upper faces much smaller than tlio lateral ones. First costals nearly as long as wide, scarcely half the size of the radials, and hexangular; the second costals from one third to one half smaller than the first. Distichals small, twice as wide as long, axil- lary; their sloping outer faces support an arm, which becomes free from the second plate, the inner faces two palmars (rarely one or three), of wliich the upper is axillary and gives off a single arm at one side, at the other post- palmars and two arms. Arms forty, of moderate size, simple through- out, slightly tapering, and somewhat flattened toward the extrenn'tios; the plates tr.insver.sely angular. Pinnules long, their two or three proximal joints covered with small hooks. First interbrachials a little larger than the first costals, supporting two plates, followed by four, of which the two lower are in part interambulacral, and the upper ones touch the orals. Occasion- ally there are two additional plates between those of the >econd and third row.s. Anal interradius very wide ; the anal plate succeeded by two plates in the first, three in the second, and five in the third row ; those of the l.itter, which occupy the equatorial zone, are followed by irregular pieces in the togmen. Teginen very short ; the plates moderately large, slightly convex, their surfaces rugose. Orals comparatively small, especially the posterior one, which is smaller than the others, nnd is placed at the side of the anal tube. Tube nearly central, long, heavy throughout, and frequently curving ; the plates .sharply nodose and transversely arranged. The nmbu- lacral plates, covering the calycine extensions, decrease in size outward, and arc immovable ; those of the fir.«t and second orders consist of large single pieces, but those of the higher orders of two rows of plates. Col- umn proportionally small, composed in the upper part of thicker and thinner joints, the former widest nt the top; but at 50mm. from the calyx all joints have nearly the same dimensions.

ITnrirnn ami LoniUhj. — Upper Burlington limestone, Bm-lington. Iowa, Quincy, Ills., Hannibal, Mo., and other places.

1 '

'I •'

Ml

ACTIXOCIUNID-E.

561

1*

r

Actinocrinua lobatus Hall (imt U'ditTiiKs). PIhIc LI I. Fii/s. hi, b, uml I'hik LIV. F\j. .1. ami Piute LV. F!<is. 1u, h.

ISim. Ham,; Sii|i|,1. r,m\. ll('|>. lnwn, p .•)!,

ISSl, W. mill Si', ; Ut\i»iim I'liluvici-., I'liil II, j. 1 U,

(?) Syii, Acliiiucriiiii.i miii-nriunfiit — llvi.l.; Sii]i|il, ficol. Rep. Inwn, ISfid, |i, tS.

LiU'gcr timn tlio preceilinjj specie.-*; the lobes of the ciilyx iiioro promi- nent; tlio iiiternulial .spiiecs cleei»er, ami formed into pitlike (k'piv,x,«iion-i. which extend from the upper part of the (ir.-<t interbrachiiil to near the oials, reducing the width of the tegmen, with the brachial lobes removed, to the diameter of the dorsal enp at the radials. The dorsal cup rises moderately to the top of tlie first costals, above which the brachials take an almost hori- zontal petition to the bases of the free arms. The lobes are narrower at the proximal than at the distal end, and at the back of the costals distinctly angular, their sides bomling abruptly upward to meet tiie small interbrachial pieces interposeil between them. In the lower part of tiie calyx, below the lobes, the plates are slightly tumid, having small central nodes, of which those upon the radials and costals are most prominent and transver,>iely arranged. From the nodes, sets of jjarallel ridges proceed to the outer margins; but these, although quite distinct between basals aiul radials, are more or less obscure between the other plates.

Basals proportionally large, forming a I)road cup, twice as wide as liigb. notched at the sutures, and thickened around the lower margins, Radials very large, longer than wide, the npper face narrower than any of the others. Costals small, the two together less than one half the size of the radials ; the first as wide as long ; the second as wide as the first, but shorter. Distichals noarl}' one third smaller than the upper costals, all axillary. They support at the outer side an arm, which is free from the second plate; ut the inner side three palmars, wliieh give off an arm to the inner side of tho ray, and to the outer two jjost-palmars with two free arms from the axilhuT. Arms fortv (not twentv-five as described bv Hall), moder- ately heavy, and branching in their free state. Interbracliials numerous ; tlie first as largo ns, or larger than, the first costals; the two of the second row one half smaller; there are other irregular plates overlying them, which meet the oral.s, and are in part interambulacral. Anal interradius the widest, and the plates still more numerous. The central part of the tegmen is almost flat, and raised but little above the top of the lateral extensions ; its plates

\

u ■' \f

\]

napa

6A8

TIIK C'UIXOIDKA CAMKUATA Ol" NOUTIi A.MKUK A.

convt'X. (^nils xt'imnitotl liy perisoinic pliitcs, mid larger tliuii lliu Miinoiiiiil- ing pii'ccs tlio poMturiDr one miljeeiitrdl, wider tliiiii liigli ; tliu otliers wome- wliiit liirj,'er tiiul eloiigiite. Covering fiiecex of llrst iintl Mecond orders irregular, and diirnndt to dislinguisli IVoni the superinipowed interandjidacrals, but tliose of tlie liiglier orders iiru regularly arranged in two rows. Anal tube nearly central. .

Jli'i-hm (iiiil L'ifi(ll/i/. — Transition bed between the Bnilington and Keo- kuk groups. Pleasant Grove, Iowa, Niiuvoo, Ills., and Canton, Washington Co., Ind.

Juiniirh. — The speeiinen figured by Wort' on as Acllnocrliiiis luhntua Hall, in the Geologieal Report of Illinois, Vol. VIII., Plato XII., Fig. 8, is a small example of Actiiiucrinus mnynljicm W. and Sp.

Aotinoorinus verrucosus Ham.. riatc LI I. FlijK L\i, h, c.

1S")3. IIali; Ocnl. Rep. Town, Vul. I., I'liil II , p. .">79, Tlute 10, Figs. 7a, «. IbSl. W. niKlSr.; Uovisiou l';ilu'ocr„ I'lirl II.. p. 11(1.

Svii. Ar/iiiorriiiii.t us/rriii.i M( (,'iiK.ssnv ; Ui'scr. New Spec, of Foss,, p. \3, niid Trans, Cliicngo Acml. Sci„ Vol. 1., p. 9, riiite 3, Fis. 0.

Approaching in size the two preceding species, but differing widely in the proportions of the caly.v. the greater convexity of the plates, and their sur- face markings. Calyx distinctly lobed, its height from the base to the foot of the anal tube about equal to the width at the ends of the brachial exten- sions. The sides of the dorsal cup spreading nniformly to the top of the first costals, thence abruptly outward, bringing the plates forming the brachial extensions into a strictly horizontal position. The plates between the lobes are raised slightly above the general surface of the plates bo- low, forming a low rim around the npper margins of the dorsal cup, dilTer- ing in this from the two preceding species, in which this part is impressed, and the brachial appendages are more prominent. Tegmen almost as high as the dorsal cup ; pyramidal, rising evenly from the outer margins of the lobes to the summit. Plate.s of the dorsal cup tumid, and the middle of the radials, first costals, anid plate, and first interbracbials, elevated into a promi- nent node, which, except on the interbracbials, is transversely disposed. From the nodes of the radials and anal plate sometimes two rounded ridges

II

i

A(TIN(»(«INII).K.

n.jo

*>

pnMH out to tlio IjuhiiIk, mid .«*iiigIo oik-h to tlio iiitorbmcliiiil!) ami costulu ; but those ridgi'M, if present ivt till, mo moro or Icxm obKcuro.

nuMiils nuiiloratcly large, forniiug a low ciii), wliidi is drcply notclicd at tlio sutures, and tiiickt'iiod at tliu Iowit ninrgins no as to Corni a broad lini, wliioli [irojecl.M oiitwanls and downwanls. Itadinls gciiurally a litllo longer than wide. First contal.s liaif tiie m.o of the radials, a iiltlu wiilor than long; tho necond one lialf smaller than the first, and twice ns wide ns long. Dis- tii'bal.s one, (juite small, giving ofl' from the outer side an arm, from llic inner two [laliiiars. The latter siijiiimt an arm at the inner side, and two |iost- palmars with two arms at the outer. Arm facets with transverse, im])erf(irato, articiilnr ridge. The respiratory pores small, and placed so close to the am- Imlarral o|)enings that the intervening walls arc rarely intact. Arms forty, moderately heavy, simple throughout, and biserial from the second or third plate. Regular inteibrachials: 1,2, 4, 15, followed by other plates in the tegmen ; tlio.sc of the third and fourth row placed between the lobes, and in part interambulacral. Anal plate smaller than tho radials; followed by 2, '1, 4. or G plates, and by numerous smaller pieces in tho togmen. Plates of the teginen sharply nodose and rather iinifonn in size, except the lower interam- bulacral pieces, which are somewhat smaller. Ornls and radial dome plates indeterminable. Near the arm bases small covering pieces can bo recog- nized. Anal tube almost central, largo and heavy throughout ; formed of rather large nodo.se plates, which are intermingled by small almost flat ones.

If"ri~oii ami Loculllif, — Upper Burlington limestone ; Burlington, Iowa, and Monmouth and Quincy, Ills.

'i 'Ih

Aotinoorinus soitulus ^fF.EK nnd Worthek. Phtc L V. Figs. ,7, Ga, b.

ISfiO. 5[. nnd W. ; Trooord. Aond. Nat, Sri. Pliiln., p. .I'ifi.

I5i;ii. .\I. iihJ W.l (icol. Hep. IlliiKiis, Viil. II., p, 21)2, IMiitp 15, Figs. 7ir, i.

I'iSl. ^Y. nnd Sr. ; Rcvisidii Piilirc.n-., I'liit II., p. 1 t.V

Sjn. .li'fiiiDfriiiiit rim/ii'in II.m.i. ; ISfil, Dcscr. New Sprc of Crin., p. 2.

Sjii. Ji'tiiioenniis Si/liiiiiiiii M. nnd \V. i ISfil, Vrooccd. Aond. Xiit. Sci. Pliiln., p. 13i.

Syn. AcliiiorriiiHi ll'iirLtiiiii/ii WtiiiK; 1S02 (not IsriOi Pnirood. Hnst. Acml. Nnt. Sci , Vdl. IX., p. 15.

Rather below medium size. In the form of the calyx a]iproacliing A. irrrucosvs, but the brachial extensions shorter, the interspace." nar- rower, ond the interbrachials less numerous. Dorsal cup obconical, its

i

I

.'iCO

THE CHINolUlvV ( AMKIIAIA til' Nolllll AMKUItA.

\ )

irl

fitlcH I'Ximnilin;^ ri-giilarl} I'mm flio I)iiko to lln' luii of tlio cohIiiIh, tlio Iiijilier Ijiiicliiiil^ hoii/.Diilul. W'ntiiil disk di'iue-Ni'd i'(iiivi'.\, ocoupviiig iiltoiit oiiu lliinl tlio lifiglit of tlie oiilvx. SinrMci'?* of [AhU'h Komi'wliiit vaiiiildi', Imt, an II ndo, tlio radial^ and anal |ilatu HtrongI}' nodixo, the nodes tiiin.svt'i'.-<i'1y arrauf^i'd, covorin>{ llio wlioli' .-mfaci' of the idiiti's, and i'Xltn<linjf oldiiimd;- ontward. From tlio i<idoM of tiu'Ho nodes indisiinol ridijes or anj^ulaiities pass out to tlio costals. givin>< to tlio xootion of tlio oiip an ohscurel^' jioii- tanj,'Mlar oiitlino ; similar ridgox procood to tlio liaxids. 'j'lie first intor- linudiiids aro niaiked with wry ]ii'oiiiiiu'iit ronniU'd tidioiok's, i'i,«iiig nhrnptiy at tlio middle of iIk' idates, while the higher inturbnichia!« mo nearly Hat.

Hnso short, deeiily grooved at the sutures, and notela d at tho lower margins, presenting ihieo well marked lolies, whiidi. hanging <Iowii\vard, oncloso the proximal stem joints. Ihidiiils nearly as Inrge as both costali* together, and as w ido as long. First eostids iio.xangnlar ; the second wider tliiiii long, and generally smaller lliiiii the llrst. Sueeeeding hraehiiils small, exteriorly rounded, with deep longitudinal grooves nl the sides. Dislichals all axillary, tlioir sloping outer faees giving ofl'an nrni. the inner ones ol' both ray divisions two pidmnrs. and those ngain an arm from the one ^ide, and two post-palmais fr(nii the other, of which the axillary supjiorts two arms. Anns forty (not twenty as supposed hy Hall, nor thirty as given by Meek and Worthon); long, ioundod, not branching in their free state, and not laiierlng at tho extremilies. Interhraeliial Hjnices .slightly llattenod ; they consist at the regular sides of 1,2, and 1 plates, tho latter row on a level with the arm openings, and at the nnal side of 2, ^, luid u pieces. Plates of the togmon of medium size ; tho orals, which are slightly the largest and not in contact with each other, placed at some distance from the HUinmit, Ambidiicriil plates of first ami .second orders represented by large single plates, those of tho higher orders by rows of snuill covering pieces. Anal tube central, ami of modornto si/o.

Jliin'.ivn mill l.nrnUlt/. — Upper Burlington liiiiostono, Burlington, Iowa, and at the .same hori/on in Missouri and Illinois.

Tijpcs in the (Worthen) Illinois State collection, Springfield.

t

I

ACilNOCKIMD.K.

Ml

<*9

Aotinoorinui p«modoBui iiul.

J'iitU L V. I'njx. Jit, 0.

185S. U\i' ; <li"l. Hip. I"»i'. v.. I I , I'aii II., |. tins, I'luii' Ij, Ki((v X,, /,, mu\ VUu ift, V'lu. 7. 1811. \V. uiul He. ; lU'VjM.m I'uluMVi'., I'url II., |>. 115.

Nt'urcMt to ..1, rtrnwosiis, lint of larifcr ni/o, tlii' I'lult's licaviur mid ilc- ciilcilly iiiiii'f nuiIoHu. C'al^x ii litllo lii^litr lliiiii wiili', iiiiiloi'iiil)' ^|ii'i'ailiii^ from tlio lii'oiully tiiiiicatod biiHU to tliu tup ol' tin- hi-coiii1 cuNtalM, wliunvi- tliu riiys Hpruiul ulilii|iii'ly oiilwaril. Tliu iiiti'rlii'iicliial Hpai'i'N ciirve hiiglilly iiiwarcl, iiml lonii duoply deproHsod arua.x, wliicli givo to tlio calyx froiii i\ voiitriil ivspi'ct II utroii^iy pcntaloliato oiitliiio. 'iVj;iiu'ii cliort, ik'pic.xf'i.'il convex. I'lati'M of tlio dormil cup miiMHivo nnd liiglily cluvntcd, tlio mirfiiccii risinj} oljlii|iicly from tliu Hiituro linos to nuiir tiiu ccntiu of the pliitus, and tlioncu iiliniplly to tliuir siininiits, tliuru roniiinjr conx|iicii(iiis nmluH, anIiIcIi npon tliu riidiuN and biaeliial.s arc transvcix'ly arranged. I'loni tliusu iiodcM, liroad ridgus proceed to ailjoininj; plates, two — exceptionally three — I'roiii llio rudials to the ba.xals, while there \n hut one between the oIIk r plates. Tliesu ridge.s and nodus give to the siirracu a rugose mik! rough appearance.

llasals large, projecting outward, ami forming with their lower margins a strong rim uromid the top of the column, which it* deeply notched between the plates. Radials as lung as wide, or longer; their sloping upper faces much shorter than the lateral oncH. First eostals less than hall' the si/e of the radials, nearly as long ns wide; the second as wide as the (irst, Init only half as long. Distichah' small, giving off an arm to one side, and two pal- nmrs to the other; the latter supporting on their axillary two arms, which lire free from the second plate. Distielials and palniars quite short, angular on the back, and separated from adjoining brachials of the same ray by deep grooves, formed by the incurving sides of the jilntes. Arms six to the ray. stout, long, nnd apparently simple throughout. Kegular interbrachials ; ], 2, 3, followed by ii number of smaller jtlates, which gradually pass into interambulncrals, and decrease in size upwards. The anal plate, which is smaller than the radials, is followed by 2, 3, nnd 5 pieces. There are no interdistichals between the main divisions of the rays. Orals and all nmlju-

71

I t.

m

r,iy2

iiii; < iti.s()ii)i;A ( AMKHAiA ok N(trmi ammmca,

liLciul |il;itc:^ lMr;ji^ mill r|iiii>iiiM, lli>' iiili riuiiliulMi'i'til jihil(.'H Hiiiali iiinl fliil Aiiiil IiiIk; ((.iilriil iiiiil iij)|)im'iil|)' laiijc ; il« Icii^jlli iiiikliowil.

y/'// /..'//< (//((/ A"n//./y. -- Kcukiik )4roii|i ; Ki.okiik, Iowa, uiiil Nuiivok, lliiiiiillon, ami Warnaw, III-'.

'J}//'i: ill till! ( Worlliiii; llliiiuiM Slitti' colluiil.ioii, SiJiiiij^liiM.

(

i

ActinocrinuH Lowoi Haii..

r/a/r IJV. I'uj. ,i.

IH.',S ll.li.l.; 'i.-.,l lli|,, |.,vl:,, \.,l. I , I'.ul II.. |. 'ill, I'L.lc 1./, l4p. .'„-, //. Illl. \V. mill hi-, i l(i-lnl..h l'.-illii,i-l , I'.ul II., |i III.

h)ii. Ai-liiiui-niiui hiifiiht Ihi.i.; IMiD, hu|i|il. (.i.:l. Id p. \uMt, y. 17.

A lai-j.n' '^prwIcH, j.r(;||c-lall}' (oilin! ill ii liallclicil or crilf^lli'il coiidilion, wlii'li iiMJii-'' il, (lilliciill. lo a>-(-iT(Miii Illl- ai-liial lijiiii of tin- falyx, llioii^'Ji it. fi-c-iii-i lo III- Mi-ar llial ol' .1. jn/H'idn: n.^ ; lull iIk; lilucliial (•.\li'ti.-iollM an; liii-gii, llii-ir |ilali-n |)ro|)orlic)iially Ioii;.mt, llic inliThrailiiiil <l('|)ii'>>ioiiH ili'i-|)cr, aiiil illl! li-j.Miicn lii;/lii r. I!i-hii|i'-, il lia.M i-ijjlil ailiiH to lln' lay ill )>lai-i' ol -i\. Till- oniaiiH-lilalioli i-^ liciiiiy llic f-aliii- an in llial hjii-i-icH, IhiI i-oiii<-«lial iiioic .-\ iiiiiiirli iial ; lln: jilalc-.-i aii' lliiiiiii-r, ami IIm- ci-iilral .^;;'^•.■^ U--^ (il oiiiiiMMil.

lia.-ial-i lar;.'!', loriiiiii;.^ a -li^lilly H|(rcacliti;/ rii|), a lilllc tliii-Ki-iiiil al lln; ^idcH, loiimliii on lln- Iciwcr liiai;.iiii>, anil lln: |ilari- lor tin- allai-linii-iil ol'llii! colnniii rli^ililly i-.\ia\ al'-il. Kailial.-i laifji', ii« Ion;; ai vNiilc, or loiij/i-r. j''ir^l, t:o.'^lal■i ^'iii<-ially lii-.\a;jolial, Ics.m lliaii liall lln: hi'/.c ol' lln- lailiai-'. Tin- hccom! co^lal'i .>-niaili-r lliaii llic /ir-l, iliicclcil oliiii|iii'ly outward, and in- niivili;.!; al lln- -idcM lo rorni lln- l;a^i->- ol tin- Ijiai-liial (•.\l(•ll.>•ioll^', wlii(-li from lln- di-lii-liaN i-.\lciid lioi i-/oiilall\ lo lln- lia,"-!--^ rd' lln- IVi-i- alliiy, uidrii- in>( oiilwardi. Tlic liiarliialM rjf llic lii^/licr ordiMn arc <:oiii|)aral.ivi:ly liir;;<', ^li^/lilly nodo>-i' on lln: liai-k, tin.- fuli-n iin'iii-vinff and dci:jily jji-oovcd, i-ppc- (-i;illy l)( twi'i'ii tin- main divi^'ion'', wlii'ii- lln- j/ro'ivi-H iiri' alw) wiiji-r, and linvi: ill tin- liolloin a lon^/il iidiiial rmv of lliii-i- or lour iiili-idi^ticlialx. Di.i'licliaN wiili-r iIkiii lln- co'-lals ; nil a\illiiry, ffi vili;/ oil' al llnir oiilcr t-idt'M an arm, wliirji \^ lii:i- from llic lliiid |i!alc, at, tin: inin-r two jialmai'-', wliidi fiom lln: a.villaiv .--niiiiorl. the mm-oimI nrm and t wo |io.i^t|)aliiiar -. ol' wliii-li llic ii|i|iir one l/ifiiri-alc'- a^'ain. and Hii'-I.iiin two ariiiH. 'I'lic arm- llicin«<dvi'M have not. hccn ol)-crvcd. Ii'c;^iii.-ir iiilci |,i;i(-liialH : I, 2, .'!, 8; the outer one- of the

i

r 1 :■ m

! /

A( riMt( IMNIIi.K,

003

C'liirlll row cxlcliflilij; f.ir on! on tin- liinrliiul csti'ii-ioiiH. TImti' hk; iiimimi-

DIIM OtIlIT illtl'll'inlilll lllilll'^l llllKM', lllll llic-l- lllkl; |j!I|I. ill ll|l> ll-J(ll|l!ll. Till'

iiiiiil iiii'cc Hii|)|)()rlH twi) |)liili'H ill llii- lii.-l row, Iwo in llii- ^-cidiiiI, iiiiiI liiiiiiifloilM oIIh'I' |)iiil<;M iiliovi'. N'i'iilliil ^li^k ili'[iict-hiil culivcv, ^||||||•^^ Iml, liillj^ing llliDVi; lliu nt_yM ; tin- oi;iIh hihI iilnliillitciiil |)llit(!i hliiii|ily lioilu-c ; till! iiilcniiiiliiiliirnilM iiliiio-l. lliil. 'I'ln' oiiilH iin- iiol, in cMiniact. h'\\iy h''|j.'ir iili'il liy hiniiil, Ihit, |iii'ci'H. Aniliiiiiicriil |)IiiIcm iiriiiii;.Mil in iilli-i ii.ili- ihum, \viiii:li liil'iiKMli! I'loiii II liilj/<: ii.\:ll.il y, iiii'l liiiiii M'CDiiihuy iiiiil tciliiiiy rouM towiinl llii! iiiiiiH. Aiiiil IuIm- rii'.'iily cimiIihI.

//'///•'(/// mill /,iiiiili/i/. — Krokiik ;!ii)n|); Ki-okiili, louii, .mil oilier |/l.ii:<',i in MiNMOiiri iiiiil Illinois.

ActlnocrlnuH Jurohiih IIai.i,.

/'/-(/,; A/ V. rii/. I.

)m;ii Ham.; Su|,|,I (ii.,!. Ilip l.nm, p ■)«.

IH-I, \V l.ri.l ^)-. ; l(.vni.,ri l'.ili.'.,ri , |'i„l 1 1 . |,, lU.

A liirj."' Hjii'ci'"', !il-o ;i!w;iV'i Counil in ii (•iii'-lii'il I'liiiililion, i-o lli;i( ilH follll (■lllJliol. Ill- lM-cni;it('i\ 1I--CI-I Ininiil. Il hii-Iiih (o In; |jciili'>t lo ,1 l.nini, wliich it. rcH«'liil)!i--i in tlii; noiN' ol oiii.nniMil.ilion, ImiI Iioiii iiji|ii;ir:iiii ■ llic ciilyx Ih iiioio clonj.'iili', llii- pliiliH lliiiilHT iimi inoir I'Viiils' |i|ij|/oi I loiiiij, till! Iiriidiinl cvli'li-ioiiM Ii'-h. pioniini'iil, llii' iiilriliiiirliin! -|i;ii-i- coii^iilciiil/iy iiiinowrr, mill llic lii;.i|iiT Iniirlii.-ih ol tlii- i"ilyx iniuli fiioihr iiiiil .«ni:illi-r f.'fiH'i;illy, inilii-ulinfj; ill o l|i:il llur ;iriii,^ wi'ii; iiiiicli lljiiiiii'r. I'hili'- convi'X, tliiviMMi-cl liy liiljfi'H ' iiicli liiM:t. ill lioili'M 111. Uii; rciiliiH ; iin- lioi|iv>r ol IIh'

llnlilllM, COllnl.H, (li.'ll.icllHiM lllll] IU|!ll |ll;il(! I III nsVIT>^<', lilO.'^l; ol' ll|i- illll'l

lifin'liiiilM loiiiid. From llio-c of (Ik; rmliiil.H four liil^fcH piiH-i ilouii lo lln' li;i.".'il,s, Uiiim; oIIicih ii|HViiiil lo IIh' (ir«l cohtiilH, iiliil ^olll<•lillM■M llii> >-:\\nf iiiiiiiIht niim to lliit hcioiiiI co^-IhI-i, IhiI, iIiiti.' i^ ii'^vit iiiori' lli.iii one riilL'i-

hi'lWI'Cll (III! oIIhM' pl.lll'M.

Uityiiln Coiinili;.' a wiili- ciiii, willi ii i-lij.'lilly [iroji-cliiij/, i-inoolli lolhir al liic lowiT I'liil, mill ili-i'|ily yioovi'il 111 llii- iiili-i liawiil hiiIiui-h KmliMN anil liolli co-lals lonjfiT lliMli wiili'; lln; lalliT iilioiil oiii' liiill' iIm' ;-i/i' of iin- railials. iJi^liclialn u Hull; kiiiiiIIit lliali (lif co^IhIm, ln'arly iih loiijr iiHwiili-, anil all Mxiliaiy, j/iving oH' an aim lo oiii- I'iili', iiiiii Iwo |pnliiiaiM (o (Ik; o(Iiit. Till! (wo lower (i.\ci| arm plad'H are iioiio-^c, mm wiile an lon^.', ami a-^ lai'i' a?* (III! iiulliiaiM ol' (lie o)i|io>ii(i' ^iile, ol' wliicli (lie M'coliil iH a.xiilaiy, mii| givef

i !

I

!)

'-1 J

5C4

TIIK CRINOIDEA CAMKIIATA OK NORTH ASIERICA.

t)lT miotlior arm iiiul two post-iiiilniiiiM with two arms, Tlio secoml arm is free from the sicoiul \)hvU', tlie two iipinr oiu's from aliovc tlic first. Ilij^lior bniciiiiils sopiiniled hy ck'i'j) longitudinal grooves, formed hy tlio liiteral in- curving of tlio respective plates; post-palmars very short, reseinhling free arm joints. Structure of the arms unknown. Interbradiial spaces narrow, tlie plates of the regular sides arranged: 1, 12, ii, o, 3, 11; the anal plate, which is snndier than tlie radials, is followed hy 2, ;5, 4, and several higher rows, of which the exact arrangement cannot he ascertained. Interdislielials three or four; rather large. The form of the teginen is given by Hall as "conical, rising gradually from the arm bases to the base of the central proboscis." This appears so in the llatteued specimen, but we doubt if it.') natural form was conical. IMates aroinid the .summit moderately liirge and tuberculiform, those covering the brachial extensions .somewhat smaller, the iiiterambulacial pieces still smaller and but slightly convex.

lliinxiin iiikI Liirti/i///. — 8ame as last.

'J'^jic in the (Worthen) Illinois State collection.

Actinocrinus multiramosus w. ami Sr. (mov. .sjicc). ri«tc LIH. Fi(j. 1, uiiil PMc LV. Fi,j. 3.

(■-) Sjii. .l.-liimfriiiiit r/riiii,/i\- S. A. Mn.M;ii, 1 ^'.Ml (nut I,_voii 18,V.)) ; I)i".c. Ni'W Gi'iii'ni iiml Spec, iif Kcliiiiod., )v'.>,-|, IMalc.T, rii; 1. ;iii(l I'lMi'Ti, Vig 1.

A large species of the type of A. Lmrr! Hall, with which it closely agrees in the mode of orniimcntatiou; difl'ering, however, in the more slender form of the calyx', the nundjer of palmars and distichals, in being less dis- tinctly li)')cd, and in having within the calyx three bifurcations in jdace of fiMU'. Calyx- obconical to the top of the first costals, broadly truncated at the li.isc ; the distichals ,nnd higher orders of brachials given oft in clusters, bending outwaril and ()l)li(piely upward to the bases of the free arms; the interliriichial s])iic('s doeidy dcprc.x.sed. and the interspaces between the main I'ivisions of the ray deeply grooved. Ventral disk dei)resscil-convcx, occupying from one fourth to one third the height of the calyx, and sur- mounted by a strong tube which rises abruptly from the sunnnit. Plates of the dorsal cup heavy and convex, their surfaces covered with sets of well defined ridges which traverse the suture lines, and also b}' large nodes. The nodes are placed near the middle of the jilates, and those upon the

Vi

»i

ACTINOCUIMD.K.

505

riidinls, first costnls nnd aiiiil pinto arc transversely elonj^ate, and oceupy nciirly one fourth the snrfaco of tlio plates ; wliilc tliose upon tlio inter- l)racliials, which liavc a circular outline, are iiroportionnlly smaller. There are jj;enerally three ridi^cs hetween the ra<lials, iiasals and eostals, hut these arc not, continiions, e.\ten<1inff only to the niai';fins of the nodes; two proc(>ed to the first interbraehials, while the other plates up to the brachial extensions are connected hy sinj^le rows. iSutnre lines distinct.

Hasals large, forming a hroad and deep cnp, which at its lower margin is distinctly notched ; the lower edges of the plates expanding, and forming a smooth, thickened, trilohate rim, which stands out cons|)icuonsly from the column. Radials as wide as long — in very large specimens proportional!}' longer — more than twice as large as both costals together; the lateral faces longer thiin the sloping upper ones. First costals nearly as wide as long, and hcxangular; the second very short, sometimes less than half the length of the fh'st, and ol)lifpiely angular above. Distiehals small, all axil- lary, giving off from one side an arm. which is free and biserial from the seconil plate, and generally simple throughout: from the other side three pahnars, which snpjjort two arms, which both bifurcate once or iwice in their free state at some distance from the calyx. Arms long, moderately heavy, rounde(l on the back, and niMirly as thick at the distal end as at the proximal. Arm joints short and slightly convex. Piiniules rather thin, and only their three or fom' proximal joints are provided with small hooks. Interbrachials; 1, 2, ."), followed by a nnndjer of others in the eipiatorial region; the first as large as the first costals, those of the second anil third rows smaller. Anal plate somewhat shorter than theradials; supporting two ])lates in the first, three in the second, and four to live in the third row. 'rcgiuen compo.sed of slightly convex, moderately large pieces. Orals in contact, the j)osterior one small and placed transversely; the others larger than any of the sur- roimding plates, but otherwise not distinct; tli(>y are elongate, and narrowest at the lower en<l, leaving notches, which enclose the first radial dome )ilate. Tlie latter is followiMl ])y two plates of a second order, anil these by alternate rows of miiuite covering pieces. .\nal tube extremely long, extending far out altovo the ti])s of the arms, and heavy throughout ; the plates strongly tnbercidous ami sharjily jiointcd at the top, some of them larger and sub- spinous. Column largo at the \ipper end, but tapering distinctly downward. The nodal joints near the calyx considerably longer nnd wider than the intervening ones, and angular at the edges, but gradually with their decrease

' h'

n

1 1 '.fiil

n»

h

Sf\i

uCO

TIIK CRINOIUKA CAMKRATA OF NORTH AJIKRICA.

in witUh they grow shorter and cjlindricul, wlule the others rehitivcl}' inereuso iii size.

7/('/v.u/t and Luciilitij. — Keokuk group ; Indian creek, Montgomery Co., and Canton, Wusiiington Co., Ind.

Tijpeis in the collection of Wachsmuth and S[)ringor.

Jiemarks. — Of this large and beautiful species we obtained at Indian creek and Canton over forty specimens, most of them in excellent preserva- tion, with the arms attached; and it is very remarkable that nearly- one half of them have either a I'hdijcLiiix attached to the teginon. or a specimen of Oiajdutstcr between the arms and coiled around the anal tube. This, so far as we know, is the first instance in which a I'/at^cmin has been found in contact with a Crinoid with a long anal tube ; in all cases heretofore noticed the Crinoid had an anal opening directly through the tcgmen, and the Gasteropod was fastened invariably with the anterior portion of the slicll over the opening.* This led to the supposition, for which there seemed to be good reasons, that the Mollusk obtained its nourishment, in part at least, from the excrements of the Crinoid. This, however, was impossible in the case before us, where the anal tube, with the anus at the distal end, extends out far beyond the tips of the arms, and, .«o far ns observed, bends abruptly to one side, so that neither the opening nor the refuse matter coidd have been in contact with the Mollusk.

In more frcrpient association with this Actlnorriiinx is the Oiiijc/i(ufir, and it is worthy of note that this specic-.-i of Ophiuran is rarely- foimd b^' itself. Nor has it Ijcen ob.«erved at Indian creek on any of the other Crinoids, while at Canton it appears also on most of the specimens of Sri/tidicrimiK ro/nishi" (Hall), a species with a large ventral tube, and the anus located far down at the anterior side; but with this exception we have not seen it on any other species. The fact that this Ophiurid is oidy found associated with certain species, iiud there always under similar conditions, and the frequency- of this occurrence, would seem to indicate that the posit io!i between the arms of these Crinoids was its favorite resting place, in which it either found piotec- tiou, or some special facility for obtaining nourishment. Nobody, however, who is acquainted with the nnntoniy of the Crinoi<ls, and their mode of liv- ing, will entertain for a moment the notion that the Crinoid prej-cd either on the Ophiurid, or on the Gasteropod, as .suggested by the earlier writers.

• See Synopsis of Aiiier. Carbon. Ciilypu-aidic. By Chnrlcs R. Kcycs. Proceed. Aciid. Nat. Sci. Pliiln, 1890, p. 151."

■*^»

ACTIXOCRINID^E.

507

It is quite probable that MWhr'ts Stci/diiocriniis BimUcti* belongs to this species. Its arms are given off in exactly tiio same manner, and it lias the same style of ornamentation, only tiie calyx appears to be a little shorter timn is usual in that form. We doubt if it is a iSltjundcrinus, for the brachials of caeii ray, according to the figures, are in sutural contact laterally to the base of the free arms, instead of being given off from tho sides of tubular appendages extending to almost the tips of the arms. It is also possible that Miller's Ac/inocriiiKS gvandls is id'jntical with our .species. His description is insudicient for accurate comparison, and his figures show the rays only to the first palmars. Besides the name was preoccupied by Lyon in 1859.t

Actiaocrinus magnificus w. and Sr. (nov. spec). riulc LIII. Fhj. 2.

Syn. Artlmmmm loljiiliis 'WoRTnKN (not Hall), IS'JO, Gcol. Hep. llliirois, Vol. VIII., Tlnte 12, Figs. 8, 8ff.

As large as the preceding species. Calyx apparently higher than wide, broadly truncate at the base, tliglitly constricted at the top of the second costals, and more deuply at the interbrachial spaces. The brachial lobes directed obliquely upward, not very prominent, and beginning from the upper end of the distichala, so that there are actually two lobes to each ray, separated by a deep sulcus, with a few iutcrdistichals at the bottom. Plates of the dorsal cup proportionally thin and .slighll}' convex, their surfaces marked by ridges, which are not mere surface elevations, but folds in the substance of the plates, and which gradually disappear as they pass inward. The surface of the ridges is covered by rows of obscure nodes, which produce a beautiful ornamentation ; the middle of the jilates is smooth or slightly tumid, except upon the radials, which have low, transverse elevations, from which three or four parallel ridges or folds pass out to the basals, while there is generally but one between the other plates.

Basals very largo, forming a deep and broad cup, almost as high as wide at the bottom ; the lower end not thickened nor projecting over the top of the column. Radials large, as long as wide, or a little longer; the costals one half smaller, hcxangular and heptangidar, the second one nearly as lirge as the first, and both as long as wide. Distichals all axillary, slightly

» ,\ilv. Slippts IStli Hep. Gonl. Siirv. of Iiiiliaim, p. 27, Plate 4. t -ViiKT. Jouni. Sei., Vol. XXVlll., p. 21C.

m

' :

M

568

THE CUIXOIDKA C'AMKRATA OF XOUTII A.AIKUICA.

fi^

!H5;

^^1

convex loiigituJinally, one foiirtli Miimllcr lliaii tliu coMtiils, ami a.s wide as loiiy. Tlioy support at tlioir outer siiles an arm, which fioni the second or thiril plate is free and biserial ; and from the inner Hide three pahnars, wiiieli give off two arms. Tliere are six arms to each ray from the cal^x, but tliesc generally branch once again in their free state, rarely twice. Arms not quite as long and stout as in ^1. muliliwiiosus, and more rapidly tapering; the l)innules stronger. The latter are composed of eight or nine very long joints, of whicii only tiie two proximal one-i have hook like processes. Rognhir interbrachials: 1, 2, 3, 4, 3 — sometimes three in the second row — the first larger tliun the costals, the succeeding ones decreasing in size upwards. Anal plate a little smaller than the radials, and followed by 2, 3, 5, and numerous other irregular plates. Tiie form of the ventral disk cannot be ascertained, botli type specimens being Uattened, but it was probably de- pressed conical. The plates are rather large, strongly convex, rounded at the top, and nearly uniform in size. Nothing is known of the anal tube. CoUnnn very large near the calyx.

Iliir'tzim and Lwalit^. — Keokuk group ; Indian creek, Montgomcr}' Co., Ind.

T//JWS in the collection of Wachsmuth and Springer.

Juinar/is. — Tiiis species differs from the preceding one, and all others of tlie Keokuk group, in the thinness of its plates, and in having the ridges upon the .surface produced by folds in the plates. The second costals are much larger, and while in the other species the brachial extensions begin above or below the second costals, they commence in this at the top of the distichals.

Actinocrinus Orifflthi w. ami Sr. (nov. sjicc).

P!afc LIT. Fir/. 7.

Of medium si/.e. Calyx higher than wide, tiie brachial extensions nar- row ; interspaces wide. Dorsal cuji throe times as jiigh as the ventral disk, decidedly swelling across the middle of the radials and anal plate, whore the section is distinctly angular, and wider than at the top of the first costals. Plates rather delicate, covered with ridges, which meet at the middle of the plates within a small node. Tiiere are four such ridges between the radials and basals, of which the two miildle ones are the most conspicuous ; one or two form a continuous ring around the radials and anal plate, while tiiero is

4

«p»

ACTIXOCRINID.E.

509

4

M (^

generally but one between the other plates ; none, liowcvcr, above the nec- ond costals and second intcrbrachials. The ridges passing up the costals are most prominent, and the plates themselves longitiidinally angular, their sides being almost even with the flattened interbrachial areas, which gives to this part of the calyx a peculiarly angular aspect.

Basals large, forming a deep cup expanding at both ends, the plates hav- ing a projecting rim or transverse ridges around their lower margins, which, being truncated toward the sutures, give to the lower face of the cup a tri- lobate outline. Radials large in proportion to the plates above. First cos- tals less than half *.he size of tlie radials ; the second one third shorter than tlie first, and directed obliquely outward. Disticlials all axillary, quite small, angular on the exterior, their lateral eiuls bending inward. Thcj' support an arm at one side, and three palmars at the other, above which there aie four more bifurcations, all taking place from the third plate respectively, giving off an arm to one side, which alternates with the arm of the preceding order, except the upper series, which supports two arms. The main arms, as well as their lateral branches, are quite delicate, the foi'mer uniserial to the fifth bifurcation, the latter biserial from their origin. Regular interbrachials : 1, 2, 4, followed by a few smaller plates, which arc on a level with the arm bases, and rest against the orals. Anal plate considerably smaller than the radials, and supporting two plates in the first row, three in the second, and five or six in the third. Interdistichals unrepresented. Tcgmen depressed- convex, with a strong anal tube rising abruptlj' from the summit ; the plates tuberculous. Orals larger than the interambulacrals, and separated from each other by the ambulacral plates, which are large, and pass out between them in two Avell defined alternate series, diminishing toward the arms, and branching oiitward. Column of moderate size ; the nodal joints somewhat thickest, and rounded upon the edges.

Iloyivon (iml lAirafiti/. — Upper part of Upper Riu'lington limestone ; Burlington, Iowa, and Pleasant Grove, Iowa.

Ti/pcs in the collection of Wachsmuth and Springer.

JiniifirJi's. — This species in its arm structure approaches the genus Sle- rjai)ocrimi>i, and is also interesting for its regularly arranged, largo covering pieces, which pass out between the ambidacra. It is named in honor of Dr. Horace 0. Griffith, of Burlington, who, with a liberality for which we have been often indebted to him, presented us one of the type .specimens.

73

~! ».»

Kt

t

070 THE CRL\0IDP:A CAMERATA of north AMERICA.

(P) Aotlnoorinua ohouteauensis s. A. :mili.kr. IHak XL VI. Fiyx. ILi, b.

1S92. (}) Aelimcrlniii ehnHlniiirnaix — ^. A. Mli.LEli; Adv. Sliccia ISIh Rep. Gpol. Sun-. Iiidmiin, p. 18, I'lulu 3, Figs. 0 luul 10.

Of medium size. Calyx ns wide ns liigli, the dorsnl cup three times as liigli ns the disk, pentanguhir at tliu arm l)a,ses ; the sides very slightly con- vex to the top of the co.><tai.s, then rapidly spreading to the arms. Plates without ornamentation, convex and a little tumid ; the suture lines depressed.

Basal cup moderately large, gradually spreading ; the interbasal sutures well defined ; axial canal large. Radials ns long as wide (one of them in the type n little wiiler than long) ; the lower end of the two heptagonal ones dis- tinctly angular. Costals considerably narrower than the rndials, nearly ns wide as long; the first hexanguhir; the second generally hexnngulnr, nnd partly smaller than the first. Distichnls one, small, twice ns wide as long. Palmars one preserved in the specimen, very short. Arms apparently four, the arm openings directed obliquely upwards nnd nrrnnged in pairs. Regular intorradials 4 to 5 ; decreasing gradually in size iipvvards. Anal plate as long as, but narrower than, the radials, supporting 2, 4, nnd 2 plates. Ven- tral disk convex, the plates lnrg>< and nodose. Orals largo, nsynnnetrically arranged, the posterior one smaller than the others, nnd pushed in deeply between them. Ambulacral plates three, large, two of them of a second order. Intcrambulacrals three or four, in contact with the Interbrachials. Anal tube subccntral, its length imknown.

Ilirizm and L"caJlli/. — Referred to tlie Chouteau limestone, near Sedalin, Mo. ; but the color of the fossil and of the matrix leaves but little doubt that it came from the Lower Burlington.

Ti/pc in the collection of F. A. Sampson.

licinarh. — This species was described from a single specimen, which had only the caly.x preserved, and the ventral disk was partly covered by matrix. On removing this, we found Miller's ideal figure of the disk (his figure 10) to be incorrect, inasmuch as the so-called large jjlnte ndjoining the posterior oral is only the base of the aual tube, as shown by our figure.

I

I

^

ACTrXOCRIXin^E.

571

AotlnoorinuB tbnuisoulptus M>riiF.s\Kv. .'c L r., F'tij6. J,a, b,

1S59. McCiiesnry; Descr. Nrw Sprc. riilimz. Foss., p, 15.

1S(17. McCiiK.tNKv; Triuis. Cliii'. Aciid. Sci., Vul. 1,, p. II, Pluto 5, Fig. 1.

1S81. W. mid Si'.; Ucvisidii I'lilu'ipcr., I'url II., |i, 1 Hi.

Syii. AcliiiofriiKiii f/ihri.i H.ill — llljl ; licwluii Juuni. Xat. Hist., V(j1. VII., p. 2*5.

A moderately small species, wliicii, in tlie ilelicaey of the plutoH of tlio calyx, the beauty of their ornamentation, the Hpinil'erou.s character of the plates in the teginen, and the long hooks upon tlie pimnile joints, reminds us of certain forms for which we have proposed the genus Cwtorrhuoi. The calyx, however, is distinctly lobed, and the arms are arranged in clusters, which arc separated by wide and deep depressions or grooves extending far up into the ventral disk, and the upper bifurcations of the ray take place from two successive palmars. Dorsal cup semigloboso, triuicate at the base, with a small rim around the lower margin, the sides convex to the top of the distichals, thence slightly more spreading to the arm bases. Tegmen almost as high as the dorsal cup, sulipyramidal ; cross-section at the arm bases broadly ([uinquolobatc. Plates of tlie dorsal cup slightly tumid, covered by radiating ridges with undulated edges, wider at the middle of the plates than at their margins. The ridges passing up and down the radials and brachials considerably the strongest, dividing the surface of the calyx into five well defined fielils, which extend from the basal ring to the ba.ses of the free arms, and enclose a well marked star at the four regular sides, wliilo the anal side contains two somewhat smaller stars with seven rays.

Ba.sals short, the projecting rim subcircular or obscurely trilobate, accord- ing to the greater or less depth of the sntural depression. Eadials from one fifth to one third wider than long. First costals half the size of the radials, quadrangular, and nearly twice as wide as long; the second hep- tangular, wider and longer in proportion, obtusely angular above. Distichals rather small, all axillary, giving off an arm to the outer side, and two small palmars which support two arms to the other. Arm facets small, but the ambulacral openings comparatively large. Arms six to the ray. slightly angular below, gradually flattening above; the tips incurving. The four proximal arm joints are in single series, as long as wide, rnd even longer; they are cuneatc, and each one has at its upper end from its longer side

M I I

^

\ i ; »',

672

TIIK CIUNOIDKA (A.MKUATA Ol' XOItTII AMKIilCA.

a lateral projuelioii, or Mort of flongate iiodo, wliicii .ntaiids ohjiinioly up- wanl, ami gives to the lower part of the anus a zig/ag outline, 'i'he Hiicceeding plates are biserial, and of these the three or fonr lower oneM nro considerably higher than those above. The upper margins of the arm pieces project slightly over the lower margins of the succeeding ones, the sides are serrated, and the lines of union between them somewhat waving. The three or foiu' pro.ximal pinnule joint.s are provided with moderately long hooks. Regular interbrnchials : 1, ii, 2 ; the first very largo, rising to the middle of the second costals, the two of the upper row quite minute. Anal plate as long as, but narrower than the radials, followed by 2, .'!, and .'J pieces. Interdistiehals one. The grooves between the rays extend up almost verti- cally to one half the height of the tcgmon, and are paved by rather large, flat pieces ; while the orals and aml)ulacrnl plates are ,«piniform. Orals pushed out far to the anterior side ; they are comparatively small and in close contact ; the andnilacral plates nrranged in alternate rows. Anal tube nearly central, moderately large, and composed of spinous plates.

llur'r.on and LcrnUti/. — Lower Burlington limestone ; Burlington, Iowa, Sedalia, Mo., and Lake Valley, New Mexico.

Aotinocrinus gracilis W. mul Sr. (nov, s)icc.>. Flute L VI. Ft,j. 11.

Approaching ./. (tiuiisctijjitus, but a smaller species, and having a much larger number of arms ; also the ornamentation of 'he plates more obscure. Dorsal cup bowl-shaped, the sides to the top of the aLildials slightly- convex, then bending abruptly outward ; the plates a little tumid, covered by faint radiating striic and well defined ri<1ges, the latter following the rays, and forming deep depressions at the interdisticlml spaces.

Basals .small, with a slightly i)rojecting rim. Badials one third larger than the costals, ami both wider than long. Distichids 2 X Itl Three bifur- cations occur in the calyx, and one or two in the arms, all taking place from the second plate, nnd all above the first axillary from one side only, the oppo- site sides giving off a free ai'm. Arms from eight to ten to the ray, quite slender, a little wider at the upper end than at the lower ; the three or four proximal plates of each arm long and cuneate, and their widest sides, toward the upper end, provided with a short lateral node, which gives to the lower

ACTINO( . vin.T:.

67%

liiut of llic iinii II zigzag oiitliiio. Tlii' Wn/i'v jmrtn 'lie iiriim Im^o seimn.! BiiluM, iiiul uio coiiiposiMl of two Horiea of minliTiHi'l- long piec lli'^iiliu

iiiterbriifliiiils : I, 2, li; llie iiiiiil pliitu t'ollowcil h; .. ;5, anil o , aes. liiler- (liMtiflmls oiiu, largo. N'eiitral disk not vi^iljlo in ih. .-•pocMiiiefe.

Ilurl.von mill f.iinillli/. — fiOwiT lluilington linU'siont? ; Bmliriirton, Towa.

7//y(t'.'* in tlio MuHunni of L'ouipiuntivo Zoiilogy, iiiul ui the (•oliuctioii of Wnehsniuth anil Springer.

Actinocrinus tiiboroulosus w. mid Sr. (nov. siioc). rUtc LII. Flija. 8n, h, c.

Of (Iio type of ^1. toiiiiseii/jiliis, but soinowliat larger. Calyx a little higher than wide, the dorsal cup considerahly Hhorter than the tegnii'n. Plates rather thin, the Murfacc slightly convex, and ornamented by ^^erief of i.>(olated node.s of varioii.s forins. The middle of the plale.s is occupied by II conical, sometimes rounded tubercle, which is surrounded liy elon- gate nodes, directed one to each side, with their longer dii\uieter toward the margins of the plates. From the miildle of tho second costals up- ward, sometimes even from the radials, the nodes are set close together in rows, and form high and sharp knife-liUo riilges with serrated edges, running to the bases of the free arms.

Basals short, wider at tho lower margin than at the upper, at tho latter surrounded either by a, thickeneil collar, or by a row of conspicuous nodes, of which there arc generally three to each plate. Radials one third wider than long. First costals half the si/o of tho radials, and quadrangular ; the second a little wider than the first, and hcptangular. Distichals and pal- niars keel-shaped ; the former smaller than tho costal.s, and once and a half as wide as long ; the latter still smaller, and tho angularity extending over tho entire width of tho plates. Arms three to each main division of the ray, or thirty in all, given off in the usual way ; the proximal one from tho outer sides of the distichals, tho two others from the second palniars ; they arc long, Hat, wider in tho upper part than at their bases ; the lateral mar- gins serrated. Tho four proximal arm plates are single, ver}' high and cu- neate, a thorn-liko projection extending out from their longer sides. 'J'he plates, ns the arms become biserial, are short, and each one is covered with a transverse row of small pustules. Pinnules long, and to one half their

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574

TllK CKINOIDKA CAMKU.VTA tH' MUMII AMDlik A.

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k'ligtii |>ru\i(lcil witli i^liui't liookH, Itcgnlni' iiiti rlxiicliialH : 1, '2, li ; tin.- fii'Ht iiliiiuMt 1114 lai'gu i\» tliu rittliuls ; the (iliiti .s ol' the u|i|ior luw inteiluik- ing with \Uo>m I'luiii the teginen. Tlie iiiml piece itt I'ulluv.ud L^ '2, 3, iiiiil '1 [iliito!*. liitenli.xtiehiiU one. Tejjnieii HJiiMt, tlie inteniiiilHiliii'niI iiliiten mid orals Hut, all of iieiuiy the >aiiiu size ; the uiiiljuhtcml pieees tlie hiiialier, a little convex ami Ibrnieil into ridgen. Anal tube of ineiliuni F<i'/.e, the (ilatcM covered with ii niinnte central tiiherde. I'ohinin moderately' large, the nodal joints widest, their edges convex, and liordercd liy small nodes,

lloi'iz'iii ami /.I'liili/i/. — I'juier lliiiliiigton limestone; ]turlinglon and Pleasant CI rove, Iowa.

Ti//ii'i in the collection of Wachsmnth and Springer.

Ji'iiiKii/,". — This species dilTcrs from ^1. /tiniisiii/jiln.s. with which if has its closest ailinities, in the mode of ornamentation of the dorsal cup, die wider interspaces hetwceii the rays at the arm regions, ami in having Hat instead of si)initt'rous plates in the tegmen. It id»o occurs at a dill'erent geological horizon.

Actinoorinus daphne Ha it.. J'Mv L VI. Fiij. I.

l^i'it. llM.l.; Kill U(|i. N. Y. filiilc Cab. Niil. lli»l., p. 5'J.

b;.i. llAi.i,; (i.'.il. tSun. (Iliiii, I'liWunt., Vnl. 11 , I'ml II., p. lOi, I'liilc 11, \\. 11.

llM. \V. iiihl Si'.; Itrii-iuu riiliniiT, I'ait II., p. li:t.

Calyx oF medium size, its exact form indeterminable owing to the crushed condition of the specimens ; the base truncated only to the width of the column ; the rays but slightly lobed ; the arms given olT in clusters as in A. Iiitiii.'<fii/^i/iis, with moderately wide inter.-jiaces between the rays. Plates ratlier delicate ; their siirfico marked liy radiating ridges ruiming from the centre of the plates to their margins, where they meet those of adjoining plates. The ridges passing up the radials and brachials, and down to the busals, somewhat more prominent.

Basals rather large, forming a spreading cup with a wliglitly projecting, narrow rim around the lower margin, which is readily taken for the upper stem joint; interbasal sutures indistinct. Radials longer than wide; the costals wider than long; the first hexagonal, smaller than the second, and less than two thirds the size of the radials. Distichals smaller than the first costals, supporting at one side an arm, at the other two paliiiars with two

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nriuM from tlio nxlllnry. Aiiiim nix to tlio rny, ronmU'il on tlio Imck • iiiul itliglitly tiipi'iiii;.', hini'iiiil I'loiii llio tliinl pliitc up. I'iiiinilff* fXlriMin'ly lciii>r, iiiiil to tiL'iii'ly tlii'ir full Icii^ili |iniviil('il willi hhuiII iKink.H. wliicli -ll^liily ovi'i'lap tliu iidjoiniiig piiiinilu iil)ovt>. Hc^iilar inlorlxiicliiiiU: 1,'J, ^; tliu luiul pliitc followi'il liy U, ;j, and '.\ platon. Structure of tlio vi'iitral ili^'k uu- kuiiwu. Alia! tul)o ioMff, ."It'iiiiir in the up{u>r part, ami roinpo^oMJ ol' Miiiall coiivrx pii'ccM. C'oiinnii ol" more than uvrragu ni/.u ; tlii' iioilal joints pro- jecting, iiml rouiulcil at llu'ir outer tiiargiu^.

lluvhon ami /.ocnlili/. — Wuverly group ; IJiihCitiil, Ohio.

T'/fifs Id the New York .State Cahiiiet at Aihany, N. Y.

lii iiiiiy/,.1. — Thi.i and the two preceding fpecien Ibriu u lillle group hy tiK'niHolvc". apjiroacliing in nonio of their charactern Curtoci'iiin.i ; hut they niiiMt 1)1' referred to .[rlliincmnn, \\A the arms of the dillerent rnyn nro arranged in groups, «lii<'h are wparaled liy a muulier of iuterhraehial plates, and the hil'urcations ahove the di^liclials take place from the .sec- ond phitu uf each order, and nut from the lirNt as in that genua.

1

II!

Aotinoorinus agperrimus ( ^r. and W).

I'hiii' A A'. /■'/;/ V. .', iii„i a.

UrtO. ,1/rn/i:iriiiiti (^) n'pi-rrimiit — Mr.KK anil VV'urpiKV i I'rnrcrd Aoiiil. Xiit Sri, Pliilii , p. IftO. Also

(ircl. K.'p, lllin.il«. V..I. v., p. ■■Hit, II.IIC 8. Kli;. ;t. ISSl. .l,'/iiiocriiiiiii (I'liiTriiiiiii — \V. iiiiil ?*! Hfvisiuii I'liliiucr , I'lirl II , |i. 1 li.

Calyx of medium si/.o, urn-^'mped, its width at the arm hnsos criunl to its length. Dorsal cup oljconical to the top of thecostals; the distiehals and the Hucceeiling lixed hraidiials spreading hori/ontally, hut without formitig a continuous rim, there heing deep intcrradial grooves, nn<l smaller ones ho- tween the main branches of the rays. Plates almost Hat to strongly convex, their ornamentation somewhat variahle. Figs. !j anil 0 representing the ex- tremes, and the typo figured hy Meek and ^Vorthen an intermediate form. In all these specimens, however, thcro are ridges radiating from the centres of the plates (o adjoining ones, three generally hetwecn the radials and hasals, and one between the other plates.

nasals three times as wide as high, deeply grooved along the sutures, and distinctly lohed from a dorsal aspect; the lower edges scalloped and

* A (latteuiug of the arms, as doscribcd by Hall, docs not exist in niiy of nur spccliiii'iis.

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570

THE CRINOIUEA CAMEIt.VTA OF NORTH AMEIUCA.

sliglitly projeutiiig outward ; axial canal very Miiall. Uailiul.s and anal plate nearly or fully as long as wide. Tirst co.stal.s one third smaller tlian the radials; (he second costals narrower than the first, and smaller generally. Higher brachials gradually decreasing in size iipward, each one sujijiort- iiig an arm at one si<le, and the upper one two arms. Arms normally eight to the ray; .'small, to judge from the .size of their facets. Eegular intcrbrachials : 1, 2, 2, again-t 12, 3, 2 at the anal side, followed h}' two very .^mall pieces hctwt.'en the lohes. Interaxillaries one, which, like the interhraehials, meets with the plates of the tegmen. A'entral disk le.-^s than oui' third the height ul the calyx, depressed conical, deepl}- grooved toward the margin. The plates are quite small, scale-like, slightly convex, and of nearly nniform size. Orals indeterminable, but there are along the line of the and)ulacrn. over each rny. three plates .*onicwhat larger than the other.'!, which may represent riulial dome plates of a first and second order. Anal tube almost central, small for the genus.

J/nriiii)) (iii(f J.(i(iiJi/i/. — Lower Burlington limestone; Burlington, Iowa.

l}/jic in the Illinoi.s State Colled ion at Springfield.

Jtiiii'ifls. — This species, which represents a transition toward 7'ch'io- criii'i.i, is readily distinguished by the depressed form of the disk, and the scale-like plates of which it is compo.scd.

Actinocrinus trijugis (S. A. >rii.i.EiO.

ISStl. lilitl,:,-,-!,iiit /,iir',/i.':—K A. Maiiri; Adv. Sliwls 17lli Kcj). G™1. Sm-v. Iiulmim, p. fiO.riate 11, fi-s 1, i. :i.

A smtdl species of the t^-pe of A. /cJiulscHfjitut!. Cal^x wider than high, distinctly lobed between the arm bases. Dorsal cup low cnp-.^haped, about twice as wide as high, the sides rapidly spreading and convex. Surface of plates covert'd with angular radiating ridges, which meet in a small node at the centre of the plates ; there being one ridge to each side except from the antero-lateral radials and anal plate, whence two ridges pass to tiie ba.sal.s. Tlio ridges parsing up the radiaN and brachials somewhat the strongest.

Basals small, forming an almost flat hexagonal di.sk. which is bnt little larger than the column, and has a small, jientangular axial canal. Badials large, n-arly as long as wide. First cost.-ils qnadrangular. twice as wide n» hmg ; the secon( a little larger and pentangular. Distichals moderately

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ACTIXOCUIXID,!:.

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large and axillary. Of the paliuar.s only one plate is prL'scrvcd, and so tlio number of arms eannot bo accurately ascertained from the specimen ; but to judge from the size of the arm openings^ i' ij quite probable that it had an additional bifurcation, and the species had six arms to the ray, but not eight as suggested by Miller. Arm facets directed horizontally. Regular intcr- brachials : 1, 2, 2 ; the first very large, rising to the top of the second cos- tals ; those of the third range meeting the intera;iibulacrals. Aniil plate smaller than the radials, followed by 2, 2, and 2 pl'ites. "N'eutral disk con- vex, composed of but Sew plates. The ambulacrals, which are represented by three large pieces over eacli ray, are spinous; while the orals are almost flat. Anal tube stout at the base, but rapidly increasing in size upwards.

Horizon and Luca/if//. — Chouteau limestone ; near Sedalia, Pettis Co., Mo.

T//2)e in the collection of S. A. Miller.

Actinocrinus arrosus (f. A. 5rn,i,i:i!). riufe L V. Fifjs. 7, and Sa, h, c.

1S92. Ji/uirorriiiiif rirrosiix — S. ,V Millkii; Ailv, Sliccis IStli Kcp. Gcul. Suit. Iiidiann, p- 41, Plalc 7, V'Kt. 1 to 5. Syn. Jlluinrfiiiiis l/nllatiis S. A. ifiLi.E!! ; iliid., p. J-], riiiti' 7, t'igs. 0 and 7.

Of medium size. Cal^-x distinctly quinquelobate, its heiglit equal to three fourths its width in well preserved specimens. Dorsal cup saucer-shiiped, its height less than balf that of the ventral disk ; the surface dei'ply sculptured ; the radial plates being strongly keel-shaped, the intcrradial ones provided with a sharp central node, leaving deep, pit-like depressions between the nodes and the ridges. Suture lines indistinct.

Basal cup small, projecting but little be^-ond the colunm. and only the angles of the plates bending upwards; it is notched at the sutures, and tri- lobate in outline. Eadials a little wider than long, covered with a transverse node. Costals as wide as the radials, but oidy half as long ; the first quad- rangular ; the second pentangular and generally a little larger than the first. Distichals one, small, axillary, supporting apparently a single palmar. Arm openings twenty, arranged in pairs, and directed lioiizon tally or slightly downward. The number of arms unknown. Interriidial .spaces subovate, composed at the regular sides of three plates, of which the two upper arc quite small, and placed level with the arm openings. The anal plate as large as the radials, and similarly sculptured ; it supports two plates in the

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578 TUK CKINOIUEA CA.MKUATA OI' NOIJTU AMKKICA.

liist, unci two ill tlio sccoikI low. Ventral disk liiglily elovatetl iiiul bulging at tliu OLiler iiiaigiiif*, wlit'ie the pliUes sliind uivet. Onils iioilose, piii-lied over to the aiiturior side, and in tlie larger .specimens separated hy aeeessoiy pieces. Kadiiil dome plates as large us the orals, strongly nodose and soinc- tiines sul.)spiiioiis. The interambulacral plates in contact with the iiiter- brachials. Anal tube subceiitral, rather large at the base.

ILirizun ami Locullt;/. — Chouteau limestone ; Sedaliu, Mo.

Ti/pcs in the collection of F. A. Sampson, Sedalia.

Jiiiiitrks. — This species is closely related io Aciinocrinus {Bhirocrhms) (rijiii/is, if not identical with it. Miller claims the latter species has eight aims to the iiiy, and tiie other but four, neither of which is clearly shown by tlie specimens. However, there can be no doubt that Miller's •• Jilidro- cr/'niti '' biil/<(/ic< is identical with this species. We examined a miniber of s[)ecimeiis from the collection of Mr. Sampson, some of which were labeled by Miller U. nn-osu-i, others JJ. hii/kttiis, and found that he had described the pimiiper s[)ecimeiis as JJ. hiiUufns and the crushed ones as B. iiirofus. 'We also became convinced that the anus of this .species is not so cxccntric ns it appears in .Miller's figures, which represent it wlieii puslied out of place by oblique prt'ssure, but that its position is almost central. This is clearly shown by Mr. Sampson's lieautifiil .specimen, of which we give three figures on Plate LV., Figs. 8«, b, c.

STEOANOCRINUS Mki-.k- and Woktiikn-.

Ml'-,. Mki.k mill AV(iiitiii;n; fn'ol. lUp. Illint.U, Vol. IT,, p. 1(15, aUo iMil, Vol. HI., p. 171. 1S7',I. ZiTTKi. (■iiiligciius n( .lr/i/firriiiii.<); Iliindb. d. riilii'iiiit.. Vol. I., |i .'(7(1.

I'-Sl. \V. niui Si', i H.'viaioii I'iik'ocr., I'ait II., p. lH)(l'i nl. M-m\. -Nal. Sii. I'liila., p. 321!).

l55'J. S. .\. Mii.i.Kit; X. .\ini'r. fifol. unci I'iiliroal., p. -2SJ

Svii. Jc/iiwrriiiut ; Sin MAtin, 1S:)5: TIai.1., I'^liO; .Mkkk Mini AVohtiikn, ISfiO.

Ill its li'eiieral structure reseiiiblin<f ArtiiKirr'nDin, but the rays, instead of being produced into mere lobes, are formed into arm-like, tubular extensions or trunk.s, which rise to the full length of the crown, giving off armlets alter- nately from opposite sides. There are either one or two of these brachial trunks to the ray. according to species, depending on whether they take their origin from the co^tals or distichals ; they were apparently rigid, and movable, if at all, only as a whole. The dorsal side of those appendages is foriiicd by a longitudinal row of axillaries. or by a succession of syz^'gie.s, in which latter case the second plate of the various orders is arm-Iiearing.

T

ACTINOCIUNMIKE.

570

They are closed vcntrnlly by two rows of small, irregiiliir side-piocos, which rest upon the intlocted edges of the hnichiids, and enclose a single row of rather large, cuneate, spinous covering pieces, alternately arranged. The upper angle of the brachials is irregular in position, the side bearini"- the iirin considerably shorter and distinctly sloping, the other one, supporting the next brachial, horizontal. The arms are given oil' at the sides, the proximal joint resting upon the axillary below, and against the truncated lower face of the plate above ; they are much smaller than the truid<s, blsoriid, and pinnule-bearing. In all other points the genus resembles Avtinocrhiiis.

DiMrihuthin, — Known only from America, and here only from the Kin- derhook group and Bm-lington limestone.

Type of the genus : Slcjuwicnum jtciitaijoinis.

Steganocrinus pentagonus (iTAr.i). P/ide LXI. Fiijs. oil to e ; und 4", ^•

IS.'iS. Aflionrnuiis peiitiigoiiiix — IIai.i. : Gc»!. Hn]). Innn, Vol. I,, Part U., p. 577, Pinto 10, Fif;s. (lajj.

l"i(iti. Sleijiiii'irriiiiis i)eiitiiijii,iiis — .\1kkk ami \V(iiitiii:n ; (Icnl. l{i'|i, Illinois, Vol. II,, p. KMi.

181)8. SliydiifH-riiiii.i i)nitiiii<jii'(x — Mekk anil WomiiKS- ; ihid , Vol. 111., p. 174, Plate ICi, l"ig. 8.

1S81. Slfy'iiiijeriiiiix luniliigoiiiis — \V. and Si'. ; Revision I'alir kt , I'avl II., p. l.'il.

Calyx of medium size, wider than high, distinctly pentangidar in its dor -al and ventral aspect. Dorsal cup nearl}- twice as high as the tegmen, its sides slightly convex to the top of the first costals, the second costals and distichals bent abruptly outward, the latter to a horizontal position, forming five calycine extensions, which bifurcate from the second costals into two free trunk-', which bear arms alternately from each side. Plates of the cup thin and but very little convex; their surfaces marked by radiatintr ridsrcs. which meet in the centre of the plates, where they form small nodes. The ridges are in single series, except between the radials and basals, where there are two.

Ba.sals rather small, forming a short, rapidly spreading cup without pro- jecting marginal rim ; the suture lines slightly grooved. Riidials and first costals proportionally large, al)ont as long as wide, the latter a little the smaller, and their .sides inflected at the upper end to receive the second costals, which are small and distinctly rounded on the back. Distichals 2X2, connected laterally, about half the size of the upper costals, and twice as wide as long, each giving off an arm laterally, one from the one side, the

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680

THE CRIXOIDEA CAJIERATA OF NORTH AJIICRICA.

Other from tlio opposite. Tlio socoiitl disticlials are cunciite, so that tlio sloping iip[ier faces of both together serve as an axilhiry, from whicli are given off tiie free iiriii tninlis. Each succeeding order of brachials in these branches consists of a single plate, which in form and size resembles the arm-bearing distichaN, and each one is irregrlarly axillary, supporting npou its shorter sloping side an arm, upon the longer upper side a brachial of a higher order. The exact numb(;r of successive bifurcations cannot be ascertained, but there were not less than forty from each a]ipendage in full grown specimens. The upper and lower faces of the brachials are parallel, their dorsal or outer surfaces somewhat convex or transversely angular. The trunks arc nearly three times as thick as the arms, and taper but slightly. Their iinier cavity, which is oval in outline, is roofed over vcntrall}' by two series of side pieces, which enclose a row of large, distinctly cuncate cover- ing plates, alternately arranged, and extended into long, upright siiiiies. The apposed faces of the lower brachials, from the costals np, have a perfo- rate transverse ridge, and the facets of the proximal arm joints also are per- forated, but have in place of a ridge a concave surface. From the I'igid ventral structure of these appendages, it seems impossible that there could have l)ceu any moliility between the brachials, but there wiis evidently some sort of articulation at the l)ase of the arms. Arms \i:\y short and of equal length. They are given off at almost right angh.'s, are biserial. somewhat flattened, and evei'y arm joint on either side is produced laterally into a prominent spine. At the side of each arm. close to the base, there is a small respiratory pore. First interbrachials larger than the (irst costals, followed by four plates, which are placed on a level with the arm trunks, the two outer ones, which are somewhat smaller, being in part intcrambulacral ; they bend outward, and hell) to U)vn\ the trunks. The anal jdate is smaller than the radials. and supports two plates in the first row auil live in the second, the latter arranged like the corresponding plates of the regular i.ides. Tegmcn depressed, sur- mounted by a moderately large anal tube, rising abrupth- from the sunnnit ; the [ilates arc large, almost ilat. ami either perfectly smooth, cr crowned by a small central tubercle. Orals in lateral contact : the posterior one nnusu- ally small and lunate, its place being largely taken up by the tube. The aml)ulacral plates elevated, alternately arranged in two rows; the axillary plate spinous. The plates of the anal tube strongl}' nodo.se.

ILinr.on ami LofaJif//. — Lower Burlington limestone; Burlington, Iowa, Sedalia, Mo., and Lake Valley, New Mexico.

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ACTINOCRINin.E.

081

Type, in the (Wortlien) Illinois State collection, Springfield.

Ranarks. — In the specimens from New Mexico, the entire surface of the calyx is covered with numerous irregular pustules, which are not represented in specimens from the eastern localities.

V m

Steganocrinus araneolus ^Ikeic and Wokthen. Piute LXI. Fhj>i. 2a, h.

ISnO. Ai-Hnocriiim araiieutiis — ^t. iiiiil AV. ; I'locccd. Aciul. Nut. Sci. riiiln., p. 387.

ISIiO. Sliyiiiwci-iiiiis ii/-ii/iru/ii.i — M. and \V.; Gvii\. Hep. Illinois, Vol. 11., p. 1(1'., I'late 15, Figs, lu, b,

18S1. Sfrijtiniii'i-iiius iii'tnifulits — W, and Si'.; Kcvisioti I'ahi'ocr., I'art II., [i. 1j1.

This form in its general .structure agrees so closel}- with the preceding one, that the question arises whether it is not a mere variety of that .«pecies, or perhaps its young stage. But the differences, such as they are, are .so constant among a large number of specimens, that it has been deemed safer to treat it as a full species. It is not necessary, however, to give a repeti- tion of the general structure, but it will suflice to point out the special characters in which the two forms differ.

Calyx from one half to one fourth the average size of S. juiitdz/ojnis!. and proportionally more depre.s-ed, its width to thr top of the first costals eqiud to once and a half its height. Tlie ])lates of *hc dorsal cup more tumid, and the ridges more prominent ; those of the tegmen more evenly nodo.-e. The basals are shorter, and almost invisible from a side view. It has but one row of distichals instead of two, and only the plate at one side of the rny is nrm- Iioaring. There are, as in the other species, two brachial trunks from each ray, which stand out horizontally from the calyx, both arm-bearing, and each one giving off from twelve to fifteen armlets. The palmars of both rny divisions support an arm at the inner side of the rny. the jiost-pnlmars at the outer, and so on from nlternate sides. As a rule, each successive oider consists of a single plate, but there are occasionally syzygies, at which the arms are given off from the second plate, a fiict which has never been observed in the other species. The arms are short, and their joint.s are not alternatel}- spinous, but have serrated edges. In all other points this .species agrees with the preceding.

Horhnn ami Loralifi/. — Same as last.

Ti/jye in the (Worthen) Illinois State collection at Springfield.

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TIIK CUINOIDKA CAMKUATA OK XOUTII AJIKUR'A.

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Steganocrinus oonciunua (Siumauu). r/atc LXI. Figs, rja, b.

lS.').'i. J,-l!iiofriiiiis coiifiiiiiiix — SillM. ; (ii'iil. Siirv. MisM.iiri l)v S«all(i\v, Part II., ji. ISO, I'liilc ./, Y\\i. 5, IMiii. .I'Hiiurriiiii.i fuiii'iiiiiH! — MtfiK mill WciUTiiKs ; (iciil. \\i\\ llliiinis, VdI, 11., \\. -.'UO, I'hili' 15,

Y\^*. S)a, ti. ISSl. SIfjiiiiui-i-iiiiif ruih-iiiiiii.t — '\V. i\iiil Sr. ; Uivisinii rMlicncr. , l';irl II , p. l,"il.

Svii. Aiiiiiocriiiiis viiliilux — Mkkk iiiul WdliriiKS ; ISiiO, I'l-cicToil. Aeiul. N:il. Sci. I'liilii., ji. ;!9 !■.

AiioIIkt si)ecius closely reliiteil to S. jimtni/oiina, but larger, the plates more robust and of difl'erent proportious, the (ir.st costals couiparatively suialler, the second much shorter and smaller generally, the basal cup deeper. Calyx nearly as high as wide, convex at the sides, distinctly lobed at tlio top of the first costals, the intorradial spaces between the brachial truidxs extremely wide and depressed, the marginal part of the ventral disk con- stricted, the middle to the base of the anal tube almost flat. Dorsal cup decidedly convex, thick and heavy in the middle portions, thinning out toward the margins. The edges of the jjlates marked by low, louuded ridges, which either in single series oi' in groups of two or four traverse the sutiM'e lines, and procci'd to the margins of iidjoining jilates, leaving the greater part of the plates perfectly smooth. The ridges are not only surface elevations, but originate in part from a folding of the plates themselves; they extend only to the centre of the first costals and second interbrachials, not to the upper portions of these plates, nor to any of the plates above.

Basals large, forming a spreading cup, with well defined suture lines, and shu'iily angular lower margins. Radials about as wide as high, considerably larger 'h.in both costals together. First costals generally about half the si/e of the radials, hexangular. the sides inflected at the upper end, the upper lateral faces longer than the lower, the upper faces narrow, semicircular, concave, and perforated. Second costals hexangular, very short, curved like arm plates, their upper angles obtuse. The higher brachials are not pre- served in the specimens, but the general structiuv indicates that the}- formed two trunks from each ray with an oval cavity. First interbrachial as largo as, or larger than, the first costals, followed by four plates, which are about level with the appendages; the two outer ones a little the smaller, bending outward, and in part intcrambulacral. Anal plate smaller than the radials, supporting two plates in the first, and five in the second range. Ventral di.sk very .slightly elevated, the plates convex, the anal tube somewhat excen-

liit'.

T

ACTINOCUIXID.K.

683

trie. Tlic anibiiliicni roofed by two rows of large covering pieces, wliich are more regularly arranged in young specimens (Fig. ">/;), in which the inter- iiinbidacrals are less niinicrous. The same is the case with the orals, which in the smaller specimens are in contact, hut separated by perisomic plates in larger ones.

ll'irir.im (Uid Locitlihj. — (^nly found in the n|)per part of tin- lT|)])cr Bur- lington limestone; IJurlii'^ton and Pleasant tirove, Iowa, and jMariou Co., Mo.

T^l>e. in the (Worthen) Illinois State collection at Spriiigdeld.

Itciiiiirkx. — Snecimens of this and the two prece<ling sjjccies are most commonly found with the axillary costals and all succeeding plates Ijrokeii off, which might give the impression, to a person judging by such a specimen alone, that the caly.x contained only one plate above the radials.

I

■«■

Steganocrinus sculptus (IIali.). riutc LXI. Fiff-s. lu tuf.

\KA. A,-tiiini-riiiii» .mil/ilin — U.i.u.; Gool. Utp. lown, Vol. I., I'liit II , f. 58J, Pinto ]n, Fifjs. 11«, i.

I'll;!).

h'fjitmi

■iiiKx xnil/iliis — MKKKiiml WdliTliKN; (icdl. Hep. llliiioi-, Vul. 11, |i. 197.

1811. SIfi/iiiiiiciiniin sciilpliix — W. and f^r. ; Kiivisiim riilicocr., I'iiit 11, p. 151.

Calyx rather large, biturbinate, somewliat higher than wide, the dor.sal cup but little higher than the ventral disk, its sides convex to the top of the costals. The higher brachials bend obliquely outward, and their sides up- ward, so as to form with the ambulacral plates above five long tubular appendages, one to each ray, from which the arms are given off alternately from every second plate at opposite sides. Plates thin, highly ornamented with series of well delined angular ridges passing from ]ilatc to plate. From the middle of tin; radials and anal [jlate, throe to five of these ridges proceed to the basals, three to the first costals, and 1, 2, or 3 to adjacent radials and first interbrachials ; while there \n generally but one ridge between the other plates, of which that between the costals is decidedly' the heavier and rounded on the back.

IJasals moderately largo, forming n spreading cup, Avith .slightly angular lower margin ; the intcrbasal sutures distinct but not grooved ; axial canal large, and apparently circuliir. Uadials about as wide as long. First costals nearly one half smaller than the radials, slightly wider than long, and hex- angular. The second costals much smaller than the first, and irregularly axillary ; one of their upper faces short and distinctly sloping, the other

,1' L'l

%

584

TIIK CUINOIDKA CAMKKATA OK XOHTII AMI'.KH A.

/ B ;

')

almost hori/.ontal ; the foriiicr Nupportiiig an Mini, wliicli is freo from tlio secoiul plute, tlie latter two disticliala. The sut'ceecliiig arniH arc given oil' in exactly tlie same nianiier as tlie (irst ; every second bracliial is axillary and snpporls on its nhoi'ler sloping side an arm, and on the opposite side two brachials of a higher order, until finally mar the tips of the arms the last axillary gives origin to two arms. In large specimens tiiere are not less than fifty orders of In-achials to each ray — a very young spe<'imen before us has but fifteen, and a somewliat larger one twenty-two — and these form straight, arm-like, apparently inlh'xible trunks, which at the proximal ends are four or live times as heavy as the ormlets. The plates of w hieh they are composed arc short, three or four times as wide as long, with crennlated apposed faces, the armlets resting against Ijoth plates. The inner cavity of the appendages is qnite large, suboval in outline, the longer diameter directed dorsally and ventrall}', and the tubes themselves taper but little upward. Their ventral side is roofed by a simple row ol large, spinous cov- ering ])ieces, somewhat wedge-snaped and alternately arranged, together witli small, triangular side-pieces, which are united with the brachials and covering plates by close suture. First interbrachial as large as the first costals, the two plates of the second range but very little smaller, those above much smaller and irregularly arranged, varying in the third row from three to five, and in the fourM; from five to seven, the latter meeting the tegminal plates. Tegmen hiyh, contracted in the lower part, then rii-ing almost vertically, and rounded near the summit ; it is composed throughout of small, spinous pieces, sharply pointed at the upper end, and so irregular in their arrangement that neither the orals nor any of the other disk plates can be identified. At one side of each trunk, and alwa^'s opposite the first arm, within the tegmen, there is a large respiratory pore; and smaller ones occur along the appendages aside of every orm. Anal tube rather small au<l nearly central. Column of moderate size, the joints so short that at 30 mm. from the calyx it contains sixtj- joints with fifteen internodes. The nodal joints very little wider than the intervening ones.

Ilorhon ami LocaVilij. — Lower Burlington limestone ; Burlington, Iowa, and Lake ViiUej', New Mexico.

Tiipc in the collection of Prof. Worthcn.

Bemarla. — This species differs from all others in having but five brachial trunks in place of ten, and in having the lower brachials much more deeply incorporated into the dorsal cup.

4-

ui (•

[? '■

ACTIXOf'HIXin.'E.

586

I |?l

^ r»

SteganOOrinUB globOSUS W. und Sr. (nov. spec). Plate LXI. F'uj. 6.

Cnlyx almost perfectly globose ; the distlchals a little projecting so as to give to the section a very slightly pentangular outline; the interspaces be- tween the rays wide, but not di'pnsscd as usual in this genus ; the plates nearly flat, and apparently without ornamentation.

Basals small, disk-like, and following the general curvature of the calyx. Radials and costals slightly decreasing in size upward, all one third wider than liigh ; the first costals hexangular ; the second generally heptangnlar. Of the disticlmls only one row is preserved, but its plates not being axillary they were followed by another row horizontally disposed, as their facets are directed outward. There are two openings above, whicli apparently represent the inner cavity of the two ambulacral appendages ; they are large and close together. Regular interbrachials : 1, 2, 2, 3, followed by the plates of the tegmen. Anal side much wider, the anal plate, which is as large as the radials, supporting 2, 3, C, and 6 or 7 jilatcs above. Ventral disk hemi- spherical, as high as the dorsal cup ; composed of numerous almost flat pieces of nearly uniform size ; the ambulacral pieces arranged in two rows, which branch on the disk. Anal tube somewhat excentric and rather small.

Ilnrixon and LocaUtij. — Oolitic bed of the Kinderhook group ; Burling- ton, Iowa.

Tijpc in the collection of Wachsmuth and Springer.

Ihiiiftr/rs. — The unique specimen from which this species is described is not sufliciently perfect to indicate positively its generic relations. It agrees, however, in all essential characters with Stcf/anocrimis, and we regard it as an early, not fully developed form of that genus.

74

11

!'

lO

\\l

oSO TlIK CRIXOIDKA CAMKRATA OK XOUTIl A.MKHICA.

AMPHORACRINUS Aisriv.

I'^lS. ArsTIV; Qihiil. .tniini. (I.i.l, S.ip., T.niiilcMi. V..I, IV., p. 20i.

ISjS. HiiKMKiii l,flliH':i (iioj.'ii(i!iti('ii (Aiisit. II). |i' '■211' (ill pill'' .IH'irifoeriiiHi).

ISfll. IIm.i.; lli.>tuii .liiiini. N'lil. Ili-I,, |p. iMI (in imil .l,/<iri.-iu-,-iNiia).

ISWl. Ml tK iiikI WiiliTHKS ; (ii'iil. Ilcp Illinois, Vol. 11, p v'lm (ill |ii\rl r)uri/rriiiiif),

1879. ZiTTKi,; llnnilli. il. I'lilii'niil., Viil. I, p. ;(7il (siiliiic'iiiis dl' .lrfiii„rriim<).

1S^1. W. iiMil Sr. ; lliii^idii I'lilivorr., I'miI II , p. Lll (I'runiil. Ami. Nul. Sci. I'liilii., p. .125).

1S8U. H. A. Mii.i.Kii •, N. Anicr. (inil, nuil I'lilii'unI,, p. 2J:).

B.m. .Iiii/i/mrii ('I'Mliiiii.AMi ; Isill, l(<'li(pi. C'lnncrv., p. 30.

Svii. .Ir/iiineriiim I'liiLMis, WM); I'oriluik, IsHtj .Mcdy, ISHi mid Ilnll, ISOO (Siippl. Ocol. lirp. IiiHii).

Tlio riiy.>< of tlio ciilyx, like tlioio of J .tiiiiirriuun, oxtciuled oiitwnnl, nnd foriniiif,' fivo lobi's, wliicli arc distinctly .-lepiiratt'd hy the plates of the iiiter- I'dilial are.Ls. In Anijilnirarriiiiis, how .ver, the dorsal cup is nhoiter, either Hat or sMUCor-slmpod; the proximal part of the brachial lobes projects downward, hidiiij; the whole or a ])art of the cup from a side view. The ventral disk also is proportionally mucli higher, and provided with an cxcentric, very short anal tulie, while the tube of Actliiorrinii.i is nearly central and very long. In the known species there nrc never any radiating ridges npon the plates, the entire snrflice of the calyx presenting a rather uniform, granular appear- ance, peculiar to this genus, which is diflicult to describe. Basals three, short, disk-like. The rays free from the top of the second costals or first distichals, whence they extend outward and downward. Arms heavy and biscrial, either branching or simple; in the latter case provided with lateral spines, given ofT at intervals from opposite sides. Anal plate generally smaller than the radi- als, and followed either by two or three plates, of which the middle one, when present, is cuneatc, and wedged in between the other two, often barely touching the anal. The second row of interbrachials stands on a level with the brachial lobes, and the plates arc in part interambulacral. Orals large, and always more or less spinous. Ambulacra apparently cov- ered by perisomic plates to the base of the free rays. Cohinni round, of moderate size, and with a small, pcntangnlar or five-rayed canal.

D'sMhiiiidti. — Restricted in America, so far as known, to the Waverly group and Low^r Burlin>*tnn limestone ; in Europe it occurs in the Carbon- iferous limestones of Crcat Britain. Only three species are recognized by us in America, and a like number is recorded from Europe.

licmnrJcs. — Cumberland, in 1S2C, proposed the name Amphora for two .species, which he distinguished as No. 1 and No. 2. The former, and the

i

ACTINOCIUXID.r,.

687

only ono to which his (IcHcription niiplicH, Ih nn Artinorrimis. TIic other wn« iimdo hy Austin in 1S48 tlio typo o[ Aiiij)/i>ir(irriiiiin, nuA Ix now known lis Aiiij)li<inwn'iiitn GUbcrlnuni (Miller) = Aiiiiincrtiiii.i (Unji/iciit I'ortloik. nnd MiliifiliiiiH iiiii/ihoni Goldfu.HS.

lioeuiLT iinil Hull confounded ^l/»^^/i'/;v((V7//»,'( with /l//'(/vV(((/'//((^'<, nnd Meek iind Worthen nt first with JJi>r//rn'iiii>i, bnt afterwords accepted the genus in its present I'orin. It did'ers from hoth generii essentially in the arm Mtrue- ture, as well as in the form and pof^ition of the anus; and they have also uniformly a second anal plate.

Aiii/i/iwarri'iiiis appears to bo a soniowhat ahcrrant form, and has (|uile frequently three plates ahove the anal piece. This, however, is found only among the American species, and only in ^1. ilinri/tns and ^1. rlnilnnh'.* ; Anqtliiirwriiiiis Kjiiiiu/'far/iintiin and the three Kuglish species always having the usual two plates. This might seem to indicate that the two former are generically distinct, and shoidd bo removed to tho BatocrinidiV, if it were not for the fact that they also have occasionally but two plates ahove the anal, an<l that in their arn? structure, as well as in other resjjects, tlii'y agree most closely — even more than yl. .'>y(///f>/^/«t7</((^/« — with the typical Ibrin from England, of which we have a most excellent specimen with arms, from Waterl'ord, Ireland. To understand the case correctly, it is important to note that the middle plate over the anal, when it does occur, is compara- tively small and cuneatc, often barely touching the anal plate ; and we think it not improbable that it really represents n plate of the second row, and is not a true homologue of tho middle jdate in the Batocrinidie. On the other hand, we must remember that Aiii/ih'iniciiuus is one of the earliest represen- tatives of the .\ctinocrinid;e ; and it may be possible that it is a transition form, in which the Actinocrinoid structure has not been as yet persistently established, At any rate, we see no good reason for sejiorating the two forms, even subgenerically.

Worthen, in the Geol. Rep. of Illinois (Vol. VIII., p. 8C, Pinto 11, Fig. 8), described a specimen under the name of Am/i/ionwriinis Jernff/ciisls, which is interesting as having bnt four arm-bearing rnys, the free pnrts of the nntorior ray I'vidciilly having been destroyed during the life of the animal, nnd the break closed l)y abnormal growth. The specimen is too imperfect for a cor- rect diagnosis, and we think it highly probable that it is nn Atjurkocrbms.

! I

1

I

in

M

688

THK ClUNOIDKA CAMKUATA OF MUM II A.MKUICA.

. )

i:i

\

1 i

:r

* I

AmphoraorinuB divergena (IIali.). lUdte LXll. Fiju. ~t, (111, h, T'l, b, .S'</, l>, r, !), 10,

I'flO. JrliiiDi-rhH' (lirrriifiit — ll»l.l, ; 8u|i|il. (iinl. Uip. Iiiwn, |i, Itfl. Ihil. .//.(/Muc.o'ciuKi r//iv'(;y.-«< — W. nnil ^<^. ; llid^lMii I'iilu'orr,, I'lirl II., p. ISS.

1SU3, Jiii/it(inii'riii(a liivrytiii — WliJTHtl.li i Mini. Aiiitr. Miiii. Niil. Hist. N. York, Vol. I., p. S], Pint*

i, FIk«. lit, 13.

Sjrii. .l,'fiiio<'r/iint /i/iiiiii/Mti/i.i IIai.i. 1 8ii|i|il, fiiMil, Hep. Iiiwn, |i 10, ll((iirril in Sinio Mm. Nnt.

Iliit., Hull. I., I'liilr I, l''i({i. lit mill W — Jitiiiliurdcriiiin iiliinuliinilh M. iiiiil W. ((ii(pl. Ili'p.

llliiiuU, Viil. v., p. 3'('*).

Byn. .I'liHocfiiitit i/Hm/ii'iiiHHt WiiiTr, isnj, PnioiTil. Ilcntnii Snc. N,it. III«t., Vol. IX., p. 15

^ Jmiihorinriiiin yXtf/Aii/ii'/iKj W. mid .M. j 1S(.'I, (Iciil. Hep. Illinnlii, Vol. V., p. I18S. Sjrii. Jm/iionicri/iiis i/iiiryw, viir. uinlliniiiiuaiia hlttK iiiiil WimtiiKN, (iiol, Itcp. lllliiuin, Vol, V., p. 3SS.

Of ratlicr largo wizo. Crown in its niUunil roiidition, willi nil (lio nrinn preserved, as wide as, or wider than, liigh; the dor.sil eiip not vif<ihle from a side view. Calyx subpyraniidal, dintinctly lobed above tiio firHt contain, tiio intcrradial Hpaecs deeply depre.Msed between the free rays. Dorsal cup about one third the height of the ventral di.-<k. Haiirer-shapud, truncated at the bane. The rays from tiie seeond co.stals droop downward to the level of the bottom of the cnly.v, and then, at about the top of the fir.'^t pahnars, they bend nb. ruptly upward, and I'old inward until the tip.s of the arni.s encircle the spi- niferous summit of the di>k, e.xpo.ting the spines. The entire surface of the caly.K is covered with irregular granules or vermicular nuirkings.

Basals forming a slightly projecting, liexagonal disk, extending beyond the sides of the column ; the suture lines distinct, but not actually grooved ; axial canal small ami sharply pentangular. Radials all hexagonal, owing to the straightness of the lower margins, and about once and a iialf as wide as long. First costals almost horizontal ; wider than the radinls and nearly as long; strongly inllectetl at the sides, and rounded exteriorl}- ; the upper face .semicircular in outline, ami directed slightly downward. The succeeding brachials constitute a part of the free extensions, and face more or less downward. The second costals, which are a little smaller than the first, are touched by the interbrachials only at their lower ends, the lateral upper parts of the plates resting against rigid ambulacral plates. Dis- tichals various in number, but as a rule the two posterior rays have one plate in each division, both axillary, and about as large as the second cos- tals. They support at each side a large quadrangular palmar, which is fol- lowed by a smaller cuneate one, and this by two rows of extremely short

^^'V

I

W

■ ^1

A('TiN()('niNir),i:.

C80

\

nriii [iIiitoA. Otil^' tilt' ni'.-*t imliiiiii.i aru in loiitaut lutiMiilly. tin' otiiors ]imti^ fi'ou. Ill tlio tlii't'U uiiti'i'ior \nyn only oiio of llio tli'^liclml.s \h uxilliiry; tlio opiioHitu one, lu'ing tiiiiicnlftl, (tiiiiiioits two or tliict^ inoio iiioiieriiti'l)' liirj^o ciinoiit'' tli.><tii'lialH, which aru fuliowt'ii hy the n'giiiai' aiTii platt'H, Soiiio- tiiiii'M, hut I'xcfplioiially, liolii (iif(tii'hal>* iiiv tiuiioato, and thu ray Iiiim liiit two piiiiiaiy arms, wiiilo tliL- oilier rays have thive or lour. The lirsl hiniicii- iiig of tliu arum giMiurally taki>- piiicu from thu ninth to tiiilh lioiihlc row <it' joints, the hocoihI and liiiiil ''loin thu ti'iith to (iftuontli ahovu. The hifiirca- tioiiM arc kIvcii oIT at one .side of tlio iiiaiii ami, whioli gcnurally has tliri-o bifurcations, somuliiiu's, howovor, hut two ; the}' aro widely divi'ijrt'iit, and the sidi'-hranchcH rarely hifiircutu again. Anns heavy throughout, tapering very little upward ; at each hifureation there is a fiinall node, and the arms themselvos are slightly inllalud — a peculiarity liy which they nre readily recogni/ed. Pinnules apparently small, their two or three prosimal joints provided with small hoid<s. Anal plate ('on>ideiiil)ly nitrrower than the radi- als. Iiiterhrachials in two ranges ; there heing one and five at the regular sides, and three or two followed hy five or six at the anal side. When then' are three plates in the first row, the iniddh; one is narrow and wedged in between the two at the sides, often barely toiichiiig the anal piece. The two outer plates of the second row at each side of the area curve outward in the direction of the free rays, and nre largely iiiterainliulacral, touching hut slightly the costals; the extended up|ier part resting again.'<t the covering plates of the ambulacra. Ventral disk from the top of the free ray.i to the base of the orals oheonical, leaning a little to the anterior side ; broadly coni- , eal above; the plates irregularly arranged, slightly convex, about efpial in size. The orals occupy the truncateil upper face of the di.*k ; the posterior one i.s located in the centre between the orals at one side and the anal tube at the other; it is strongly nodose or subspinou.s ; the other four orals are produced into long, very heavy spine.s, which either gradually taper to their extremities, or widen upward and fork at the top. Anal tube very short and stout, directed obliquely upward ; the opening lateral, and fiiirrounded by four or five acute spines of fully one half the length of those surniounting the orals. Ambulacra hidden by superimposed phitc to the bases of the free rays, where those of the first and second order are represented by a single, strongly nodose plate. Column moderately strong, the nodal joints consid- erably widest, and angular at their margins ; while the intervening ones are very short.

V*

t

> f I

m

590

THE CUINOIDKA CAMKHATA OF NOKTII AMKUICA.

Horizon and Locality. — Lower Builiiigton limcstouu ; Burliiiy ton, Iowa, and Luke Valley, New Mexico.

T1//1C m the (Worthen) Illinois State collection, Sj' ingficld.

Jt'cni'o-ks. — With the excellent material before uis, we have attempted in vain to .separate from this fiwcica Acttnucriiiius jjlunokixi/ia Hall, Ac/inucriniis fjiiiitlrixpiitK-i White, and Aiiij'hnrncruitis dinri/ciis, var. miil/lrumosiis M. and W. We admit that in tiome of the specimens the radials and costals are com- paratively shorter, the number and branching of the arms slightly dllTerent, and the snrface onuunentation somewhat coarser or almost obsolete ; but these characters appear to be 'ndejiendent of each other. Nor can the fork- ing of the oral spines, upon which Meek and Worthen proposed a variety-, be considered a valid distinction, because it occurs as well in the smaller speci- mens of the type of -^1. (jiiodrinj'intts, as in the typical form of Anqihunidiaus dircri/cns.

' ' /

I ^

Amphoraorinus viminalis (Hall). r/afe LIV. Fhj. S.

1803, .Ic/imeriiiHn viiiiiiinli' — 'Wu.L; ]7tli Hop. X. Y. Sliilc Ciil). Nnt. Hist., p. 54, mid 1S75, Gcol. Surv.

Oliin, Palii'oiil.. VmI. II , p. K;:., riiitc II., KiKs. 12 to U. ISSl. Aiiijihurucriiius riiiiiiialis — W. iiiiil Si', j lii'vision I'ala'ocr., I'liil II., p. 155.

Below medium size. In the form of the dor.«al cup. style of ornamenta- tion, as well as the general structure and mode of branching of the arms, resembling the preceding species. Dor.sal cup depre.'fsed turbinate, the sldcS rapidly and uniformly spreading from the truncated base to the top of the costals, above which the brachials form free lobes, which droop to about the first bifurcation of the arms, leaving only the basals and radials visible from a side view. Plates almost flat, cxcejit for the general curvature, but owing to the rather deep grooves at the sutures they have the appearance of being slightly convex ; their surface obscurely granulated.

Basals forming a very short, subhexangular cup, which slightly projects over the sides of the colimm ; the interba.sal sutures distinct but not grooved. Radials two thirds as long as wide, and as large as, or larger than, botii cos- tals together; the lower .''loping sides much longer than the corresponding upper ones. First costals (luadraugular, three times as wide as long; the second smaller than the first, broadly triangular in outline ; they are followed by 2X2 short, quadrangular dislichals, which are connected laterally by

•fs

1

»■ '^w

i '■ li'l

i; li I

ACTIXOCRINin.i:.

591

suture, and support the free ariris. Tliere are but two primary arms to each ray, wliich branch tliroo or four times at irregular intervals, the first bifurca- tion takinj^- place above tiie fifth to sixteentli double row of ossicles, the last a short distance from the tips. Arms divergent, rather stout, and tapering very little; they arc cylindrical, and above the second plate biscrial, the two proximal ones of the primary arms being euneate. First interbrachials of moderate size, rising to the height of the second costals ; the two plates of the second row are to a large extent iiiterambulacral, touching the distichals but sliglitly at their lower ends. Anal plate a little longer than the radials, and nearly as wide ; followed by three plates, of which the two outer ones are as large as the single plate of the regular sides, the midi ,o one smaller and cuneato. The togmen is not shown in any of the specimens, being cov- ered by the arms, but apparently it had no spines, or the points would bo visible at the ends of the arms.

Horizon and Locali/i/. — Waverly group; Richfield, Summit Co., Ohio.

Tt/j)cs in the New York State Cabinet at Albany, N. Y.

Amphoracrinus spinobrachlatus (TIall.). I'/ate LXII. Flfi><. ], 2, 3, 4.

ISOO. Arliiiocriinis spiiiohriu'liiuliix — IIai.i. ; Sujiiil. Gcul. 1!i p. Iowa, p. fi.

1873. AiHiilini-iii-riiiii-i (^i) .yiiiihlii-iuiiidfiis — Meek ami WoiniiEX; (icol. Rop. Tlliiiois, Vol. V., p. 3S!t,

IMiilc ('), Til's. 5rt, h, c. 1881. Auqiliin-iicrinHH sjiiiinlji-iiiliiiilm " AV. iiiiil Si". ; licvUiiiii Piilirocr., P.irt 11., p. 155. Syii. Arliiiiin-iiiii.i iiij\iiliix IIai.i, ; ISfin, Sn|ipl. flodl. Hep. l<i\vn, p. 20.

S_vri. jMphunirrhiKS iiijliiliis — WiiiTnEi.D; Mem. Anicr. Miis. Nat. Hist. N. York, Vol, I., p. '2-3, I'lalc i, l''i!,'s. 10, 11 (not .lr/iiiiifi-iiiii.i {.tmiilioruenniix) iiijlutiin Hall, ISOl, Bosloii Soc, Nat. Hist., p. 'i^-V ^fsx A;fii fif'ocriiHta iiijlafnii).

Calyx subpyramidal, di.stinctly lobed ; the dorsal cup shallow-saucer- shaped ; almost flat, and in .specimens with the arms preserved not visible from a side view. Ventral (H.-^k nearly as high as its width at the arm bases, inlliited above the food grooves, and the lower part of the interambulacral spaces depressed. The plates of the dorsal cup thin, their surface covered with irregular, rather prominent rugosities, which are confluent, arranged in rows, and form transverse ridges. The ridges upon the radials are crescent shaped ; those of the first costals straight, while those of the second costals and distichals are angular, their salient angles directed upward,-*, the ridges upon the interbrachials le.ss distinct, and longitudinally arranged.

Basals forming a hexagonal, slightly projecting di.sk, which extends but

li

'ti

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502

THE CRIXOIDKA CAMERATA OF NOKTII AMERICA.

I I

I i

Hi

little beyond the sides of the column ; colunni facet concave. Radinls once and a half as wide us long, the sides rapidly spreading. First costals fidiy as wide as the radials, but considerably shorter, subquadrangular in outline, but generally hexangular. Second costals a little longer than the first, and directed slightly downward, as also the distiehals. Distichals nearly as large as the second costals, and all axillary, supporting upon each side two moder- ately large pahnars, which are laterally connected and support the free arms, of which there are four to the ray. Arms simple, long, heavy, rounded in the lower portions, llnttened and wider in the upper; the tips incurving. Tiie two proximal arm plates cunoate, the two rows of ossicles succeeding them moderately long, and every sixth one extended into a sharp lateral spine. The spines increase in length upwards, commencing as small nodes, and attaining at the upper part of the arms a length of 2 or 3 nnn., the cor- responding ones placed opposite. First interbrachial comparatively small, higher than wide, followed by two rather large plates in the second row, and one or two smaller interambnlacral pieces at each side. Anal plate remark- ably small, only half a-* wide as the radials, supporting two plates, which arc followed by three large and two snuiller ones at the sides, the latter bending outward, heljiing to form the free rays. Plates of the ventral disk slightly convex, their surface covered with small pustides without definite arrange- ment. Orals a little larger tiian the other plates, and formed into short spines ; the posterior one placed at the side of the anal tube. Anal tube cxcentric and very short, directed obliquely upward. No ambulacral plates are visible to the base of the free rays, where those of the first and second order are represented by single plates. Column composed of rather long joints ; the nodal ones considerably widest and rounded along the margin ; the axial canal small and pentagonal.

Horizon and LocaH/i/. — Lower Burlington limestone; Burlington, Iowa, and Lake Valley, New Mexico.

linivirJcs. — This .species is readily distinguished from all others by its arm structure.

Tijpc in the (Worthen) Illinois State collection at Springfield.

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I

ACTINOCRINIU.E.

593

PHTSETOCRINUS ^r. and W.

1809. Meek and Woutiien (Subgenus of Slrotocriiiu.i) ; Proceed. Acad. Nut. Sci. Phila., p. 15S ; also 1873,

Geol. Ui^p. Illinois, Viil. V., (i. 349. 1831. W. and Sr. ; Kevl.sion Palifcii'i-., I'ari II., p. 155 (Proceed. Acad. Nat. Scl. Plilla., p. 329). 1SS9. S. A. MaLiiU ; North Anicr. Gecil. and Palajonl., p. ilVJ.

Arrangement of the plates up to the distichals as in Act'inocrhmn ; but the anus located within the teginen, not at the end of a tube. The calyx dis- tinctly lobed. The arms arranged in groups*, and given off from tiie two main divisions of the rays alternately from opposite sides. Hut, contrary to the case "n Actinocrinus, each order of brachials, from the costals up, consists of but a single plate, which is axillary, and supports on one side an arm and upon the other a brachial of a higher order. Anns biscrial. Interbrachials numerou.s, and in contact with the plates of the disk. Ventral disk depressed at the summit, plicated around the margin, and generally composed of small, irregular pieces. Anus excentric. Column round.

Distribution. — Only known from the Burlington group in America, but i( apparently occurs also in the Mountain limestone of Ireland. 2)ipc of the genus : PJnjsctocriniis vailricosKS.

Hcmnrks. — Zittel makes Phi/setocriuns .synonymous with Slroiocrimis, and the latter a subgenus of Aciinocrinus.

Physetocrinus ventricosus (Hali.). Plate LXIII. Fig. 0, and Plate LXJV. Fi</s. 1, 2, 3, 4, 5, G, 7, and 8a, b.

1853. Jr/iiiorriiiiis ven/rifosiis — II.iLI. i fleol. Uep. lona, Vol. I., Part 11., p. 595, Plato 11, I'igs. Cxi, h. 1873. Phiiseluerinm rfnirifosiis — Meek and WoKTIlEX*; fiuol. Kc|i. Illinois, Vol. V., p. 319. 1881. PhijfPlonimisvnilrinfux — Vi . nnd Sp. ; Kevisiiin Pnlirocr., Part II., p. 157.

Syn. AcHiiorriiiiix nilji-fiilrii'nsiis .Mi CnK-sxEV ; ISIil), New Pal. Foss, p. 21 also 1809, Chicago Acad. Sci., Vol. I., p. 16, Plate 4, Fig. (i.

Syn. P/ij/fflorriiiiif siihreii/rieosKs — Mkk.k and WnnTiirx; Geol. Rep. Illinois, Vol. V., p. 319.

Syn. Ai'tiiiocrinui ventrirosiis var, taiiri'Ualint, It.tl.I.; 1''01, Prelim. Deser. Pal. Foss., p. 3,

Syn. Ai'linocrinm vrnlnonsiis, var. iiitfrnmliux IIai.i. ; ISOl Host. Jonni, Nat. Hist., p. 273.

Syn. AiHiioirinun venfricosiif, var. retieuliifii.i ]I.\i.i, ; ibid., p. 279.

Of more than medium size. Calyx generally as wide as high, somewhat higher in young specimens. Dorsal cup basin-shnped ; the sides convex below, more rapidly spreading from the top of the distichtils; the arm bases pro- jecting, deeply grooved between the rays and their main divisions, and slightly between the individual arms. Ventral disk hemispherical, varying

75

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I i

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594

rilc; CRIXOIDKA CAMKRATA OK NORTH AMKRIC'A.

|i '

li

I'loiii onu third tlie lii'ight of the calyx in hirge spechnens to scarcely one foiiitli in snmller ones. Plates of tiie cup convex and of rather unit'orin size ; tiieir surface ornamentation exceedingly variable. In most specimens, the middle part is bare of all markings, but along the margins of the plates there are at each side from one to three elongate piocesses or short ridges, and between them along the suture lines deep pits, which almost penetrate the test. In other specimens there are continuous ridges covering the whole surface, which give to the plates a reticulate or cancellate appearance ; while in still otiicrs rows of bead-like elevations take the place of the ridges.

Basals forming a low, cylindrical cup, which is somewhat grooved at the sutures. Radials and costals of nearly the same size, and all as long as wide ; the first costal a little smaller and hexangular, the second heptangular. Distichals 1 X 10, al>oiit half the size of the axillary costals, and all axillar}' ; the higher orders of brachials much smaller, and rounded like arm plates; the bifurcation being alternately from every s\icccssive plate. There are generally two or more orders above the palmars, sometimes three, and in young specimens occa- sionally but one ; the number of arms, therefore, varies from four to six in the main branches, and from eight to twelve in the ray. Arms given off alter- nately from opposite sides, and the proximal one free above the second plate, the others above the first; tliey are below medium size, long, and rounded on the back. Pinnules covered with small hooks. Regular interbrachials from eight to ten, in six or seven ranges. Anal plate as large as the radials; followed by 2, 3, 3. .'], 4 and two plates. Interdistichals two or three. Inter- brachials as well as the interdistichals in contact with the ])lates of the di.^k. ^'entraI disk deeply jilicatcd around the margin; the plates simill. generally smooth, and of iieaily the same size and form. Column of ncail}- uniform size to about li cin. from the distal. end, where it gives olT strong branches at irrcgiilar intervals, and tapers gradually to a sharp jioint. The nodal joint -i MIC a little the longest and widest near the calyx, but become indetcr- miiial)le farther down ; axial canal of moderate size.

JIun'zoH ami LoraJiti/. — Upper and Lower Burlington limestone ; Burling- ton. Iowa, and at several localities in Missouri.

7}//>i- in the | Worlhcn) Illinois State collection, Springfield.

Jtoinirks. — This species has been divided up into several varieties, ba.sed upon certain variations in the ornamentation of the plates, which cannot be recognized in large collections ; and McCliesney described a young specimen as a new species. As a rule, in the smaller specimens the tegmen is more

'«("-

actinocrinip-t;.

595

(kpressed, nnd the dorsal cup more elongate proiiortionalh-. This is also the case with the specimens from the Lower Hurliiigton bed, the calyx being one fourth liighor than wide, and the specimens have but six arms to tlie ray, but are in other respects identical with those from the Upper bed.

Physetocrinus dilatatus (Ji. ana w.). Plate LXIV. Figs. 9, 10.

1S09. Slrotocrimis (P/iyse/oniiiiis) (lilalaliis—yiv.v.v. and Wohthks ; Trncecd. Acad. Nat. Sci. Tliila.,

p. \i\i. Also 1873, (icol. I(c|). IlliiKiis, Vol. V., ii. Srili, I'liiti^ 10, Fij,'. 0. ISSl. P/ij/.vfucnim dilalnlas — W. nnd Sp. ; Revision I'nlicocr., I'lirt II., p. 157.

Calyx moderately large, the cup saucer-.shaped, rapidly expanding from the basals to the top of the distichals, and more rapidly liience to the free arms, which at their ba.ses are directed almost vertically, and owing to their large size are much crowded. Plates of the dorsal cup slightly convex, with shallow indentations at the angles of the plates.

Basals short, not chickened or expanded below; axial canal large. Radials and costals nearly of imiform size, a very little wider than long. Di.^tichals almost as large as the costal.s, and of similar form; they support an arm, which is free beyond the second plate, and a palmar, which cither su])portH two arms, or a single arm and an axillary post-palmar. The arms thus vary from six to eight to the ray ; they are very stout, increasing in thiek- nes.s from their bases up imtil their size is almost doubled at about two inches from the calyx. Regular intorbrachials : 1, 2, 2, 2, 2, 1. Anal plate a little .shorter than the radials; followed by 2, 3, 3, 4 and two plates. In- terdistichals two to three. Ventral disk low-liemisphorical, slightly plicated around the margin ; the plates small, irregularly arranged, and of about the same size. Anus excentric, at the top of a small protuberance.

Horizon and LocaUly. — Upper Burlington limestone ; Burlington, Iowa.

Type in the Museum of Comparative Zoology.

Ecmarks. — This .species is readily distinguished by the flatness of its calyx and its stout arms.

I

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596

THE CRINOIDEA CAMERATA OF NORTH AMERICA.

I i ' '

FhysetoorinuB asper (M. and AV.). Plate LXIII. Figs. 7a, h.

ISflO. Sliotoeriiiii.'(P/iyif/orriiius) mjier — Mkek niul AVouTiiEXi Proceed. Acail. Nat. Sci. Pliila., p. ISlj

iilsu Geul. Kep, Illinois, Vul. V., p. 351, I'liile 7, Ki>;s. lit, 6. ISSl. Phi/selocriiiua ii>iicr — W. iiiul Si', j Ucrisiuu I'ulreocr., I'lirt 11., p. 157.

Calyx moderately Inrgc, liiglior than witle. Dorsnl cup obconical, with nearly straight sides, gradually expanding to the top of the di.stichals, the higher brachials curving obliquely outwards. Ventral disk highly elevated, hemispherical, occupying fully one third the height of the calyx. Plates of the cup convex, covered with one or more rather large, angular protuber- ances of inegulai form and size, some of them round, others elongate, and some transversely ai;\ingcd, others longitudinally.

Basal cup broad, nearly three times as wide as long, not thickened at the lower margin, deeply notched at the sutures, and presenting a trilobate out- line from a dorsal aspect. Eadials wider than long, and as large as the two costals together, which are of nearly equal size, and almost twice as wide as long. Arms ten to the ray, five from each subdivision ; all free above the axillaries. Anal plate narrower than the radials, supporting ten or eleven plates in five rows. The regular interbrachials consist of about eight pieces, which connect with the plates of the disk. Ventral di.sk inflated ; composed of irregular, ilat pieces of moderate size. Anus subcentral, at the top of a small protuberance. Column small, round, the four or five proximal joints subeciual.

JIurizon and Localily. — Upper Burlington limestone; Burlington, Iowa.

Type in the Museum of Comparative Zoology.

Iiciiiarks. — This species diflers from all others of the genus in the form of the calyx, and its style of ornamentation.

Mw

ACTINOCRINID^.

697

Pbysetocrinus ornatus (YIall). Pla/e LXIII. Fiys. 1, 2, 3, 4.

1S58. Ac/lnocrimii ornnfiia — l\\u,, GccjI. Itrp. lonn, Vul, I., I'lirt II., |i. BS3, Plntc 10, Fig. 12. Ib^y. I'lii/.ielucriniis oniatm — Mkkk nuJ Wohtjien; Guul. Kip, Illinois, Vul. V., j). 3iUj iiUu W, and Hp., 18S1, Hcvisioii I'liliTOcr., I'arl II., p. 157. Svn. Arlimcriiiu.i semirim Hall; ISfil), Suppl. Gcol. Itcp. lown, p. 25.

Svii. Aetiiiorriiiii.i /Iri/hi — S. A. MiLLtu ; 1S92, Adv. Sheets IStli Hep. Ceol. Surv. Iiidimin, p. 30, I'liilc (1, I'igs. 1-i.

Calyx of incJium size, depros.sed bowl-slmped to tlio top of the costnl.f, thonce spreading abruptly to the arm bases; the di.stichals and palmar.s lon- gitudinally rounded and laterally inflected fo as to form at the arm regions, between the rays and their sulnlivisions as well, deep grooves, whioli give to the cal^'x, as seen from above or below, a distinctly lobed outline. A'cntral disk but very slightly convex. Plates exceedingly thin and delicate, beauti- fully ornamented with angular, well defined ridges, passing from plate to plate and meeting at their centres ; tlio.se running up and down the radials and braeiiials tiie strongest, and dividing the surface of the dorsal cup into five nearly equal fields.

Basals very small, represented by a short dentate rim. which slightly projects beyond the column. Eadials wider than long. First co.stals hex- agonal; the second equal to, or larger than the first. Distichals somewhat smaller, the interspaces deeply depressed and occupied by one or two small interdisticli. ■;. , giving off an arm from one side, which is free from above its first plate, and a palmar from the other. The latter supports the second arm and a post-palmar, which in turn gives origin to two arms, there being four arms in each main division, and eight to each ra}'. Arms moderately tiiin, somewhat flattened in their upper portions. Pinnules composed of very long joints, bearing a small hook near the outer end. Fegular interbrachials: 1, 2, 2, 2 ; tho.se of the second range almost as large a^i that of the first row, the two upper ones minute and on a level with the ai'in bases. Anal plate a little smaller than the radials, supporting 2. .", 3, 2 plates. Interbrach- ials at all five sides in contact with the plates of the tegmen, as arc also the intordistichals. Ventral disk deeply grooved near the arm bases, which gives to the surface a plicated aspect ; it is composed of very .small pieces, which are flat and quite irregular at the middle of the disk, but near the outer margins, where the small covering pieces of the ambulacra are exposed.

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608

THE CRINOIDKA CAMERATA OF NORTH AMERICA,

their arrangement is regular, and tlio plates nodose. Orals eainiot be recog- nized. Amis excentric, slightly raised above the general nirface of the disk ; the opening direeted ( iteriorly, although occujjying the posterior side of the disk. Column composed of rather sliort joints, the nodi'ls a little the widest; axial canal moderately small.

lloi-hon and Localili/. — Lower Burlington limestone ; Burlington, lown, and Sedalia, Mo.

Htmarlis. — Actinocriniis sciiarius was described from a specimen of this species in which the last bifurcation in the calyx is broken away, and which was supposed to have but six arms to the ray.

IBtii

|V '

FhysetocrinuB Copei (R. A. Milleh). riale LXIIl. Fi(j. 5.

1S91. Aelhiocriiim Copei — S. A. Mii.Ltu; Juiini. Ciiiciii. Sue. Xiit. Hist., Vol. IV. (Dccbr. iimiibci),

I'liite 7, Fi^s. 2«, b, e. 1SS5. Plii/fflucriiiiis Cupei — W. niul Sp.; Revision Pnlrcocr. I'liii III., p. 113.

Nearest to PJii/sdocrhius onm/iis, but with fewer and larger plates, and the calyx proportionally higher ; height and width as seven to eight. Sides of the dorsal cup evenly spreading from the foot of the basals to the top of the costals, and thence more rapidly to the arm bases, where the interspaces between the rays are deeply depressed. Ventral disk hemispherical, occupy- ing about one third the height of the entire calyx. Plates of the dor.sal cup a little convex, covered with well defined ridges, meeting in the centre of the plates and running to adjoining ones. There are three ridges between the radials and basals, and two from one radial to another, which together form concentric triangles. The ridges between the other plates are single, l)ut within the corners of their triangles there are angular nodes, which are sometimes connected and also form triangles.

Basals short, their lower margins somewhat projecting outward and crenulated at the edges ; interbasal suture lines .slightly grooved. Radials as long as wide. Costals nearly as wide as the radials, but one third shorter; the first hexagonal, the .second heptagonal. Distichals and palmars smaller in proportion, both angular on the back ; the latter supporting the arms, of which there are four to the rny. Arm facets large. Regular intcrbrachials : 1, 2, 2, 2, very gradually decreasing in size. Anal plate usually a little smaller than the radials ; followed by 2, 3, 3 and 3 plates. Intordistichals one, elongate. Ventral disk plicated around the margin ; the surface of the

i

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i

ACTiNOcnixin-T;.

599

pktcs bcrtiitifiiUy grnnulnfod. Iiiterninbiiliicrnl plntos flat. Ornls rrownccl with a siniill central tnliorck', as are alwo tlio plates roolin^f the ainixilMcra, which are Irreyiilarly arranged, and decrease in si/e as they approach the arms.

Horizon and Locallfif. — Lower Burlington limestone j Lake A'allcy, New Mexico.

Ti/j)e in the collection of Prof. Cope.

Fhysetocriaus lobatus W. and Sr. (nov. spec.). rick LXIII. Flip. Sa, b.

Calyx ])roporti'-.iially higher than in the preceding species, height to width as ti"-. lo nine; distinctly lobcd at the arm regions. Dorsal cup sonic- whii*^^ bulging, slightly constricted across the distichals. Ventral disk almost tat ; intcrradial and interdistichal spaces — the latter from near the sununit tf the disk to the second row of interbrachials — dcejdy grooved, giving to the surface of the tcginen, and to the upper part of the cup a sharply lol)ed outline. Ornamentation of the plates siniilar to that of J\ Co/ni ; but the ridges, as a rule, more prominent, the inner faces of the triangles deeper, and all enclosing a second triangle within the outer one.

Basals moderately short, forming a cup with slightly projecting lower margin, and snui'l notches at the sutures ; a.\ial canal small and pentangular. Radials and cost.ds as long as wide, or a little longer; the first costal two thirds the size of the radials and he.vangular, the second somewhat larger than the first, and hoptangular. Distichals and palmars small, both even with th ■ costals, but raised considerably above the intcrradial spaces. The distichals give off an arm to the outer sides of the rays, the palmars two arms, making si.\ to the r.ay. Structure of the arms unknown. Regular interbrachials: L 2, 2, 2 ; the anal plate followed by 2. 3. .3, 2 plates; the nppor row at all sides in contact with the plates of the tegmen. Tlates of the disk almost fiat, small, and of uniform size ; their arrangement irregular, except on approaching the niiii-;, where they become alternate. Orals inde- terminable, and probably wanting. Anal regions slightly bidging, the open- ing directed anteriorly.

ILiri-nn (lUil Localiti). — Lower Burlington limestiue; Lake Valley, New Mexico.

Types in the collection of Wachsmuth and Springer.

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600

TUK CUINOIDKA CAMKUATA OK NOUTH A.MICHK A.

CA.CTOCRINUS W iiiul Sp. (ih.v. gon.). (KanTos n, tlioriiy plant, k^hVov a lily,)

Ciilyx fronornlly lon},'er tliiiii wide, tlio vi'iitiiil dink hij^h, ponicnl, pnssiiij^ },'ra(Iuiilly into a ^^tI■tlllJ;. iilmuxt central tube. Tlic pi iti's of tliu eiip oriia- iiioiittHl hy nuliatiiij; ridj^cH and nodcM. llasaln throe, conipMrativcly nli(irt. Costals two, gem-rally lie.vaguiial and iieidayonai. Dislieliais I X lO, all axillary The Huouocding orders of braeliialK, when present, al.xo eonsist of a fiiiyie row of plates, hut oidy one plate at eaeh side of the ray is axillary ; the other one is truncated, and gives nlT an arm which is free from the sec- ond or third plate; the axillaiy supports either two Himi)le arms, or one from one side nnd two from the other, the arm-* heing given ofT alternately from opposite sides like the pinnules. Arms equidistant or nearly so, long, bisc- rial and int'oMinj; ; hack and sides generally covered with nodes or thorns, nnd the pinnules with shari>ly pointed hooks. The piimules arc in close eon- tact, and those of one side of the arm are placed with their ventral faces flouting those from tiib opposite side. They are compo.scd of numerous elongate joints, which, with the exception of the throe or four distal ones, are produced into sharp, prominent hook-;, directed obliquely upward nnd outward, and arranged in rows parallel to the sides of the arms. The hooks of one pinnide curve over the back of the adjoining one, so as to give to the mass of pinnules, in their dorsal aspect, the appearnnco of a fine network in which their outlines cannot be distinguished. The ventral furrow is cov- ered by two rows of side pieces, which enclose two rows of minute covering ]»Iates. Interl)rachial8 numerous, separated from the interambulacrals by the upper row of fi.xed brachials, which arc in contact laterally. The plates of the ventral disk are morn or le-^s spinous, and so irregular in their ariango- meut that it is often difTicidt to identify the orals and radial dome jjlates. Anal tube very long and almost central. Column large ; the axial canal pentangular.

T,'//ic of the gcnns : Curfnrriniis f>ro/iosc!(htl!s (Hall).

l)lstriliidii>n. — Restricted in America to the age of the Kinderliook group and Lower Burlington limestone, with n single aberrant survivor in the Upper Rurlington beds. The genus may possibly bo represented in Enro]ic in the Mountain limestone of Ireland ; but, so far as we know, not in Bid- glum, nor in the Yorkshire Leds of f]ngland.

ACTIXOCBINID.K.

UUl

liiiiiiirls. — The viuioiiH npooion wliioli we refer to flim genus were, with n sini.'lu exception, originally dencrihed uwiU'V A'/iitmi aiii.i ; init Meclv and Wortiicn, na we have already «tated, jtlaced them in a wection \>y theninelve«. The arniH of these HpccieH iiro given olT in a ('(inliniiouM row aiound the eidyx jiroper, and the liil'ureation i« on .Mueees.sive hrnehials hcyoiid the distichals; wiiile in Artiii'irfliiiin the calyx in more or less distinctly loljid, the arms aro given ofl' in clusters, with largo plates interposed between the rny», and the bifurcation is on every Hucond or third hrachial. The structure of the pin- nules also is essentially dilTerent in the two groups.

Ill one very frail specimen of Viii'lufi'liins jinilmsfiil'dis^wK' were enidilcil to examine the structure of tiie piiuiules on all sides. Al >ome places on the ventral Hide the covering plates and side pieces were removed, and henciith wa.s exposed the lloor of the food grooves, formed of two row.s of small trans- verse jiieces, alteriuilely arranged, and in a somewhat sloping po.sition. The Btructiu'O is well shown hy Mr. Westergren's excellent (igures on I'lato LV 1 1 1., Figs. 7'^ A, c. ,/.

McChcsney's Ac/iiiocriinis /iiirdiuinis and A. Fudcr! also belong to this genus, but we are unable to identify the species from the descriptioua and figures. The types were lost iu the Chicago lire.

> V'l

CaotocrinuB probosoidalis (nvr.t.). ' riute LVIII. Figs. J, 4, S, (!, 7a, h, c, d.

18,')9. yfi-tiiiofrhiici /ir„f,M-h/„/ii — lUu.; Occl. l!c|i. Imvn, Vn\. I., I'arl II., |i. .')St, ?lMr in, Fi^. U. Ibbl. .tiiiiiurfi,iiit iirohutriildlia — yf . iiiid Si'.; Iti'vi>ii>ii raliiiicr , \'.\ti II., |), 1 (j.

Svii. .l-/i,iw;-iiii(r 'I'KiffniiiriN.i—Uw.i.; IvfiO, Siippl. (inil. I{i|i. loHii, p 2i, nnd Wliilfiild ISO^; Jlcin. .Viii. Mil-. Xiit. Hist. N. Y(Mk, p. 7, I'liili- 1, I'i^s. l-ll.

Bjll. .1. rri-rr/j/iis IIai.u ; bOl, Desor. Kfw Sprr. C'rin., p S ; iiImp lidslnii .Idurn. Niit. Ilisl. p 270.

Svii. A qiiiilfriiiiriHi, vnr. 'jiiiii/'friit IIai.i.; lb'<l, Ucscr. Nfw SjHO. Criii., p. II.

8yii. .1. M,/,/M IIai.i.; ISfil, iliiil , p. II.

Syii. .i./,i,/n„i IIai.i.! IHlll, ilii.l., p. |:l.

Syu. .i. (iol;/,i,iii/i S. A. Mii.i.Ki( ; ISSl, .lourii. Cinciii. Soc. N':il. Tlist , Vul. IV,, VhU- 7, Fi?s. 1, !</.

Calyx sid)ovate, more or less truncate at the base. Ventrnl disk almost as high as the dorsal cup, very gradually passing into the anal tube. Plates of dorsal cup delicate, traversed by a single row of sharp, well defined ridges, running from the edges of the plates to the centre, where they form con- spicuous nodes, which upon the radials and brachials arc transversely elon- gate, but upon the interbrachials are subcircular and angular.

Basal cup short, .slightly spreading, excavated at the bottom ; the inter- basal sutures deeply grooved. Radials larger than the costals, a little wider

■•'•

,i

<;o2

TIIK CUIXOIDKA CAMKUAT.V OF NDUTII AMKUICA.

I

tliiin lonj,'. First (•o>,,ilf( larger tlwin the dccoiul, qimdriiiiguliir or ixMitanjfiiliir j till) Hui'uiid pL'iitangulur or lu'|ilungular. Di'^ticlialrt otu>, axillary, Hi^iporting witliin the calyx two single paliiiarn, followuil by tliu frou arm platen, which from the hucuiiiI piece iiro nrranged in double ruwr*. AriiiH crowded, long and heavy; their upper eiidx rapidly tapering to a line point; the phitin nonie- what tran-iverMely angular, and the suture lines parallel. I'innulen in eloMO contact, cum poHcd of about lil'teen jointn, from two and n half to three tinicM as long as wide ; nil, with the exception of the three upper oiicm, provideil with a prominent, Nharp hook, directed obliquely upward, and arranged longitudinally in roww parallel with the sides of the arms. Regular inter- braeliials : 1, 2, 1 ; large specimens have an additional row of two plates, and the second palmnrs take part in tlio calyx ; the pnhnnra of adjacent rays in contact laterally. The first anal plate Ih followed by three to fivo interbrachials, there being no higher nnals, and the species has no interdis- tichals. Ventral disk conical, composed of rather largo, spinous or nodoso platcH, separated by small, convex pieces. The plates are irregularly nrranged, and the orals and radial dome |)late8 nro with difiiculty recog- nized ; the posterior oral is erect, nn<l forms a part of the anal tube. The tube, which extends considerably beyond the limits of the nrnis, is composed of convex pieces ; it tapers gradually, niid is quite slender nt the upper end. Column strong, composed near the calyx of alternate thick and thin joints with rounded edges ; the former increase in diameter downwards, while the latter grow narrower, gradually become cylindrical, and incrense in number quite rapidly, there being already seven to the internode at 90 mm. from the caly.v.

IIiii-l~on and Loculihj. — One of the chnrnctoristic fossils of the Lower Burlington limestone j Burlington, lowo, Sedalio, Mo., and Lake Valley, New Mexico.

Iiciiiarl\i. — Wo regard ITall's Aclinocrinus qimfeniaritts nnd its variety spill l/cnts, his ^l. cvcrrjitiis, A. tJiemis, and A. lagcnn, as mere variations of this species, dilTering slightly in the matter of ornamentation. They cannot be separated in largo collections, although they may seem to be quite distinct in individual specimens. Our study of the species is based upon over one liundred good specimens.

I

I

ACTINOCUINIIi i;.

CU3

ml

j

Caotoorlnui luoina (UM.t:), Plate L VI. Fiys. S, 0.

\W, J.HitnnlHiii rm-lHit — VitU.l I'rrliin. r)c'«rr. Ni>\r I'aliToz. Crln.,p 11. liii. .l./4ihffiiiin Ih'Iiiii — W. miii tiv. ; l(c'vl«inii riilinici., I'lirl II, |> I U.

B^ii. .MiHoeriHiu fHlmlui Howur ami lltui) Kniitoa Citjr ttoii'ut., Jul; 1S01, p. 101, flnle >,

fik. 10.

A Hinall Npi'cios. Calyx Mtiirhiimto j tlio nidcH fo (lie top of the rontnls vory nliglitly convex, tlio tli,itii'lml.s ooinowlmt fiprcndiiig. I'latcn a very little I'oviited, ontl covcrod witli ol)«curo rndiiitiiij^ riiljreM.

HhmiiIh rjiiito Hiimll, l)arc'ly projoptiiig ovor tlio Kidos of the rolimin ; tlio Biitiiro liiiu8 diHtiiKitly groovod. Radiids mid iiiiiil pliitu wxy little Iniffcr tlmn tlio costulu ; tlio Iiittor twici a.s largo un tlio di.Htiilialx, wliicli ciippoit two nriTJH, nm' ing four to tlio ray, .vitli fiLM|iicntly an luldilionnl nrtn in tiuli of tlio poHtci'«r rays. Ann* dulioate, tliroo fo four times ns long n» the height ot tho dorsal cup, iiiiMcriiil to the fourth or fifth pinto, llaiteiiing in their ujipor portion i, and arnewhat wiiler at midway tlinn at either ex- troinity. Tho iistiolmU = jiparontly .-insist 'f two pieces forming n syzygy, and another syzygy occurs between ■ '<o first and second palninr, the lines of union at both places being ini. '• more obscure than between the other plates. Tho third, fou'''b, nnd ocrnsionallj ho tilth palmar arc long .Tud cuneato, all above in.r.gi! in double ro. , Tho free arm plates are thickenoil at thoir i!p,itr ciges, and the fides di.stipctly eerrnted. Inter- brachial.s at tho regular sides five to six, at tho a'li' .- do nine to ten. Ventral dink nearly as high as tho dorsal cup, the plates very uniformly Bubspinoiis.

ILirhon ami Lncnlit)/. — Lower Burlington limestone ; Burlington, Towa, and Louisiana. Mo.

Ufiwtrks. — Hall described this species with five arms in the two posterior rays. What is supposed to be tho typo specimen in the Museum of Com- parativo Zolilogy, and two others, show four arms in all five rays ; but in others the posterior rays have five. The form is intermediate between C. proh'^idd-i/l.i and C. rc/lcidafiin, dilTering from them in the smaller size of the a^r ; • • .ery probably it is a young stage of the latter, and should be made a synonym.

V

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604

TlIK CRINOIDEA CAMKBATA OF N'OUTII AMERICA.

I

4

i ?

I

I

1861. 18S1.

Cactocrinus thalia (ITall). Plate LYI. Fig. 2, wul Plate L VII. Figs. 12 and 13.

Ai-liiiocriim» llialiii — II iLi, ; Dcsor. Mew Sprc, Criii. (Prelim, nalicc), p. 13.

Aedaoerinm Ihiiliii — \V. iiiiil fr. ; lU'visiim I'alii'ocr., I'nrI II., p. 111).

Svu. A. iii/rfi/iieiis IIai.i. ; ISfil, Deter. New Spec. Criii. (Prelim, imliee), p. 14.

Svii. A. HoJoaus S. A. Millek; Gcol. Surv. Missouri, Hull. No. 4, p. 33, I'lale 5, Fip. 7.

Of the type of C. prohoxciiMis. Dorsal cup obconicnl, nearly ns high ns wide, somewhat constricted below the arm bases. Plates convex, the surface covered with radiating ridges and con.spicuoiis nodes. The ridges, which are rounded and not very strongly marked, passing out from near the centre of the plates to the sides, where they meet the ridges from adjoining plates. Throe of the radials have three parallel ridges running toward the basals; the two others, tlio.se resting both upon a basal and the first anal plate, have onl}' two, one toward each basal. The ridges between all other plates are single. The nodes, which occupy the middle of the plates, are rounded, broad, and heavy, rising abruptly from the general surface ; those upon radials and brachials transversely arranged.

Ba.s.ds moderately largo, forming a spreading cup, provided at the lower end with a thickened collar. Radials as long as wide, distinctly angular at the lower end. Costals of nearly equal size, one third smaller than the radi- als, and both hcxangular. Distichals and pahnars one, about half the size of the costals, the plates of the upper row connected laterally. Arms very long and slender, four to the ray; composed of short, smooth plates. luter- brachials at the regular sides, 1, 2, 2, 1 ; at the anal side 2. 3, 3, 2; the anal plate as largo as the radials. Interdistichals two, longitudinally arranged. Construction of ventral di.«k and form of anus luiknown. Column com- parativel}' small ; axial canal large and pentangular.

If>ri-nn ami Locality. — Lower Burlington limestone; Burlington, Iowa, and Sedalia, Mo.

Pemarks. — This species is most remarkable for the heavy nodes upon the calyx plates. It differs from C. probosridnlis in the larger size and more conical form of the dorsal cup, the greater number of interbrachials, the presence of interdistichals, its long(T and more slender arms, the size of the column, and the greater width of the a.\ial canal.

ACTIXOCRINIU^E.

6U5

"V ^m

Li 131

Cactocrinus reticulatus (TIaLl), J'ktte L VIII. Fhjs. Ja, b.

1861. AcliiwrriiiHf re/iculti/iis — IIai.1,; Utscr. New Spec, of Ciiu. (incliin. iiotici'), p. 2, and ISuvInn

Joiirn. Nat. llUl , p. il)9. ISSl. Arlinoi'riiii.i ri'lifiildlim — \V. niiil Si-. ; Ui'vision I'lilivoor., Part II., p. 145.

Svii. A. l/wiis IIai.i,; 1801, Dcspr. Nl-w Sp. (.'riii. (picliiii. uoticO, p. 11.

S^ii. A. /ucvl/iis Hall; 1801, ibid., p. 15.

Nearly as largo as the preceding .specie."? Calyx sub-ovuto ; the dorsal cup a little higher than the ventral di.-ik, obconical, .spreading iinilbrinly to the top of the distichals, thence abruptly to the arm bases ; the plates con- vex, and ornamented as in C. pro/mcldalk. Basal cup trilobate, short, thick- ened nt the lower margin, and projecting downward over the top of the column ; interbasal sutures deeply grooved. Uadials and costals decreasing in size upwards, the radials nearly twice as large as the second costals. Dis- tichals and palniar.s in single rows, the latter projecting outward. Arni.s four to the ray, except in the two posterior ones, in which the palmars next to the anal side support two post-pahnars, giving to these ray.s five arms, or twenty-two to the species. Arm facets large, subovate. Arms long, heavy, and but very .slightly tailoring; they arc cylindrical in the lower portions, but llatten toward the tips, and are composed of two series of moderately long pieces, united by parallel sutures, and bordered by four longitudinal rows of sharp nodes, two of them occupying the sides, the two others the back. Regular interbrachials : 1, 2, 2, 1 ; the last, which rests between the jial- mars, sometimes unrepresented. Anal plate followed by 2, 3, 2 and 1 plate, the upper one separating the post-palmars. Ventral disk sidj-conical, cov- ered with well defined spines, irregularly arranged, some of them hi- and tri-partite, separated by smaller convex pieces. Anal tube central or nearly so, of moderate size, its length unknown. Column of medium size, composed near the calyx of alternate thick and thin joints, the former with undulating edges ; axial can.al rather large ond pentangular.

Ifirhi'ii (dul Ltindili/. — Lower Burlington limestone; Burlington, Iowa.

Ti/pc in the University Museum at Ann Arbor.

liCinarls. — This species is readily recognized by its arm formula, its heavy and spine-bearing arms, and by the spinous plates of the ventral disk.

Under the name AcHiincrliiiis hnrlliis. Hall redescribed this species without the tegmen, and under A. thous a specimen with the arms attached.

I ' ■

"sL

■ T I. f*

t

m

'r

006

THE CRINOIDEA CAMERATA OF NOUTII AMERICA.

Caotoorinus retioulatus, var. ovatua (Hall). Fktte L VII. Fig. 11.

JSOl. Ac/ino<-ri>iiii oralus — Hall; Dcscrip. New Pnltcoz. Criii., p. 10.

This form scarcely deserves the rank of variety. It differs from C. nli- culdtttn in tiie more rounded form of the dorsal cup, and the less expansion of the arm liases ; in the more depressed form of the ventral disk, its shorter spines, and in the ornamentation of the dorsal cup. The radials and cos- tals are traversed by three parallel ridyos, which pass into the basals, and generally terminate in denticulate nodes at their lower margins ; the ridges i)et\veen the interbrachials of first and second order, and toward radials and costals Ijeing double, all others single.

IIuinuH and Loculiti/. — Same as last.

Cactocrinus dentioulatus w. ami Sp. (nov. spec). FMe L VIL Fii/s. on, b.

Ciilyx of medium size, al)niptly spreading above the distichals ; the sur- face ornamented by radiating ridges and nodes similar to those of C. n/icii- lat a-i ; the arms covered profusely with tooth-like projections.

Hasiils of moderate size, their lower margins projecting beyond the sides of the columii. liadials as large as both costals together, wider than long, and covered with a cons[)icuous transverse node, from which the ridges pass out to all sides, there being three ridges to the basals and costals, and one to each inlerliraehial. First costals hexangidar. smaller than the second, the latter heptangular. Distichals a little smaller than the costals. Palmars short, and narrower than the breailth of the arms; three of each ray trun- cated, giving off simple arms, the fourth axillary and followed by post- palmars. Arms crowiled and their bases bending outward ; normally five to tlie ray; long, very heavy, infolding, and of uniform thickness thionghout, but tlattening toward the extremities. Tlioy are composed from the second joint up of two series of moderately long, convex pieces, which are stu'- mounted by two .^harp elongate nodes. The nodes increase in length up- ward, arranged in longitudinal rows ; two of them running along the sides of the arms, and tlu; others along the middle, on each side of the median suture line, giving to the arms a somewhat angular outline. Pinnules pro-

J

%

il

m

ACTIXOCRIMD.K.

607

•^

viileil with sharp spines from IJ to 2 mm. in loiigtli. Rojrular inti'ibrnchials : 1, 2, 2, iinil 1. Tho first iinal plutc supports 2, 3, imd o plates, iind prol>iihly two more in the up[)ur regions. Of the ventral disk little is known, except tlmt it was covered by spinous plates. Column iireserved only to the extent of a few pieces, which show that the nodal joints near tho calyx have sharp, distinctly crenulated edges, and that the intervening joints are narrow and evenly rounded.

IIurhoH anil Localitij. — Same as hist.

Ti/jics in the collection of Wachsmutli and Springer.

PiiiKir/rs. — Distinguished from C. rffini/ti/nx and allied species by the arm formula, and tho surface structure of the arms.

Cactocrinus opusculus (Hall). ri(i/e L VI. Fhjs. 5a, b.

l^ftO. Arlinorrinm opiitdilim — IIai.i,; Suppl. fic'ol. Rop. Idwii, I'liitf 2, Fig. 0 (without description).

IStU. Ai'tiiioeriiiiis oiinnciiliii — IIai.i.; Huston Jouni. NmI. Hist., Vol. VII., p. •2(it.

ISSl. Ji'/iiwcri/iH.i o/iiurii/iit — W. iiiul Sp. ; licvisioii PhIuvici-., I'iirt II., p. 111.

1893. WiimiKi.D ; Mem. Aiiier. Miis. Nat. Hist. N. York, p. 9, i'i{;s. 0, 7.

In form and ornamentation closely resembling C fhdis, but the .«pecies is smaller, ami difiers essentially in the surftice structure of the arms. Calyx higher than wide, attaining its greatest width at and above tho arm regions; truncated at the base. Tho dorsal cup riuito narrow to the top of the di.s- tiohals, then spreading abruptly, and forming a short rim, .somewhat similar to that of Strufncniiiis, from which the ventral disk rises almost vertically to one third its height. Surface of plates convex, traversed by narrow ridges, which, passing from the centre of the plates, unite at the edges with those of adjoining plates.

Biisals short, thickened at the outer margins, and indented at tho suture lines ; the lower surface deeply oxcaviited ; sin-fiice of the plates covered with coarse wrinkles. Radials ami costals almost twice as wide as long, tho former somewhat the larger. Distichals a little smaller than the costals. Palmars (piito small ; the two inner ones of each ra}^ sujiporting two arms; the two outer but one. Arms thirt\' ; long, incurving, roumled at the base, but almost perfectly flat above, and somewhat witler, the edges knife-like and distinctly serrated. The arm plates are transversely angular, arranged in parallel rows, each plate marked by a sniiiU node placed clo.se to tiie median suture line. Pinnules similar to those of C. dams, but less c]o.seIy

COS

TlIK CKIXOIDKA CAMKUATA OK NOUTII AMKlilC'A.

K

s

pac'kod, tlie joints longer, tlio spines more sleudor, nnil dirocted nioro nuiuly outward. Intorbrachiuls in tlneo rows; at the rej^ular sides 1, 2, 1 ; at tiie nnnl side 2, 3, 2. sonietinies with a small plate wedged in between the pai- niars, but generally the palinars are in contaet laterally all around. Inter- distichal.s 1 or 2, longitudinally arranged, ^'entral disk high, convex ; the Dials and radial dome plates, which are represented by plates of a first, .second, and third order, large and spinous; the interandjulacrals not very numerous, smaller and convex. Anal tube central, large and long, extend- ing beyond the tips nl the arms, and composed of irregidar scale-liUe jilates. C'olunni of medium side; axial canal rather small.

lIiirirMit mid Limdi/i/. — Lower Burlington limestone; Burlington, Iowa.

7///" in the University Museum at Ann Arbor.

JviiiiirLs. — la a very jonng specimen, evidently of this species, the brachials are free from above the distichals; the palmars and post-palmars are mure elongate in proportion, and luiiseriul and cuneate to the third plate, resembling in their outlines the arm plates of certain Poteriocrinida?. The biserial plates al)ove are also proportionally larger than in the older speci- mens, but have already the characteristic ornamentation of this species.

mi-.

f

Cactocrinus limabrachiatus (IIam,). riafc L VJII. Fhjs. 9 ami JOit, h.

ISOl. Afliiinrriiiii' liiiiiilirnrliiiilii.i-~\l\u.\ Dcmt. New Sjicc. I'al. Ciiii., p. 2j nlso Boston Journ. Nat.

Hist, v„i. VII , p. iCis.

l"""!!. .Icfiiiuci'iiiiin liiiKibnichiiitiif — W. mill Si'.; liivisioii V.ila'ocr., Tiirt U., ji. lU.

Calyx bell-shaped, one third higher than wide, the arm ba.ses slightly projecting; the dorsal cup I'ldly once and a half as high as the ventral disk. Surfai'i- ol' ])latos traversed by single series of angular ridges, continued from plate to plate, and meeting at the centres, where they form sharp nodes. Only tiie basals and radials are connected with one nnollier b^- four or live parallel ridge-.

]5a>als riitiier large for the genus, forming a spreading cup ; the sutiue lines not grooved. Radials a little longer than wide, tiieir sloping upper faces small. First cosfals short, (piadrangular, rarely pentangular, the jipper .'ind lower margins convex ; the second a little larger. Distichals and piilmars smaller in proportion. Arms si.x to the ray, given off as in the preceding species, distinctly flattened on the back, the three or four proxi- mal ])lates long and cuneate. Higher np. where the arms become biserial.

I \

1

ACTIXOCRIXID.K.

609

the plates of one series staiul obliriucly to those of tlic opposite one, the outer ends of the plates direeted slightly duwiiwiird. Each plate, cU)se to the upper margin, is marked by a sharp, conspicuous transverse ridge, while the lower parts of the plates are beautifidly corrugated. The transverse ridges, which somewhat reseml)le the tei'th of a fde, suggested the specific name. Pinnules long; the dorsal side of each joint armed with a sharp, curved spine. Regular intorbrachials: 1, 2, 2. Anal plate followed by 2, 2, 2 plates, and th(;.se by two very minute pieces, placed within the arm regions. Intcrdistiolials one, large. Ventral dislv depressed conical, com- posed of comparatively few large plates, the centre of which is produced into a small slender spine. Anal tube moderately large, and almost central.

Horizon and Locali///. — Lower Burlington litncstonc ; Burlington, Town.

T///>e in the University Museum at Aim Arbor.

lianarh. — DilTering from all other Burlington species of this genr.s in the surface markings of the arms. The set of arms figured by Whitfield (Mem. Am. Mus. Nat. Hist. N. York, Plate 1, figs. 8 and 9) as of this species, in our opinion belongs to Actinncrims tciuii.srii//itiit! McChcsney ; they do not show the sharp file-like ridge of each joint, which is so characteristic of this species.

Cactocrinus longus (Mkkk ji.kI Wohtukn). Plate L VII. Ftfj. 8.

1809. .Iclliiocrinus toiiijiis — ^fEF.K mid WnuTiiEX; Pinoocd. Acnd. Nat. Sol. Tliiln., p. lufi.

1873. Actiiiocriiiiis luiijus — Mkek nml \V(iktiien; (icol. Kep. Illinois, Vol. V., ]i. 315, I'liite 8,

Fips. Iff, b. 1881. Aelinueriiiiis loiK/iis — W. ,iuJ Sp. ; Uovisioii ralipocr., I'lirt IT., p. 144.

A largo and elongate species. Calyx to the base of the anal tidje almost once and a half as high as wide. Dor.«al cup somewhat shorter than its width acro.ss the arm Imsos. the sides a little convex. Plates rather thin, very slightly elevated, and in well preserved spooimons ornamented willi very lino, more or less ob.xcure ridges, which in sets of from one to five ])ass from plate to plate. The basals radials. and costals are traversed by five such riilges; five others proceed to adjoining radials and the anal plate, but only throe from the costals and radials to tlie lower intorbrachials. and fmm the costals to the distichals, while all the remaining plates have single riilges. The suture lines, except the basi-radial and intorradial ones, rarely observed.

77

^li'

I

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I

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It

I

CIO

rilK CUINOIDK.V CAMKUATA OF NORTH AMKUICA.

Ilasiil.s foniiiiijf a .shallow cup, tliu sides gmtlually expanding but not tliickened ; tlio upper margins distinctly angular. Hadials large, fully a.s long as wide. Costals one half .^mailer, alnio.st as wide n.s long. Palniars (juite small, the two inner ones of each ray giving oft' two arms, the o\iter ones but one. Arm bases a little projecting, the facets moderately large and concave; arm openings arranged in groups, those of adjoining rays twice as far apart as tlio.se within the ra^'. Respiratory pores slit-like. Structure of the arms unknown. Regular interbrachials : 1, 2, 2, 1, succeeded by a small elongate piece, wedged in between the arm-bearing brachials ; the first as large as the costals, those of the second row e(|ual in size to the distichals. '{'he anal [ilaio, which is as wide at the bottom as near the top, is fiillowed by 2, .'1, 2, and 2 plates, the latter generall)' sui)i>()rting two snudl elongate pieces, which are in contact with the intcrambulacrals. The interdistichal spaces are deepl}- depressed, and occupied by a single flat piece. Ventral disk subconical, gradually passing into the anal tube, which is almost central, and very stout. The disk, as well as the tube, is composed of an immense number of all sorts of plates ; some of them are large and take the form of elongate uoiles or small spines, others are .smaller and have rounded nodes; while the smallest ones, which are intersper.sed profusely between the larger, are simply convex. Orals extremely excentric, small, ami separated by small jilates; the [losterior one, which stands erect and bears a transverse node, takes part in the tube. Radial dome plates sub- spinous, irregularly arranged, and placed at some distance from the arm bases.

//';■/.;■'/« (IikJ Luni/i/i/. — Lower Tlurlington limestone; Burlington, Towa.

T1//1C in the Museum of Comparative Zoology.

1,'iiiiiid-s. — Meek and Worthen's figure in the Illinois Report is some- what misleading; the plates of this species are generally less convex, the suture lines iilmost obsolete, and the radiating ridges upon the plates more distinct than shown in that figure.

fl

i

ACTIXOCRINin.K

Cll

<*»

Cactoorinus ectypus >rKKK and Won. I'hUc JA'l. Fl<j. 10.

18fi9. S/ro/orrinim erly/i«'— \\. nm\ W ; I'rnpocil. Ariul. Niil. Soi. I'liiln., , 59.

lS7;t. Slfulueriiiiis irti/ims — M. ami W. ; (iidl. lii'p. llliii(ii>, Veil. V., p. \\:,\\, I'liilu 7. I'if;. 5.

1>>S1. Jrlimcriiim eil^jiu) — \V. mid Hi', j l{u\Uii>ii I'lilicoc-r., I'ait ll,|i, 1111.

Calyx elongate, subovato ; tlie ventral di.xk one fourth .shorter than the dorsal cup. Plates of tiio cup moderately convex, a lillle angular in the centre, their .surface traver.sed hy radiating costiv, which in .-et.s c three pas.s from the middle to the .>iidcs of the plates, dividing their .surface into numerous triangles, each of which includes another one. but more obscure.

IJasals forming a slightly spreading cup, more than twice as wide as high, and with small nodes at the lower margin, one placed at the termin.a- tion of each of the costte. Kadials about as wide as long, and nearly as large as both costals together. The .secoml costal smaller than the first, and both wider than long. Distiehals half the size of the upper coslals. The outer palmars of each ray sujiport a single arm, the iinicr ones two. Arms three to each main division, or six to the ray; their structure unknown. Anal plate longer than wide, followed by eight to ten plates, of whidi the two nppcr are small, and connected with the interaiid)ulacrals. Kegular interbrachials : 1, '1, 2, 2, 1, the upper one separating the npper brachials of adjoining ray.i. Ventral disk snbconical, .slightly bulging, the summit passing gradually into the anal tube; the i)latcs are rather large, more or less con- vex or tnmid, and of imiforin size. The posterior oral takes part in the anal tube, which is large and nearly central. Column apparently large; the nodal joints deeply dentate at their outer margins.

Ilurhon and Lorulilj/. — Lower Burlington limestone ; Burlington, Towa.

Tijpc in the Museum of Comparative Zoiilogy.

liumarh. — The typical figure by Meek and Worthen is quite inislead- iiig. being made from a crushed and much distorted specimen. In plumj) specimens the calj'X is not depressed, as di-scribed by those authors, nor do the upper rows of brachials curve out horizontally, but lie almost in a straight line with the radiids and costals. The species has no connection with Striiiocrhms, but somewhat approaches Avtiiiocrimii in having the rays separated throughout their full length, but they are not lobed as in that genus.

•t i

612

THE CKINOIDKA CAMKRATA OF NOHTII AMERICA.

il

iP \

ii

CactocrinuB clarus Hall. Plate LVII. Fuj,. 0 md 10, uml I'kle LVIJI. Fiy. 1.

ISCil. Jr/i/iiieri)iii3 rliirm — IIai.i. ; Dcvr. New Spcr. Ciiu. (I'rcliin. iintii-r), p, 2; nlso Boslon Jourii. Nut. llisl., Vnl. VII , |i. Jw 1 N. V. i>iiiir Hull. Nul. lliM. {]>7-2). l%w 3J, Kit's. 24 aud 25. 18S1. A<'/inwriiiin cliirm — \V. ami Si'. ; It('\l9i>iu I'lilu'iit'i' , I'iirl II., |i. \\i. 1S93. WiilTFiEi.i); Mem. Am. Mu». Nut. Hist. N. Vork, Vol. I , p. 8, I'jiito 1, Figs. 4 nml 5,

L.'iijjor tlian niiy of the prccuiliiig 8i)eeie.s. Calyx once nml n linlf n.s wide ii.i liigli. Dorsal cup depi'os.sed .Hubconieal, broadly truncnto at the bn.se, evenly .■<|)ivndiiig to the top of the ccstalsi, and more nbniptly tiienco to the arms. Ventral disk n.s high as the dorsal cup, somewhat expanded above tiie arm ba.so.s, giving to the cnly.\ a top-heavy appearance; the anal tube rising gradually from the summit. Plates of the dorsnl cup heavy, nnd ele- vated into strong nngidar nodes, which are either sniooth or connected with each other l)y short, indistinct ridges, except the palmars nnd jiost-pidmars, which are rounded off toward the sides, nnd separated laterally by deep grooves. Sutvire lines distinctly grooved.

Uasals l)road, rarely thickened at the lower margins, nnd projecting but little lieyoud the column ; interbasal sutures well marked. Kadials about once and a half as large as the costnls, as loh ^ ns wide. First costals con- siderably narrower; either (luadrangular, pentangular or liexangidar, the second often larger than the (irst. Distichals ns wide as the costaN, but shorter. I'almars a little narrower than the distichals, an<l twice as wide ns long, tlii'l'- outer plates supporting n single arm, the inner one two with post-palmars, except in the two antero-lateral rays, in whieh only o\u\ of the palmars is followed by higher brachials. Arm facets large, ei|iiidistant. and diroct(vl horizontally. Arms twent^'-eight, biserial from tlicir origin, heavy, long, anil in close contact ; they bend jit first outw.-ird, tlun gracefully upward, being roinided on the back, nnd showing no sign of flattening or decrense in width to nenr the tips, where they rapidly tnper to a fine point. Arm joints arranged in parallel lines, quite short, and without ornamentation. Pinnules long, fringe-like, composed of twelve to fourteen joints, each one provided with a long, sharply pointed tooth-like projection, directed obtusely upward and outward, which overlaps the corresponding joint of the next pinnule above, their teeth forming raised lines parallel to the .sides of the arms. Piegular interbrachials : 1. 2. 1 ; the three lower one.s

ACTIN()C'HIXII).^K.

CIS

iA

of nearly equal »izo, and n.s largo as tiic first costala. Occasionally then' \h another small elongate jilate between the arm ha.soH, hut more fretjuenlly this is absent, and the palmare lue in contact laterally. Anal interraduis formed of six to seven plates ; the upper one very elongate, resting between the palinars. Interdisticlials one. Ventral disk covered by niimerons small and extremely irregular pieces, which enclose somewhat larger spinous plates, probal)ly representing the oials, and radial dome plates of u lirst, second, and third order. Column large ; axial canal very wide and obtusely pentangular; the joints are long, the third from the calyx wider and longer than the surrounding ones, in some specimens almost twice as wide, and having a knife-like edge.

ITorizDii and Lovulitij. — Lower Burlington limestone ; IJurlington, Iowa.

Tiji>c in the University Museum at Ann Arbor. Mich.

lieinarlcs. — Tliis species is well characterized by the form of the calyx, nnd by the smooth an<l heavy arms without nodes or spines. It was described by Hall as having six arms in each riiy, which is certainly incorrect. We have examined seven specimens, in all of which the antero-lateral rays have but five arms, while the others have six.

CactocrinuB obosus Kk.vis (Ms.).

Phllc L V. Fl;/s. Ihl, b.

A large species of the typo of C. rlKras, but more elongate, nnich more nodose, and having i)ut four arms to the ray. Calyx once and a half as wide as high, broailly iind sharply truncated at the base; the plates thick and lieavy. Dorsal cup gradually expanding to the top of the distiehals, then bonding abrujjtly outward. The plates of the dorsal cup extremely heavy, highly (dovated, and produced into rather sharp, round nodes, esjreeially ti.e radials, which are decidedly more prominei.c than the succeeding plates; the suture lines traversed by shoit, obscure ridges. Ventral disk high-conical, ns high as the dorsal cup, it-; sides but very slightly convex ; orals and first radial dome plates wedge-shapeil, and produced into very long. shar|i, bidadly trnnsverse tid)ercles. which stanil out conspicuously (;"> to 7 nun.) fiom the tegmen.

l?asal cup short but wide, much wiiler th.'in the column; sidj-cylindrical ; the lower end abruptly truncated, forming a sharply angular edge at the bottom; the suture lines not groined. l{adi:ils a little wider than long.

'^a

) ^J

^

V

if.

Gil

TIIK (lUNlUDK.V CA.MKHATA OK XOlfTIl AMKIUC'A.

I J

unco iind ii halt' iin Iiiigo as llie CirM i-o.^tal.'* ; llu- m'OoihI o<i>'taln n littlo sinalliT tliaii llie I'lrM, holli nearly a.-* lonj; as wiile ; tlio t'diinor la-xanjinlai', tlie latti'i- gfiu rally |iL'iitan;j;iilai'. Di-^tii'lials iitarly ax lai'i^e nn \\u> cti^tal axillary, luit tliu nodi-s ^IkhIim'. PalniaiM two in tlie calyx, sliurt, roiindol, anil both wcdj^f-.sliaiKMl. tlic narrower ends diiccled to the inner side of the ray. Ann t'aeets very larj;e ; the aiuhiilacral pa-if^ajre ohlon^' ; the respii'alory pores proportionally f-niall. Struetnru of arms not known, lint, to jiid^'o from llu' >ize of the faeet(<, ax large as those of ('. ilnriis. Anal side not observed, being t'ovi'red by matrix. I'lates of the ventral di>l< greatly vary- ing; gradually increasing in si/.e and jirominence upwards, those neaiesi iho arm bases being the smallot ami least conspiciions. Posterior oral very large, erect, and furming a part (>!' the liii.-c of the anal t\d)e. its wedge- sbapiMl prominences directed transversely outward. The four other orals a little smaller, and se|)arated from each other, and from the posterior one, by small liat pieces. Anal tube extremely large. .Hubcentral ; composed at the base of \ery large and smaller pieces, the larger ones produced Into wedge-shaped nodes, similar to those of the orals, but somewluit smaller, tlio others having a perfectly Hat -urface.

Jl'iri.iiiii iii((l I.'hkIH'/. — I,ower Hinlington limestone. Ilannibnl, ISIi.ssonri.

Ti/jiis in the .Missouri ."survey collection, and that of Wachsinuth and .Springer.

CactocriDus thotis Hmi. riak LVJ. Fi.jx. ,i an.l 4.

'[^Ci\. ArliiiorriiiiK th'li< — ll\i.i. ; l)rscr. Ni'W Spec ('rill (I'ri'liin, iiiilici'). |v II. WXi. Wiuthh 11; .Mini. Am. .Mus. .Nnl lli,i N. Y., V..1 I , y. fi, rint.' 1, lii:. 10.

Smi. .lrH,iui-i-iiiii< wiinn 11m. T.; I)i".cr. \i\v S|iir. C'liii (IVrliin. imlici ). |i It.

This spi'cies is remarkable for the uniformity of its plates, which decrease but littlo upward. It is of the type of C. i/nrns, but smaller, the plates less robust, and it has six arms to each ray in jdace of live in the nntero-lateral ray.s. It also approaches ('. hjihsch/iis in the calyx, but that difVer.s in liiiving llatteneil and highly ornamented arms. Dor.sal cup nearly once and a half us wide as high, broadly truncate at the bnsc. uniformly spreading to tho top of the tlistichals. and thence idirujitly to the arms. Plates slightly convex, covereil with line, obscure ridges, with or without central nodes.

IJa.sals short, their lower margins cremdated. sligii'ly projecting beyond the sides of the col lunn; the suture lines distinct but not notched. Radiala

■Nbi

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1

^1

•f: f

ACTI.NorillNID.K.

fll5

mill coMtnlx of ncurly tlio naim> n't/.v, and all a littlu wider than lun)r ; tliu (li^ticliids (if lliL' ><!inn' rorin. mid Imt slij.'litly -iimllir; tlie piiliiiiirH alKtiit liidf tlif xi/ii of till' dislicliul-. 'I'lio iiiil'C jmliiiin.-' ui I'acli \ny ^^lllHlOl■l .in arm, tlio inner oiu's fwit small |i(ist-iialiimrs and two arnif*. Alius crowded, long, rather heavy tiii(in>.'li()iit, ronndi'd on the hack, their ni>|ier iiarts ineurving, tiieir |)ro\iiiial eiiils henilin^ aliiui'l hoii/ontallv oiilwiird. liiterlnacliiidM live at tlie re;:ular Hides; 1, '2, 2; and ihriv me 'J, '■>, iiid - aliove tlie anal phite. Some MpeeiinenM liave an athlitioiial narrow piece wedged in between the iialinars. Inleidistichais one N'liilial dink conical, uli^diliy expanding near the arm hascs. then lisiii;.' evenly, and paf.«iiij; insciisiMy into the anal tube, 'i'lie plates close to the arm legioM.s are very .small anil Mimost Hat, iiiglier lip larger and nodose plates are interposed lietween sinallt r ones, and at the t'liot III' the anal tnhe all ilii' plates are huge and sliarply nodose. An.'il tnlie long, extending lieyonil the arms; composed ol' rather largo, convex jiieees, which decrease in size with the tube. Jlorizun and hicali///. — Same as la.Mt.

CaotocrinuH soxarmatus mfmlV

y '/,//<■ /J'. %v jihiwi /

ISOO. Arl!,iwrliiii» Sfxafniiilui— II Ml.; S»\\\A. (irul. Urp. Iiiwii, |i. i\ (iihI linll. I., fi. Y. Sliilc Miis.

Nil. Hist ,!'<;;'. I'hli' :!./, Kiu'. i(i r,„'/. ■ .».. ^j-/,-;/.«.. W amlSr.). ISSl. ./.7i//v.-/'i««.< .«./'i//'»w/«< — W. :.uil Si'.; Ilivisiciii I'liju'cirr., riiil II., p. 115.

Rpiidily distinguished from the other species of this genus hy the form of the calyx, which is liituihinate ; the arm bases are not spreading, and the nrin openings directed oblirpiely uinvards. Dorsal cup deejily bowl-shaped. trunc;ite at the base, the sides slightly convex below, and straight above. I'Lites but little I'levated. their miildle portions Hat and perfectly smooth ; but they are connected with adjiiiiiing pieces by short, prominent ridges, which Ibiiii deep, trigonal pits at the angles (>!' the plates.

Hiisiils tiiloliate. sliort tint wide, and somewhat spreading outward; the lower surlace a little exciiv;ileil for the reception of the column, which occu- pies about half its diameter. Fladiiils very large, nearly as long as wide, nnd nearly as birge as lioth costals together. First costals hexagonal, one fourth wider than long; the second about the same size as the first, but heptagoiial. Dislich:ils. pidmars. and posf-pjilmars rapidly decreasing in wi/.e upward, the first post-palmars elongate and semi-free. Arms six to the ray. the outer palmars of the r.ays being axillary. The structure of the amis is

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616

niK { UIX(»II)K,V ( AMKKMA OF NOHTII AMKIIKA.

not kiiusvn, but tlicy iiiiifl liavo liucii ([iiito ili'Iioiiti'. Hog ii(i' i ;i 't>ncl;'nlH;

1.

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K> ii|i|i('i' otii! iiiii'i'ow mill I'lilcnng tlu'

tlio (ll

\-.l .ll,

III

InU'itlis.

iianowor limn tlio iiuliiil.t ; I'ollowi'il \>y li, ;i, .'!, "J, luul li jii ticlml.i ono. Vuntml disk litMnij<i)la'iic to low-ionictil ; tlu' luiiil tiilie uu')- contml, niotlemtely huiuII, rir<in^ iiluiiittly from tliu tiyniun. I'liitoH of tlio ventnil Uisk pniiioiiioimll)- liirgc, ami ciiiivi'X.

Jliri-.oa itiid Loi'iililij. — I.owui' Jliirliiiglon linii-i^tonf ; Hmliiigton, lowii.

T'qn' in llic (Wortlii'ii) Illinoi?* State L'olkrlion, Spiinyliilil.

licimiiki*. — Tlio upofinii'M wiili iuium liguicd li} llall in tin' Ilulli'tiii of Is; J is tdtally (lilU'rent from llif tvpo in llie Woillii'ii coili'i'lion at S|iiiii^- lii-lil. In till) fiii'iiiot' till' arm litMii'iiig pla'cM arc liori/oiital ; while in tliu latter they do not expand at all, and the ainin wei'e evidently ((nile delicate. Hall desciibes the anterior tfide ol" the type xpecimen w extending out more prominently, and iio regards thii* an posNiiily of xpeeific value. TIiIh pronii- iieiiee, however, oecnrs in the left posterior ray, and not in the anterior one, and 1.4 incidental, and not ul' structural importancu.

CaOtOCrlnUS OXtOnSUS \V. ami Sr. (imv. Rpoc).

I'htlc l.\ II. Fiys.O, 7.

(Fifriirfd liy Hull, \^'i, in Hull. I., Niw Vnrk i^inii- Mii«. Nut. 1Ii»t., ns AeliHoerlmii ttrarmalun.)

C'loxely allied to C. llnl(K. luit smallrr and the plates more iiodoso. Dorsal cup gradually spreading' to the tup of the ct)stalH, thence rapidly, aiuiosl horizontally, to the haxe of the free armx. The platen of the rays rising into transverse, ongular tubercles, with obscure Btrisv. Interbrachials and inlerdistichal spaces deeply depressed ; the plates of tlie former cov- ered with round noiles.

Uasals .short, forming a slightly ]U'oji>ctiiig, trilobate di>k, deejily indented at the suture lines, and excavated on the bottom ; axial canal small and pen- tangular. Hadials larger and miu'e ])roininent than the costals, once and a half u.s wide as long. The two costals of eipial size, both narrower than the radials. DistichaN as large as iliocostals; all axillary. Palmars consider- ably smaller, the inner ones axillary and supporting two arms, the outer ones ii single arm. Ann openings thirty, almo.st e(|uidistant. Arms rather heavy and closely packed ; they pass out almost liorizontally from the calyx, then curve upward, infolding at the tips. Inlerbrachial spaces: 1,2, 1, and a minute piece on a level with the arm bases. Anal plate succeeded by 2, 2,

\r 1 :

II

1

M

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A(TIN(« lUNrn.K.

617

nntl 1 pliitc. Vontrnl dink roniiul, nlinoNt n.t liij^li n^ flic dorsnl cup ; jfinil- iiiilly piiH)iiii}{ iiilu llic iiniil tubo. Tlu> |iIiiIch of tho di.^k ),'ni\v >'iiiiilli'i' nit tlicy ii|i|ii'uiicli tliu iit'iii Iiiihon; tliu ui'iiIm mill riuliul doiiic pliiti'^ liii'^rcr niid Nli'on^rly iioduMO ; tliu intervening^ NUialler omcn r<li;;lilly ti.iiiid. An(d tulio Ntuiit and loii^, oxtcniling conxidoruldy (dtuvc tliu ti|m ul' tlio nriiix, nnd cuin> |iimi>d of Niiiiill, tiiiiiid pliilcs Till' joints III' tlio Ntciii vai'V oiiii!<idri'idily in width; Miiiii' III' (III) iiiidiil jiiilitN ill llic upper pint iiii' iiciirljy tlii'ri> liiur" nn wide MM till) inturiiodaIi4, nnd nru pruvidud >villi knircdiku vd^i>n. wliilo llio odgi'M III" till) iiiti'iiiodali* nro but very litlU' convex.

J/i'ii-Dii mill l.iiiiililii. — FiOwer niirliii^lon liiiii"<tiiiie ; ])iiilin;>'toii, lown,

Ti/pvs ill tlio collection of Waclisiiiulli and Springer.

* «•<»•

Caotocrinus multlbraohlatus llu.i.. riiilc I.Vr Fi,j. (I ami 7, mil Pink A Vlll. Fi.j. S.

1S5<. Ji-limiriuiit mHllilifin-liiaUii — Ilir.r.i (icul. Hi|.. lunii, Vul. I., I'lirl II , p. .'.mi, I'liilc ID, Kirf 10.

ISSl. Aiiinufriiiii) Hiiil/i/iiiiiiiiilm — W. nml f*l'. ; Ui>i'.ii)ii I'liln r., I'lirl 11, |i III.

Byii. Jflimifriniii Miilliiniekiiiliti yttt. riiiiiiifiti Uwi; IIimt Ni w ,S|i(i'. Ciiii . p. Id

Calyx gradually and evenly Hpreading to the hnsofi of the free aniiM, dim tiiiftly truncated at the lower end. and slightly depressed lietweeii the rny.«* nt the anil regions. 'I'ho ventral disk fully one third lower than the dursiil cup, mid Hurmountcd hy a moderately large, nliiuwt central tiilic. Plates of the dorsal cup nil marked by ntrong radiating ridges ii.oceeding to the sides of the plates, and meeting in the centre, where they fnrm a conspieunuH niigular node, which is transverse upon the radials and costals. The ridges passing lip and down the radials and brachials nro more prominent tlian any of those proceeding to, or coming from, the intcrbrachials. Iletween the radials and basals there are three such ridges, or four where the former rest upiiii two basals. while the other plates have but one to each side,

Hasals short, their lower margins projecting outward, forming n .slinrp rim, which esteiids beyond the sides of the column, and is deeply notched nt the sutures. Hadials nearly as long as wide. First costals one third smaller than the radials, throe of thorn hexangular, the two posterior ones generally lientangular; second costals n little smaller than the first. Distiehals still smaller, nnd all axillary ; tlic outer ones sujiporting nn nrm. which is free from the second or third plate ; the inner ones two pnlmnrs, of wliich ngnin tlio inner one in both divisions of the ray is axillary, and supports two arms; the outer one is truncateil, nnd followed by one nrm ; nil nrm-bearing plates

1

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i

CIS

Tin: cKixoinr.v c.vmkuata or Ni)i!rit amkimca.

sliglitlv projecting oiitwnnl. Arm oponiiigs almost oquitlistaiii. the respini- tory pores small. Arms eight to tlie ray, when normally developed, hut rays witii seven or even six arms oceur (piitc frequently ; they me somewhat llaltencd, and eoiniiosed of two series of transverse, rather short and appar- ently smooth jiieees. Regular inttM-hrachials : 1, 2, 2, I in mature speci- mens; tlie first the samo size ns the first eostals, the upper one very narrow, and wedged in hetween the upper row of hrachials. Anal plate followed by 2, "t. 2. and 1 plate. Ventral disk depressed conical, the plates near the sunniiit railier large and sharply nodose, those near the arm bases somewhat smaller. Anid tube long, moderately thick, composed of short, transverse pieces, with shar]) i)ro| "ting edges. Column of medium size, the joints rather short, the nodal ones distinctly angular and slightly projecting.

Jliin'yti iiikI l/ii-(tliti/, — Lower Turlington limestone; Iiurlington, Iowa.

Tiif'i in the ( Worthen) Illinois State collection.

Ji' ludi/,-'!. — .\pproaching '''. rivldlux in tin- form and ornamentatiini of the dorsal cuji, but the tegmen of that species is comparatively higher, more conical, and the plates of the anal tube are larger and more nodose.

Cactocrinus ccslatus Hail.

J'hitc 1.1 X. FnjS. S, !).

I'.".''. .Irtiih.-rlaui cirli-iK— IIm.I ; (ir.il It. p. l.i\v;i. Yul. 1., Viirl II., |<. rl^.■|, I'latc 10, Figs, 14<», h, 1">"<1. .1 fiiiuiTiii/it iviA(/«.< — \\. :iiul Si'.; Ur\isi,in I'liliocicr. , I'.iit II., p 1 |,'t.

Larger than the preceding species. Calyx short-subfusiform and highly ornamented. Oors.il cup one fourth wider than high ; uniformly spreading from the Itasals to the lop of the arm-bearing brachials. A'eulral disk sub- conical, almost as high as the cup. the upper j>art drawn out, and passing im]iercfpiibly into the anal tube. The cup ornamented ns in C. wn/li- hnw/iidlii.-i. except that the eostals are connecle(l among themselves and with the radial,^ by three jiarallel ridges, in place of one, as in that species.

Base short ; the sides neither spre.iding upward, nor projecting on the lower margin ; the lowei surface sulliciently excavated to enclose the first stem joint ; interbasal sutures distinctly grooved. I\adials a little wider than long, and much larger than the costal-. The higher brachials arranged ns in C. niiil/ifitwhiiiliis. Arms eight to the ray. slender; gently curving nt their bases outwanl aiiii upwanl ; the tips, so far as observed, not incurving,

AtTIXOCKlMi:.

GIO

but aoniewliiit (lecroaslng in width ; modcriiti-'ly lliitlcueil on the butk, Imt witlioiit siii't'iice maikiiigs; the sides siij^iilly di'iitiitc. Tiie spines of llio |piiniidi'.s nitlier short. Interbracliials : J, 2, li, 1, tlie fust a liltlu larger than the costals. The anal phitu, wliich is generally nanower than iho railials, siH)ports 'J, .'5. 'J, and I jjieee, the latter Ibllowed by a narrow elon- gate plate, placed between the arm-bearing brachials. Interdistichal space.s deeply depressed, and the centre occupied by a .small, nodo.se jilate. Ven- tral disk very iiigh. the interambnlacral spaces .slightly grooved toward the arm regions. Plates more or le.ss tmnid, irregular in form and si/.e. OraN indeterminable, and possibly unrejiresented. Covering pieces of first and second orders represented by single plates ; the .succeeding orders by two rows of small alternate ])ieces, which take part in the tegmeii. Anal tube strong, constructed of similar i)lales to tho.se of the ventral disk, but some- what smaller. Column apparently small ; a\ial canal large for the genu.s and (juincpielobate.

lliinziin iiiifl hii'iiliti/. — .'^ame as last.

Tiji'C in the (Worthen) Illinois State collection.

i

^

Cactocrinus coolatus v;u. spinoteutaculus ll.vi.i..

Pl<lk LIX /'/;/. /().

I^IU . .t,-/iiiiirrinii.< .y,iiif:*iii/,irii/ii.i — II M i. ; Sii|i|il. (ii'"l. lii'p. l.nv.i, p. Sll ; N. Y SImIc Mii^. Niil. Ili>l ,,

Hull. 1. (Is.i). I'liitc ;t./, Imus. in Ic) 17. l'i>.i .l,-'iiiu,'rii!«' '/iiii"ti'ii/iiri'liii — \V. ami Si'. ; l(i'vi«i'ili IVilinu'i- , I'nll 111., |>. 11'.'.

Agreeing with C vtvlitlioi in the lunnber of arms, the arrangement of the ])la es, and their style of ornamentation ; but departing from it in the form and proportions of the calyx, which expands abruptly from the distichals, and is at the arm bases almost as wide as high. Ailiiinrriiiiis fjiiiintcKhi- cii/its is in our opiniini only an extravagant form of Ciicfurriiuis cwtnln.i, in which some of the arm joints, which in the latter are fi'ee, were incorpo- rated into tiie caly.x ; and this, together with a slight increase in the thick- nes.s of the arms, fully explains the niodilications above mentioned.

ll<iri::iiii nm/ f.niiilit'). — Same as last.

T'lpc in tiie University Museiun, Giitlingen, Germany.

I \

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T

620 TUK CUINOIUKA CAMKHATA OV .SOU 111 A.MKHR'A.

CaotoorinuB fossatua s. A. jiillf.k. Plate LV. Fiij. 12.

1S'.12. A'linoennuffoDutai — S. A. Millkr ; Adv. Slieils ISlli Rep. GpoI. Surv. Iniliann, p. 10, Tliite 6,

Fip. II aul 12.

Cal^x nioderatol}' large, subovoid. Dorsal cup truncated at the base, the sides a littlo convex ; height and width as 3 to 4. Plates rather delicate and deeply sculptured. The middle of tlic plates occupied by a sharp nugul;ir node, from which angular ridges, one to eacli side, pass out to the margins, wiiere they meet with liiosc of adjoining plates. Angles of the plates depressed, tlie suture lines rather indistinct.

Hase siiort. projecting laterally, and forming a rim, which expands be- yond the colunm and the lower face of the radiais, and is sligiitly notched at the interba.sil sutures. Columnar cavity rather shallow. Radiais wider than long. First costals about two thirds the si/.e of the radiais, hexagonal ; sec- ond costals a little largi r than the first, pentagonal or hexagonal. Di.s- tichals, pahnnrs, and post-palmars all axilhuy, the post-palmars sujiporling the free arms, of which there are eight to the ray. Ambulacral openings almost equidistant, the interspaces between tliose of adjoining rays a very little the wiilest. Intcrradial areas arched by the post-palmars ; those of the regular sides consisting of five plates : 1, 2, 2. Amil [)lale as huge as the radiais; followed by '1, '^. and 2 smaller pieces. A'ential ili^k highly convex, only one Iburtli shorter than the cup ; covered with large plates, and each of them prolonged into a heavy spine. Orals pushed to the anterior. Anal tube almost central.

ILnr.iin (tail F.iiculili/. — Lower Bmliugton limestone ; Sedalia, Mo.

T'ii)e in the collection of S. A. Miller.

Ji'cwfirks. — A[)proaching C. roln/ns in the form and ornamentation of the dorsal cup, and also in the number of arms ; but differing in the form and construction of the ventral disk, which in the latter is higher, and gradually tapers to the anal tul)e, instead of being highly convex as in this species. In C.fiissatu.'i the disk plates are le.ss numerous, almost of uniform si/.e, ami each one is extended into a long, heavy spine ; while those of C culntus vary considerably in size, the principal ones being slightly nodose, and the otiiers almost llat.

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ACTIXOCRIXID.K.

021

Caotocrinua ornatisaimus w. .iii>l Sp.

riate LVH. FUj. J.

ISS". A'-liiiorriiittt nriiiiliitiiiiut — W. .■iml Sr. ; (ii'nl Kcp. lllirnii^ (l"<'.lii), Vnl. VIII., |i. ir,:i, pl,,!,.. Id,

Fi),'. '.I (""t I'latc i;, Kii,'. :i), 1S90, Jcliiioeriiiut nrii<ilhiiiuiit) — !S. A. Miixtui N. Ainer. (ieol. ami I'lil., p i\'J.

Of inediuin size, .i|iec'iiiions of liglit color. Dorsal cup dciircssed, semiglolto.se ; liuiglit eiiual to lialf its widtli ; plates delicate and liigld^' ornanientod, but not convex; suture lines dilllcidt to see. The surface is niarketl liy a system of sliarply elevated, very prominent rounded ridge.x, pas.sing from plate to plate, and meeting in large stellate (dusters in the interbrachial spaces; those following the middle of the radial seiies are widest, and pass from the hasi-radial suture into the arms; they increase in width toward the arm ii.ises, and divide the surface into five well defined pentangular fields. Scattered between the ridges there are head-like nodes, and the ridges are more or less undidating,

Hasals short ; forming a small rim, which is slightly nolclicd at the sutures. Hadials and costals decreasing in size in ascending order, all wider than long; the first costals (piadrangular with convex sides; ihe second generally lieptangular. Dislichals and palmars one, except in the outer divisions of the rays, in which the (irst pahiiiir is succeeded l>v two to three ciinealo plates, which support an arm ; while the inner ones are axillarv, and followeil liy two post-palmars with two arms; there being normallv throe arms to ea'_'h main division, ami si.x to the ray. Arm- long, nioderatelv stout, rounded on the back, their tips curved and folded inward; they arc composed at their bases of cuneate pieces, which inlnlnck aiul gradually become biserial. every second to fourth joint of both series being long, and bearing a conspicuous, looih like no(le. The intervening joints are mucii shorter, and comieeted longitudinally by waving sutures, riiinnles closely packed and contiguous; compo.sed of short joints, and each one arine<l with ii short hook. Interbrachials comparatively large, occupying fully one iialf of the whide interbrachial space, and rising to the middle of the second costals; there are two jdates in the two succeeding range?, which are fol- lowed by the interandmlacrals. Firs' anal plate as wide as the radial-, and often liigher, supporting 2, ,^, and 2 i)lates. Intordistichals generally three, with frequently a small interpalmar. Wiitral disk .short hemispheri-

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Q'2-2

TIIK CIMXOIDKA C'AMKKATA OF NoIIIII AMI.ltU A.

ciil. jiiivi'il Ijy siiiiill, iiTogiil;ir iiicce.", intiTspersod with iiodo-^o larjior ones. OiiiIh jnopoitioiiiilly Minall, as also the raihal ihtiiie plalos. Anal liiho cimipaiativi'ly small, ami ai)iiarently .short. Column composed of joints alternating in si/e ; tiie inteniodal joint.s knife-like, the nodal ones roinided at their margins, ami slijihtly crenulated. A similar crenulalion occurs also nt the rim of the basals. j^iviiig it the appearance of a stem joint.

Hiirhiii ami Lnn/i/i/. — Kinderhook group; Le Cirand. Marshall Co., Iowa.

7//y*'.s in the collection of Wachsunith nnd Springer.

Hiniiirk". — This species resenddes .|(//«(ic/v'/i».« tuiiitsiHlpliis in the style of ornamentation ; hut dilTcrs from it decidi'dly in the arm structure, and the form of the ventral disk, which i- vt'ry nuuh lower, and the anal tui)e much smaller.

C(tn\r/!.,ii. — The sjiecimen represented hy figure " on Plate IT. Vol. \'III. of the Illinois (ie(dog!ca! lieport. which ^vas referred to this species, represents a good e\ann)le of (.'((i'l"n-litn.t AiH"ldl.

CactocrinuB nodobrachiatus w, ami Si. rinU LVII. Fi,,s. I ami J.

1SS-. .l-/immiiii< „U,U„.-^i„/«<-- \V. .■iii.l Si^. ; (Irul. U,-|). llllimi.. (bnn). V"l VIIT , p. 1(15, Pliitf 15,

Kiff. :>. I'laii' 1(1, Kii: In 1'<'.I0. .1'-linm-riiiin iiii'lnl,i-ih'lii,i/ui — S. A. Mii.i.KIi; N. AiiiiT, (iinl. mill rulirmil., |>. iVi.

Specimens huff colorcil with hrownish tint. Dorsal cuj) inverted htdl- shaped, the sidi's luodi'rately convex, ahrupth- spreading lielow the arm hases. Plates decidedly convex, deeply pitted at their angles, and covered with radiating ridges, which, though moderately well defineil near the ''dgcs of the plates, are in the central portions either otiscilcte or lieconie imlistinct, i\en in well lueserved specimens, and apjjear as if they had hecn worn olf liy .itlrilion.

JJa^als short, expn:tding into a e(uispicuons rim with a sharp edge, wliicli ])rojccts lieyond liie limits of the coluiini; interhasal sutnri's deeply notched, giving to the hase a tri])artite outline. IJadials and costals decreasing in size upwards, the former as long as wide, the latter wider than huig. First costaN hcxangular, sometime-' jientangular, or even (piadrangular when not in contact at any side with the interhrachials of the second range : the cecond costals almost twice as wide as high. Disiichals one, smaller !h;m the costal a.xiliaries. Palmars one, small, (he two inner ones u.\illary and

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ACTINOCKlXID.i;.

023

followed hy two arms, ilio two oiitur mipporting one arm oiicli, tliero l)einj; noniially six anti.i to tlie ray, exceptionally live. Anns equidistant, crowded at their hasi's. and liending abruptly outward ; they are very long, rounded on till' haek, and taperiny; tho tii)s infolded, descendinj^ to the top of the calyx. The baek of the arms covered with two series of rather large nodes, whose sharp points are directtMl u[iwards. These nodes are larger than those of the preceding species, hut not so regularly arranged, and are farther apart; they are not confined to one plate, hut generally extend over two or more, sometimes even encroaching npon those of tho opposite series. Pinnules long, constructed and arranged as in C. oriiii/i'<iiiiius. Regular interbracliials live, the two of the second row almost as large as the lirst. Anal plate, which is generally a little narrower than the radials. supports 'J, 3, and 2 plates. There is one interdistichal, hut no interpalmar. Ven- tral disk heinispliericid, covered hy largo spiniferous plates, separated by small, almost Hat pieces, 'f he posterior onil is erect, and forins a part of tho ventral tube, which is almost central and comparatively short. Column moderately strong, composed of alternato largo and small joints, rounded on their edges. In a specimen before us in which the stem is preserved to its di-ital eml, it measures nearly 27 cm. The npper half is stouter than the lower half, which ultimately tormirir.tes in a fine point, and is for some dis- tance provided wiiii small branches, too delicate to have .served as a means for permanent attachment.

Hiirirum and Lunilitij. — Same as last.

T'/jirs in the collection of Wachsmnth and Springer.

I'i'iiiKr/.-s. — Diir.-nig from the preceding .species in the stylo of Its orna- mentation, the abrupt spreading of the calyx near the arm bases, its greater length, and in the large, spiniferous plates of the ventral disk.

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IIIK CKINttlDKA lAMKHAlA UF MtHIH AMKllIt'A.

CaotocrinuH Arnold! w. and Sp.

riali LVII.I'

lys.

18Sr. .l-limi-rliiKf Ariii.ili — W. iiml Si- ; (irnl. \{,\u (,f Illii.uis (1^00), p. lf,S VhU- 1", Fig. 10, auJ

Fitf. ;t.»

iMHi .I'/iiiui'i'iimi Jruiil.li — S. A. Mii.i.Kii ; N. Aiuit. (ii'ul. aiul IMii'onl., |i. i\i.

Of iiK'ditiiii si/0, wiili loinr, sIcmltT s|)ri>mliiij? nriiis, ninl fan-liko fririfics of pinnules. Form of calv.x siilpovalo. jjIIiIidus Ih'Iow, s]ii('H(ling at tiio iinii bases. The r^iM'face of liie plates iiiili'iited willi niiiiieroiis shallow pits ami sliort grooves, wliose rims, wliioh iirc somewhat rounded olV. connect wilii

■li other from plate to plate, and on th

dati

.•ting

rni-

mime

{•iies. all of wliii'ii produces on the surface a .soniewliat irregular, cancelluto sculpt ining.

Hasals short, without projecting rim ; the sutuvi' liucs not grooved, liadials large. First costals hexiuigular. iialf the si/e of the I'adials; the second still smaller and lieptangular. !>isticlia'' iml palui.iK small. Nundxr of arms varialde. from four to six to the r.iv. — six oeing the exception; they are heavier tiian in the preceding -specie-*, less crowded, and comjiosed of a (iouhie row of verv short pieces, united longitudinally hy wa\ ing sutures; they are ornamented on the hack in the uppi'r portion- liy two rows of sm.dl nodes, one to each plativ in ihe lower portions hy a more |proininent node on every sixtii or sev'fi'li plate. Piuiudes long ami in tdose contact, the proximal eight or nine joint.i provid'.-d with conspicuous hooks, directed upward, ami forming wiili corresponding hooks of adj(. ining jiiinudes regular rows, jiarallid to the arms Ii'eg'ilar interhnudiials six or more; llu' lir.-t e(|Ual in -izi' to tlie first co-.t;i!s, ihe two of the second range to the .>iecond cosials. the upper ones consideralily smaller. The anal side consists of ahont eleven plates, iho tw<i u]i])er ones resting hetween the nrni hases, nnd in con- t.ici wiili the andiidaerals. \'entral disk depressed hemispherical, occupviug les-i than one third the height of the calyx. It is comi)ose(i of numerous very Ml' ill pieces, of Irregular arrangement and nearly e(|iial si/c, most of them ilat. with a few convex pieces scattered among them. Anal tuhe sMitil. ^lightly excentiic, nhrupily rising from the ventral disk. Column composed of short joints of nearly uniform width.

Jloi-ivn am) hiiinUtii. — Same as last.

* Sm' currocliiiii uiulir Oitloerinm oniiifiisiiiiHn,

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ACTIXCXIUXID.E.

r.25

Ti/pe ill the collection of Hon. Uflos Arnold, PasiKk'im, C'alifoiiiiii ; oilier Hpcciinc'iis in the collection ot' Wuelisimitli and S|iriiiger.

llemarks. — Tliis (tpucioH diflors from C iioiiiibrarliiutus in the mimiler niiiiiliur, mid tlic less spreading ol ilie nrm;*, ns well ns in the ooiiftnii'tion of tlie veiitnil disk ; from C. 'inuiti^siniiin in tlio form and proportions (jf tliu dorsal cup, and the ornament. aion of the plutoM,

; '"^-

Cautocrinus glans Ham..

j'i'ih iJi: r:js. .:, ci. i, ,".

ISfiO. Arliimeriims ijliins — lUl.l.; Sup|p| (iinl Hip. Iuhii, |i 10. ISSl. .l,-li,iii:'rii,ii%^l,in!i—\\ :i 1.1 Si' ; UiM^iuu l';ila..n .. I'lrl II., |i I i:!.

1S93. ./V/;/i«r//(»» _///.//)»— WiHTnu.ii, .\Iiin. Am. Mus, Xiit Hist. New Yurk, Vol I., \\. Jo, I'liir I., Fii.".. ll", \i. Svil. .kliiioi-i-iiim lliiilm \\\\\.\ l'>i'iii, Sii|.|il. (in, I, Ui-p, Inwn, p. :i.-). 8vii. .Irti 11,,-riiiiin rr;i.r IIm.i.; ImU, DixTip. Ni « I'lil. Criii , p. li!

Hsn. Ji'liii'hTitiHs lllidri S. A. .Milleii) \i'Ji, Aih. blails lii-nl. Surv. Iiidiuiiu, p. 'i^i, I'iiilr .i, Fii,'«. i'l anil lis.

A rather large spepie.i. Calyx suhovatc. a little longer than the width at the arm !)ase.s. Horsal cnp abruptly spreading above the distielials, its height fully twice that (il the ventral di>lv. Plates of the dorsal cup from almost Hat to nodose ; the .surface smooth, except tiiat the radials oeea>ii(n- ally show faint indications of striio at tluir lower ends. Suture lines rather distinct.

Hasals large, forming a cup. twice as wide as high, a little excavated at the lower end. its sides slightly spreading or convex. Itadials twice as largo as the cosfals, longer than wide, the upper sloping faces much shorter than the lateral ones. Coslal.s as wide as long, tiie first hexagonal, the second hi'|)tagonal. I'almar.s in contact laterally, each one .supporting an arm, which is free from the second iilate. Arm I'acets large, directi'd ob!i(iiiely npw,ir<ls. and concave; th(! resjiiratoiy pores placed very (dose to the aiubn- lacral openings, and the thin partition walls rarely intact ; ambidaeral o])en- iugM nearly equidistant. Arms twenty, very long, moderately lieaxy. and rounded on the back, the tips not incin-ving. and tlie spines of the pinnules small. Regular intorbrnchials from eight to ten: 1. '1. 2. 2. 2. 1 ; gradually decreasing in size in ns(^ending order. Tlio anal plate in large specimens is followed by 2. 3. 4. 3 and 2 plates. V(>rtral disk regularly convex: com- posed of but few, comparatively large, and almost flat pieces, of so irivgular arrangement that neither the orals nor radial dome plates can be recog-

70

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OJG

TIIK CUIXOIDKA (..VMKUAIA Ol' XuUill AMIMUIA.

ni/.i'il. Aiiiil tuliu very l'>iig imd slciidur ; coiiiposuil iif .small. tniiiHVerso, ll^it pii'ce.s. Coliiuiii iiUMlenitciy tliiok ; llio noiliil ymiU long, ii lillle |ii(ijt'i't- iiij^, mill tlioir outor eilgus »lij;litly convex ; tliu uxial caiml luigo uiiil ^limply poiitaii^iiliir.

J/"ii:"ii mill L'lidli/i/. — Upper lUiiliiigton limestonu ; Iliirliiigton, lowii.

7''//" in the ( Wdiilien ) Illinois Stiito Cullectiun, Spiiii^rlielil.

Jit iiiiir/:s. — Thin is ii variaMe speeies. and tlie ()id_\ one of the geiins Nurviving the fjower Hnrlin^ton bed. The plates of the calyx vary iVoni .scai'cely convex to highly nodo.^e ; specimens having the lirst kiial of plati'.s Were described as ^liliii"irliiiis ij/nns, and those with the latter as ..I. l/inlns, l.'iu\{iv AitiiiiiiiiiiKs iiy.f Hall redeseribed a (bird specii's. in which the arinu and anal lube were preserved, but ind'ortunalidy. in his pholographic plates of eleven year.s later, he confoMndcd the specimen, which we have examined in the Mn.senni of Comparative Zoidogy. with rtricvhuvrlniis White!, u species with branching arms, and witliont anal tube.

TELEIOCRINUS W. aiM s, .

f^Sl. \y. .•111,1 Sr. i n.'visi ,„ i';il,r..cr., I'iiil II , p 1 H; (Pronid .\oul. Xal. Sci I'liilii,, p Mn). 18'^'J. S. ,\. Mii.l.Kit: Ni.rlli Ahht. (Ini hihI Puliruni.. p. Jsil.

Sni. CiliiHiiicriiin^ \\\\.\.\ hiij (uni tnu Mcur l^ts) in |inrl ; llcsrr. Niw l';i!nci/.. C'riu . p, \i.

Smi S/ruf,„-riil(4< .S,-iMi..M /;) MhIK :.li,l WiiliriUS; (m"1. H. p. |lllii..i>, v.. I II , p. I'.in.

A mollified and extravagant form of ('iirt'icriniis. Calyx obconical to iho base of the ])almins, then spreading horizontally, and forming a broad ami continuous rim arouml the calyx, frt)m the outer margins of which the IVeo arms are givi'n oil to the >i(ies. X'entral disk short, supporting a long, nearly central anal tube. Ornamentation of the dorsal cup similar to that of Artiiini-riiiiis and ('(ictdrrinns. but somewhat conrser. and the nodes more conspicuous than the striaiions. often oliscnring the liilier. Rasals three, large, massive, more or less ]irojeeting beyond the sides of the cidumn. Hadials and costals generally as long as wide or longer, but the costals in proportion c(nisiilerably smaller. Distichals 1 X 1(1, all axillin-y. sr'parating the rays into two divisions (but not into lobes), vhicli sniidivide In alternate bilurcation from eery successive brachial to the last in the oal\ x. which licars two simple arms. The successive orders of brachials of the two divi- sions arc very numerous; they invariably consist of a single row of plates, and in each or(ler only the plate of one side bifurcates again ; the opposite one is truncate, and is followed by a variable number of other plates of the

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T

ACriNOdMNID.i:.

027

i

Hame oiilor, \vlii(;h Ik'couic I'li't' iiiiii [iIiitcH iit tlic iiiiirj,'iii of tlic rim, Tlu' viuiuus merit's tliiiM foniK'il iiiv in roiiliu'l liitcnilly. ninl iiiiiU'il Ii^- Mitiiii' willi t'.'U'li oilier; tlione of (uljuiiiing rii}", iih well iis lliiisc ol'ilu' .•-aiiic ni_\ , funning; toj,'i'ilicr till' pi'culiiir rim whicli KiirromiilM Iho cal_\x at tlic Lrai'liiiil /oiir 'I'lii' pliitcs of tlie rim iiru of iR'iirly tln' saiiu' size ; tlicy form loiigitiidiiiiil. aiij;;iiliir riilj,'i'M, ami from tliu outer uiul ol' tMcli riilyo iiroccciN an arm. Arm o|)uiiiii}rH larj^c, all with a small rr.-'iiiralory poro at one siik'. Arm^ very nmiu'roiis, moilcratcly lonj.;, nimj)lu, cloxuly crowilod lo^rctlu'r. ami rnllicr small ill proiHiiiiou to tin' largi' >i/.i' of tlio calyx. TIu' |iiiiiiiiK's. so far a:* olisci veil. [iioNiilcil with well (Icfiiicil liooks. liiliMlii:iiliials nmncroiis, .scpar- iitL'il from the intcramhiilacral platt's hy tlu' lii;jhcr orili'rs of liracliiaN. gonorally from tlio palmar.-* up. liitcrili.-ticliiils om- or two. \'i'ntr;il ili.<k coiivc'N, ill form of a ten raycil star. slij;Iiily plicatci] near the outer mar;.fiii.'^, and compo.<ie(l of a lar^'c niimlicr of plate-', which decrease in .^i/.e outward. 'I'liu orals, although well ilidiiu'd in young specimens, can scarcely ever hi- idelUifiud in older ones. 'I'he inner tlooi- of the ti-Liineii is strengthened liy braces, which incri'ase in thickness as they n-cede from the centre, and on approaching the rim form tunneled passages for the reception of the amhii- lacrn. The ambulacra follow (liu inner floor of the disk. bei-i,' ])laced at a slight distance from it ; they arc roofed over wlndly (U- in part by super- imposed interambulacral ])ieces. wliicli. together with the radial dome plates, if present, form a rigid and imlependent covering iiIkjvo the food grooves, t'olumii covered with rows of angular ])rocesses, passing up and down it-i siiles at ecpial di-'tances. giving to the column a highly sculptured, angular a|ipearaiice, especially in it-^ ii]iper portions, where these processes are more jH'ominent. and in almost continnou-^ vertical lines. They pass out from the nodal joints, but intrude upon the intervening smaller ones, and grow farther apart with tin- increase of inti-riiodal joints.

Dislriliiitluii, — This genus, like other extravagant tbrM\s, has n ver\' limited geolojrjejil mid geogra|)bical range, being restricted, so far as known, to the Iturliiigloii group of the Mississippi N'alley.

7'///"' of the gemis : 7) li lurriiiiin iiiiilirnsiis Hall.

Hi iiiiiih!<. — We have called Tihi'irriniis "a modified nnd extrnvngant form of ('(ic/(irr!iiii:i" : nevertheless wo regard it as a good genns. It is evidently the lineal successor of that genns in the Upper IJnrlington lime- stone, Inu'ing the .same mode of bifm-.itlon of the higher brachials, and other genenU similnriticH. CwUnrimt.-! nourished abniidantly in the Lower Burling-

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C,'26

TIIK C»IX(>IIH;,V tAMKUAl.V nl Nolllll AMKItllA.

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ton, ami, with llie c'.\L't'i)tiuii of tlic abcriimt mid iloubtful C. ij/nnn, diil not ituivivo it. 7'(/(((«r(/nM is iTpifHciitnl in tlio lower bcilH by a Miiijjlu transi- tion Ibrni, but buiMUic fMtulili.xlK'il in the Upper lliiilinj^luu to the extent o( live Hpecii'rt. The phjilogt-iietie ili'Velopiiii-nt is iippareiil : 'I'lie ariiiK of thin ;;ioiip lieeaiiie ho nuiiieruiis ami erowileil thai they were naturally pu>heil outward Ibr want of room, and their base!*, bein^ in Mueh vIom' eonlaet as to he iinimivaldc, became united by HUture, and thuM formed ih<. rim. Other moilifii'ationt took place simultaiK'ouHly at thf inner lloor of tin- (li>k, where tuiiulai' pasMa^en were IbniU'd lor the icccption of the aml)ulai-ra ; and the cohnnn, which in this group in eomparatively small, was strengthened by longitudinal brnceH.

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HM. 188'J.

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TeleiocrinuB umbrosus Haif,. riiifi f./X. Fxj. r, «>nl I'hii, A A'.. /V;/... Ja-,1

At'liiiorriiiii$ HmliiiKHI — llii.l.; (iinl. !ti'|i InHii. Vul. I.. I'lirt II , p iiW). I'liiti- U, Fiir^. %i, b, Sli-i./'«-riiiii.< Hmlirii'ii' — Milk iiiiii WiiKTMiN; (iriil. Id |i. Il|[ii<ji», Vnl. 11,11. 11)11; ami ibid,,

Vi.l. v., p. :ii;(», I'liiii- «.. Kiu'. .V

T'lri'«'ll'IHI Hlill,ri:.'H! \V. IIImI Sf. ; IlcviMcMl I'llllfnlT., I'llM II , |>. 1 l!l.

T'liii^'riiiiin Huhrmin — S, \ Miii.ni; \. .\. (inil. nnil I'lilif'iil., p iJ^ll.

Svii. JrtiHiirrinui irgiliiji) IIm.i.; iMiil, Siippj. (huI. Hip Iciviii. p .1.

Svii. .V'r..^«'/-/«»» rfyiA.//.! — Ml KK .iiiil WiiliTliKS; (irul. Idp. Illiiiiijv, Vnl. II., p. 190.

Sui. T'l'iiii-riuH) :riiili'ii» — W mill Sp ; llr\i»iiiii I'liliivirr , I'^ii'l II . p. 11^.

8vii r/fi'.i'W/KH (/v/i/.j/.t — Wiiitnu.ii; bun, .Mi m. .\iii .\Im^ N.iI. 11i,i N. Y. p 21, riiito J,

Ki«r i', is. Svii. .kliiiwnHuii ,l,lir.ihn M. nuil \\ . ; Ci-ol. Rip llliii,,i,. V..1 V , p, lU.'l, I'l.'ilr >>, V,'^. ?.

A miiderately large species. Calyx about ns high ns its width at the ann bases. Dorsal cup conical to the base of the rim. which rises from above the di.-lichais. \'entral disk dome-shaped ; its height e<|uid to one third — or loss — tilt' ill ight of the dorsal cup. Itim wide, almost hori/oiilal. Platen exceedingly variable ; in some .^pecimenH oxtiemely knobby, w iih corrugated or uneven 4urface.s, in others merely convex and almost snu)oih; but most generally tlu'i'c me short ridges traversing the sutures, which enter the margins of the plate", and the miildle j)art is nodose. 'I'he nodes of the radials are large and massive, and like tho.sc of the cnstals transversely elongate, w hilc those of the interbrachinl.s are round and conical. The plates of the rim arc ridged longitudinally, and in the sjjceimen look like crowded frae arms.

Rnsals thick, strong, tliiir lower margins extended outward in a thick- ened rim, and downward in form of nodes, two to each plate, which project

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A(TIX(K UINrn.K.

029

DViT tlio niili'M of tilt" two or tlirt'i> pinxiiiiiil Htciii joints; tlio i<iitiiii' linc-i ili'i'|tly iiotilifd, tliu KntovcM rvavliiiif^ to llic liip <»(' tliu plali'H. It.nliiilM ii^t loiijC M vtU\o, nn<l nn Iiirj^t' ix" liotli cihIhIh tDgi'tlu-i' ; llui neroiiil comIhN

!<tllllllt'r tllllM IIm' (ll^t. I)icticllll',i4 IIH Iiliyc! lis till' IINilllHT ''iiMt;!!-. ; till' MIC-

ci'i'ilitig lii'iicliiiih iiiucli xiMiillcr, ^'iviii^ ull'(lii> iiiiiir^ in llic ii-iuiil wiiv. fiJirgu s[ii>('inR<n>< liiivL' Ncvcn hiliii'cnlioiiK in oncli main tliviwion, iiml licncc xixti't'n aniiH ti> tlu' \t\y, Hniiillcr oih's livu to nix, with twi'lvi- lo luiiitri ii muix. Anns of niodi'iMti' li'ii^'tli iinil <(nilc> ilt'liniti'. tlirir Itili'iiil iiiar;{ins •'I'lmli'il. Id'^'ular intri'l>riirliial.<< : I, 2, 'J. *J, (ftailiialiv ilccica^'ing in .-i/f npwai'iN. Anal plali* ^rniTiilly a liltio nnialli r than thi> railial.x, folliiwi'il liv '_'. |, :; nml 2 )ilati'H. Vonlra! i\\!*k ahnnst Hat at the iiiar)^'in. (1i)nii>-whap('il aliuM'. It i.i ('iiin|ii)s<Ml of hti'^c ami ^niiill iilatc.", thn r>ii'ini'i' iioiI(),«l>, iIm- laltrr convex and inti-rpo.""'"! hi'twt'iii the Iaij(i'r omoh. Anal tiilic ccntnil, Mlinit ami long, n.xinj^ ahovc the tipM of the arinx, nml conHtnictt'il of nithfi' Hiiiall, convex, trnnsvernely eldiigMte piecex. (Jolninn of li ss than niediiiin fi/e ; llic nodal join- lonj^, their outer marj^im* ereniilated. Iicinj; eoveied with niiineroUH , iongitndinal processes, which haiij; down ^li^dlllv over the intcivcniiijx Kinuiler joints.

Jlor'r.im nml I.iifiiJihj. — I'ppcr niiilinglon liiiu-tone, Itinlington, Iowa, (iiiincy, III., and oilier places.

7,'//" in the (Woillicn) Illinois Stale cidlcction.

J!i iiinr/.s. — We have cMiniined of this species over one hiindied speci- mens of all sizes, most of lliein calyces, hut some with llie aims iniiulicd, and find iniioiii;- lliem considoralile variation in the ornamentation (compiire I'late lA. Kig. -'I with -li), as well as in the numher of arm openiiij:s. without showing any other .strnctnral dilTeiences ; they even agree in the )ioc\iliar ami iiniipie ornamentation of the stem. A ciirel'iil coiiipari^on of these specimens has shown us no way hy which a separalion of I hem ciin he made upon any constant (diameters. We have ohservcd that the Miimger specimens have fewer arms than the older mies. and that the iimiilier of arm openings increased n» the rim grew larger, /. c, extended out rarlher. We also found that the specimens in their earlier phases passed throiigii the ('■I'lurriiius stage, wliere they had no rim. and in which Home of the higher hifiiiTations took place in the free arms (Piate r,X., Fig. 2'/). Among the calyces, the smallest ones have hut 4 arm oiienings to the ray. somewhat larger ones Ti, others .'n, 10. VI. or 14. while in the largest ones thcic jire Kl; phowing again how little reliance, in some groups, can ho placed upon the

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TIIK CUIXOIDEA CASIKKA'PA OF XORl'II AJIKKR'A.

iiuiuber of unii openings or the number of arms ns a specific cliaracter, unless tlie reliitivo niatiuily of the individual is considered. The two figures on Plate LX, give the most extreme forms of this species ; as a rule, the plates are neitlier so smooth nor so nodose as in those specimens.

Teleiocrinus rudis iIm.l. ri.ite LIX. Fujs. 1, 2, 3.

ISIiO. Artinni-rhntn rutli.i — IIali.; !Sii|i|>I. licul. lii'|i. lowii, \\. 133. 1S7'!. Sir;l;:-riiiiis i-iolii — Mkek :inil Woutiiks; Ciccjl. Kip. Illinciis, Veil. V., \i. 319. l^Sl. 'J'i'/riiicri//iis riiilis, \\ . anil Si'. ; Ucvisidii I'lilii'Dcr., t'liii 11., |i. 149. I'i^y. Tilri'irriiiiis riiilis — S. .V. .Miii.tii; Ncnth .\iiii'r. (icul. iiiul Tiilu'oiil., p. 2S0. Smi, Artnirn'riims ciiroxiH — ll.M.i. ; ISOl. Itoslun Jciuni. Niil. llisl., |>. 271.

.Sy/-o/(/(v/««.«<'///'(),t«< — .\Ikkk ami Woutiif.x ; Cicul. Hep. llliimis, \ul. V., p. 349. T'h-ioi-riiiKs c/ir,i.iii' — W. ami Si'. ; Kcvi>icin ralii'in'i-., I'ait 11 , p. 149. Svn. .Ir/iiiocriiiiis (Ciihi/liocriiiii.i) n-u'l/ix ll.M.i,; ISIil, I'lvliiii. Dcscr. I'alircjz Criii., |i. 12. S/m>urritiii.i rni/iis — Mki:k and "WoiniiKx; ISOfi, Vmi]. Hep. Illinois, Vol. 11., p. 190. Tf/iidfi'i'iiHs ero'/iix — \V. ,'iii<l Sr. ; Itevisimi I'alivcicr., I'aii 11., ]), 149. Syn. Ar/iihirriiiii.i {Ciil,illiiuTiiiu>) i,ixi-i(//,/ii.i II.vi.i, ; ISI'il, I'rclini. Dimt. Pal. Crin., p. M. S/ro/orriuK.'i iiisi-iif/i'iin— .\Ikkk ami Wouthkx; (iiul. Ucp. Illiuiiis, Vol. V., p. 349. Tiliiucriiius iii.icii/ji//(s — W. mid Sr. ; Ui'visioii I'alii'ocr., I'arl II., ji. 149.

A very nodose species, about the size of the preceding. Calyx to the base of the tube a little higher than its width at the base of the free arms. Dorsal cup obconical to the bottom of tlie rim, and fully as high ; the sides almost straight. The rim begins to expand from the top of the distichals ; it is directed obliquely upward, and is less prominent than usual in this genus. Ventral disk depressed-convex, somewhat decagonal in outline. Plates of the cup ma.ssive and extremely rugose, the surface being full of wrinkles and pits, and covered witii all kinds of nodes and ridges, which give it a corroded appearance. The basi-radial sutures are traver.«ed by several ridges, which generally unite at or near the middle of the radials into a prominent node, the centre of which is depressed into a deep subcircular pit. The middle part of the other plates to the height of the distichals is abruptly elevated into a large node, which is transversely elongate upon the brachials, and rounded on the intcrbrachials. The plates of the rim are marked by high, angular, zigzag ridges, which follow the different ramifications of the r.ays.

Basals large, irregularly thickened, their lower ends produced into six angular processes, two from each jdate, which pass down to the second or third stem joint ; they are deeply grooved along the sutures, and project in form of a tripetalous rim over the colunm. Radials large, their length and width about equal. First costals less than half the size of the radials, hexagonal;

ACTIXOCRIMD.K.

031

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the second still smiilkT, being considerably shorter. Tlie size of the dit>tich- als is but little less than that of the upper costali, but the plates of the suc- ceeding orders are considerably smaller. There are live bifurcations in each main division of the ray, and six anus, or twelve to the ray Arms moder- ately long, much larger than those of the preceding species, laterally com- pressed at their lower ends, and distinctly angular on the back throughout. The arm joints are transversely angular, and have a small elevation or sharp node at each end, giving to the section of the arm a trigonal outline. Pinnules provided with long hooks, similar to those of Cdctdcrlinis. Inter- brachials : 1, 2, 2, 2 ; the latter on a level with the distichals, and quite small ; the first as large as the first costals, or larger. Anal plate as large as the radials, followed by 2, 3, and about G irregularly arranged plates above, which are roofed by the palmars. Interdistichals one. Tegmcn moderately convex, slightly plicated -lear the outer margins, and composed of large plates scattered among smaller ones. The sutures between the plates dis- tinctly grooved, but the surface flat, and covered with wrinkles, which give it a decidedly granular appearance. Anal tube central, long, rather large around the base, but decreasing rnpidly to two thirds its largest size, and then tapering slightly to the end. The tube consists of .short, very wide Iiieces, arranged in transverse rows, and covered with wrinkles like those of the tegmen. It is surrounded at half way to the margin of the disk l)y an irregular ring of ten to fifteen large, spinous plates, which sometimes bifurcate, and rise to a height of from 40 to 80 mm. It i.s barely possible that these plates represent the orals and radial dome plates, or the latter ou]y, but if so their arrangement is very irregular. Colunni beautifully sculptured with six rows of large angular processes, longitudinally arranged, which give to the stem a distinctly hexangular outline.

Horizon and Localitij. — Lower part of Upper Burlington limestone, Burlington, Iowa.

Ti/pc in the (Worthen) Illinois State collection, Springfield.

Bcmarhg. — This species is most nearly related to Tcleincn'iiiis viiihro.ius Ilall, but differs in never having more than twelve arms, even in the largest specimens ; besides the arms are mnch stronger, and angular on the back instead of flattened. It also differs in the shape of the rim, and the aspect of the ventral disk, its wrinkled surface, as well as the long spines; and it is very distinct in the sculpturing of the column.

Comparison with the types shows that Aclinocrinus cliroKiiit, A. crodus, and A. inscidjjtiis, all described by Hall, are synonymous with this species.

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032

TllK CHINUIDKA CAMKK.VTA OF XOIMII A.MKHKA.

Teleiocrinus althea Hall. riitU LX. Fiff. 4, and Plutc LXIII. Fly. .9.

IbGl, Aiiiiiorriiius (Ciiliit/ioi-riiiiix) alllifii — Uali,; rrclim. Ucscr. Ni'W I'alii'u/;. Criii., [i. 13 (figureil Bull.

1. X, Y. Sliile Mils. Niil. lliM., I'liilr 4, Fijf. V^)- ISSl. Tclnucriiiin tilllim — \\ . niid Sr.; Uuvisiuii ralitocr., I'liit 11., \t. US.

A large specios, remarkable for the great length of the dorsal cup, and the reiiitive ishortno.xs of the togiiien ; the former being five times the long- est. Width of the rim, a.s compared with the length of the calyx, as seven to eight. Sides of the dorsal cup slightly convex to the top of the dis- tichuls, then curving outward and forming a broad rim. Plates moderately convex, covered with broad elongate nodes and interrupted ridges, alternat- ing with pits and grooves. The ridges, as a rule, are directed to the middle of the plates, but without meeting in the centre, which is occupied l.-y a more or less corrugated or pitted elevation.

Basals large, forming a spreading cup, of which the lower margin pro- jects but little beyond the sides of tli" colimm. Eadials a little longer than broad, and more than twice as larg<' as both costals together; the latter hexagonal and heptagonal, nearly of equal size. Distichals one third smaller than the costals, wider than long. Palmars ver\- much .shorter than the distichals, twice as wide as long. The succeeding brachials smaller in proportion, all much wider than long. There are apparently eight bifur- cations up to the edge of the rim, and nine arms to each division, making eighteen to the ray, and ninety arms altogether. Structure of the arms un- known. Interbrachials generally nine, in five rows, arched over by the post- palmars. The anal side contains fourteen to fifteen i)lMtes. Ventral disk almost flat, rising very .slightl}' : the plates without definite arrangement, slightly convex. Anal tube central, very large at the ba.se.

Ilurizun iiml LocnlHi/. — Upper Burlington limestone; Burlington, Iowa.

T>/j)e in the Museum of Comparative Zoology, Cambridge.

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ACT1X0CRINID.E. 633

Teleioorinus liratus Hall. rUUv LX. 7'i,j. 3.

ISOl. Artiiiocriiiiis limlm — \\k\.-L\ Siippl. (j"ul, Kep. Iiiwii, p. 1 (llgurccl 1S72, Bull. I. N. Y. Sl:ile >[ns.

Nut. Hist., riiitu I, fit;. ;i). 1S)01. Siro/ucriiiiis lii-dtim — Mkick iiiuI WoiirirKN ; Geol. Ucp. Illi, jjs, Vdl. U., p. lyo, ami l'^73, iljjil ,

Vol. v., p. 355, I'liite 7, l''ii;a. ia, b, c. 18S1. Teleiucrinus lii-n/n.t — W. iiiiil Si'. ; U^■n^i(m I'liliudcr., I'lirt 11,, p. 1 19.

Svn. .Ictiiweriiiiin siiliuiii/ifosii.i H\Ll i ISCU, Siippl. Gcdi. Ucp. Inwii, p. 3.

Larger than the two preceding species, the calyx more elongate, tiie tog- men higher, the anal tube much heavier, the ornamentation less rugose, and the coknnn stronger and circular instead of angular. Calyx urn-shaped, elongate-obconical to the base of the rim. Sides of the dorsal cup expand- ing gradually from the basals to the top of the distichals ; the rim decagonal, curving obliquely outward and upward, conspicuous b\it not broad. Sur- face of plates slightly convex, covered with well defined radiating ridges, which in parallel sets of three or four unite at the middle of the plates in small, transverse or arched, angular nodes, producing a neatly .sculptured ornamentation.

Basals forming a broad and deep, gradually expanding cup, slightly thick- ened at the lower margins; the interhasal sutures somewhat depressed, but not actually grooved. Radials generally a little longer than wide. First costals rarely more than one third the size of the radials ; the second as large as the first, and both as long as wide. Distichals slightly smaller than the costals. The branching of the two main divisions takes place from opposite sides, as usual in the genus ; there being five bifurcations in each division, or twelve arms to the ray. Arms of moderate size, some- what flattened on the back, and covered with four rows of rather faint nodes. Interdistichals generally nine : 1, 2. 2, 2, 2, at the regular sides, and about thirteen at the anal side. Anal i)late as large as the radials. Interdistichals one. Ventral disk higher than in the preceding species, gently curving upward from the margin of the rim, and gradually pass- ing into the anal tube ; its outer margin distinctly plicated. It is com- posed of numerous irregularly arranged plates, small pieces being interposed between larger ones, but, as a rule, the plates decrease in size toward the arm bases. Orals indeterminable. Anal tube very long and large through- out ; composed of similar plates to those of the disk, but they are smaller

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TIIK CKIXOIDKA CA5IKUATA OV NUUril AMKUICA.

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mill lla'ir .-luriici's conugutfil. Column loiiiulud iiiul stout; the nodal joints with undulated udgt's ; tliu iixial canal niodoiiitul)' liirgo und pentangular.

I['irl.:iii) mid Laadi/i/. — L'pptT Burlington liniextonu j Burlington, Iowa, and tiuinoy, Ills.

7'//y/( in the (Worthen) Illinois State collection, Springfield.

Teleiocrinus tenuiradiatus Ham.. riafv fJX. Fijs. r7 and (J.

JSOl. Afliiwi-i-iiiiis Ifiiiiirdiliiitii'— IIai.i.; J'riliin. Ucr-cr. Kcw J'lihi'oz. Crin., )). 12.

Js;;!, S/,;,fif,-ri„ii< (rimi,;i:liiilii'— Ml r.K iiml Wdiniii-x ; (icnl. ]{,|>. Illliinis Vul. V., p. .TW.

lS^l. Tvli'm-i-iiuia leiiiiinitlinliix — W. iiml Sr, j Hi'visiiin I'liliviicr., I'nrt Jl., p. 119.

A large species, remarkable for its broad rim, the great number of arms, and the flatness ol' the plates. Calyx urn-sliapcd, its height about eijual to its greatest width. Dorsal cup to the base of the rim as long as wide, or longer, the sides slightly convex. The rim rapidly spreading from the top of the distichals, its outer mai'gin at right angles to the axis of the calyx. Arm openings directed somewhat upwards. Plates very little convex, almost ilat ; the suture lines distinctly giooved. The plates are covered with nu- merous very fine and delicate striiu passing from plate to plate ; they are strongest at the .sutiu'cs, where they form small pits at the intervening .spaces; the plates are without nodes, and the ridges are generally less conspicuous toward the middle.

Basals large, forming a cup, which spreads more rapidly than the radials and costals. and at midway is .slightly constricted ; the lower margin sharply angular, and the bottom concave. Eadials a little longer than wide, and more than twice as large as the costals, of which the first is hexangular, the necond a little smaller, and hcptangular. Distichals almost as large ts the second costals. The palmars and succeeding brachials forming the rim grad- ually decrease in size upward, all being wider than long, and almost flat. There are from .seven to eight bifurcations in each main division, or eighty to ninety arms to the species; they arc very much crowded, and rounded on the back near the cal^x ; upper parts unknown. Regular interradials eleven to thirteen in five or six range?, tho.se of the upper row quite snudl. Anal plate somewhat narrower than the radials, succeeded by fifteen or sixteen jdates. Ventral disk depressed above the rim, low-conical in the nii<ldle portions, the sides gradually passing into a large central tube. Plates of

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ACTINOCRINID.E.

035

tlie ilisk and tube quite irregular in form, size, and iirrimgeincnt, iiliuost as Hat as tiiosc of tho cup, and growing .smaller as they ajjproaeli the anus. Column apparently stout, the axial canal large ami peutangular. Ilurhon and Liwulitt/. — Upper Durlington limestone, Burlington, Iowa, Tifpe in the Museum of Comparative Zoology, Cambridge.

<*m

Teleiocrinus adoloscens AV nml Sr. (mov. .spoc). riuto UX. Fhj. 4.

('-) Syii. .4c/iiiorriiiiii jieiiii-il/a.< — .MtKK iiial WoiniiKX, 1871), CiLdl, licp. Illiiuiis, Vdl. V., p. 313, I'latc 8, i'ig. 2.

Intermediate between Cactocrinus and TcklocrinHs, but nearer the latter. Calyx moderately large, the height of the dorsal cup greater than the width at tho rim, the sides gradually rising to the top of the distichals, then curv- ing abruptly outward, forming a rim, whicli is somewhat interruj)ted at tho intcrradial spaces from the ])almars up. Plates thin and slightly convex, traversed by angular, well defined ridges passing from plate to plate, and forming numerous triangles. The ridges are single, except between the basals and ra<lials, wliich arc united by two or three. They meet at the middle of the plates in conspicuous tubercles, which are surrounded by several small nodes, placed within the corners of the triangles.

Basals of moderate size, their ridges thickened at the lower end, and formed into angular processes, which project downward and rest against the margins of the two upper stem joints. Radials larger than both costals together, as long as wide or a little longer ; the first costal hexagonal, the second generally somewhiit smaller and hoptagonal. Distichals as large as tho costals; both axillary, giving off from the outer side of the ray an arm, which is free from above the .second plate, and from the innor the second axillary. This is followed liy throe more axillaries, of which the two lower ones, respectively, support again an arm at one side, the upper two arms ; there being f[\c arms in each main division, .and ten to the ray. The brachials forming tho rim are sharply angular on tho back, and separated longitudinally l)_y deep grooves. Arms somewhat flattened, quite smooth on the outer faces, but their lateral margins slightly serrated. Kegidar inter- brachials : 1, 2, 2, 2, 1 ; tho upper very narrow, and sometimes touching the plates of tho tcgmon. Anal plate followed by 2, ,", 3, 3. and 2 plates. Inter- dlstichal areas wide and deeply depressed, occupied by two plates, longitudi-

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TIIK CUINOinKA CAMEUATA OK NUlM'Il A.MKKIC'A.

iiiilly luniiiged. Voiitriil disk baroly rising above the rim, iiiiJ doi'iily grooved interradiaiiy and interdislicliaily, tlio middle part conieal, passing inipL'refptiliiy into tiie anal tube. The tegnicn is composed of n large number of very small, sligbtly convex pieces, which enclose a lew larger, sharply nodose or subspinous plate", among which the orals and radial dome plates of a first and sicoiul order are readily recognized. Tube central, large and long, constructeil of irregularly arranged, transversely nodose plates. C'olunui slightly he.\angular ; the nxial canal large and pentangular.

//'//•/,;■'//; anti LurnUhi. — Lower Burlington limestone, Burlington, lown.

Tijitis in the collection of Wachsnuith and Springer.

Rfiaurl;^. — This species ditYcrs from all preceding ones in having a less number of aims, and deeper interradial sinuses at the rim, which are caused by a slight gap between the arms of adjoining rays.

The small specimen in the Museum of Comparative Zoologj', described and figured by Meek and Wortheii as Av(\nin-nim» jMiiicl/hiK, represents most probaMy a very young stage of this species. If, however, it is an adult form, wliicli we think doubtful, it is certainly not a IV/riucriiuis, for the branciies of the rays from above the distichals take the form of free arms, altlioiigh directed almost horizontally and crowded together as in that genus. We found also in our own collection two small specimens, evidently of the same species as the Cambridge one, and morphologically in the same con- dition. In one of them we removed the arms on one side, and exposed the tegmen and anal tube, so as to enable us to see the form of the cal^x. The length of the specimens to the tips of the arms does not exceed the heiniit of the conieal part of the dorsal cup in l\Icincrliius adnhiircns, which to the top of the arms must have been four times as largo as those speci- mens. The latter have but five interbrachials at the regular sides, and about eight above the anal plate, against eight and thirteen in the larger form. The arms to the fourth or fifth plate are nniserial, the joints long, cuiieate and zigzag, as usual in very young specimens. The tcgnien is conical, resembling the part which in the larger specimens lies inside the rim ; it is composed of comparatively few and large plates, most of them spiniferous, but there are no small plates interposed between them. Both forms have ten arms to the ray — exceptionally eight or nine — which hifur- ciite in the same manner. The proportions of the plates, and the surface onmmcntation as well, are also quite similar. So far as can be ascertained,

4

ACTINOCRIXin.T:.

68V

tlioro i.i notliing between the two forms tliiit couUl not be readily oxplaincil by individiml growtli, except the grciit contrnut in tiie >ii/,e of the Hpecinienn, wiiieii on tlie one hiiiul are (juite large, anil on the other very sinali, tlio intermediate forniM being wanting. Tlii.-* in part has led us to propose a new name for the larger form ; but the principal reason is that it is practically impossiljle to recognize the species, or even the genus, from Meek and Worthen's description,

««>

STROTOCRINUS M. and W.

1S08. yitr.K (111(1 WnicriiKV (iiicliuliiij,' 7; /,/.«■/■//;«-) ; (leul. Hep. Illimiis, Vol. II., p. 183, niid Proc. Ami.

Nut. ^^ci. riiilii., p. 'iJ'i, 1S73. /in'i;i. (iiicliuliiii,' Telriucriiiiia (mil l'lii/»i-lurriiiii>)\ lliiiidl). d. I'liliiMiit., Veil. I., p, 3"0. ISSl. W. 1111(1 Si'. ; Ui'visiuu Piiln'iKT., Pud II., p. l.-.s (I'cniTcd. Acml. Nut. Sfi. I'liilu., p. Wii). ISbO. S. A. Mii.i.Kii; Xortli Amur. iim\. iiud I'lihi'diil. p. iSil.

Syii. Ciiliillwrrittiif IIali, (Sidigcims of .ir/imeriiiiit), ISfil; (uul von Meyer ISIS, Bromi's Julir- bucli, p. K'p',)).

Strolocnniis holds the same relation toward Phi/Kctocrlnus that Tckio- criiiiis doe.'i toward Cnctncrinus ; the Hrst two being distinguished by having an anal opening within the disk, wiiile the last two have an anal tube. In the construction of the cidyx as far as the top of the distichals, all these forms differ only immaterially ; but from the palmars u]) in iSlrot"cr!nNs, ati in Tiktocrlnm, owing to the great increase in the number of arms, the brachials were crowded outwards and formed a broad, continuou.s, ten-rayed rim. in which not only the lower parts of the arms, but also the lower pin- nules, ))ocame incorporated. The specimens are of very largo size, and the ninnl)er of arms enormous, the di.sk sometimes attaining n width of 12 cm., with as many as fifteen bifurcations in each division, or one htmdrcd and fifty arms altogether. The arms are given off alternately from opposite sides, each order consisting of a single axillary plate, which .supports at one side an arm, a braciiial of a higher order at the other, and the uppermost one two rsi-ms. Tlie arms are thin and comparatively short. Intcrbrachials not .v.merous, and never extending beyond the palmars. Disk flat or very p'-'jlitly convex ; composed of thousands of minute, irregular plates, which decrease in size as they approach the arms. Anal opening excentric, rarely rising al)ove the general plane of the disk.

Dklrilmthu. — Restricted, so far as known, to the Upper Burlington lime- stone of the Jlississippi Valley.

Tjipc of the genus; Str"b>criivif^ rrr/n/is.

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Till:: CUINOIDE.V CAMLUAT.V OF KUUTII AMKltlC.V.

licmarkn. — Wo cannot pliico Stru/ucn'mts and Tikiocrinus together in tlio same genus, us was done hy Meek and Wortlien, I'or they evidently have a dilToieiit origin, tiie former being develojjed from J'/ii/sit(irriii((s, tlic latter from Cuclucrinas. Tiie nioclilieation^ tliai toolt place in the two I'oiins were in the name direction, and this accounts for the resemblance which unijucs- tionably exists between them. A \'ery interesting feature of this genus, which has not i)een observed in Ti/uDcriinix, is the incorporation of the lower pinnules, the plates of which lake the form and cilice of iuterbrachial and interdistichal plates.

StrotocrinuB regalis Mam.. Piak LXV. Fi</s. J, I. I., r, </.

I'lOO. J:'finorri>iiis rfi;ii/ii — IIm.i.; Sii|i|i| (ii'dl. l{i'|i. Inwii, p. '.I.

ISim. *,•.,/,„•/■///«» m/,///. — . Ml. KK nil,! W.mrin.N; (Icul. l(.'|i. Illinni^ Vol. II., p. IflO.

1873. Slrofiirriiiiin pfrHiiil,fu<ai — .Mkkk ami Woutmkx; Ciidl. Urp. Illliiciis, Vdl. V., p. ;i,i7, I'Inte 8,

FiR. ■!. 13^1. SUului-riiiiis rr;/ii/i.< — \\'. ntul Sr. ; Hcvisinii I'mIickt., rail II.. p. 100.

Syn. .Icliiinfrhiiif ii''niiiiljrnHii.i — IlM.t.; ISCjO. Siippl finil, Hi'p. Imva, p. 7- S,vn. Jr/iiiitrriiiiif A/m-iiitiif .\Ikkk ami Wuktiikn; ISilM, I'mcci'd. Arail. Nat. Sci. I'liiln , p. HSO i>\i\. SfrohrriiiHi ilijuiu/ii'/'/fiinif S. A. Mil.l.tK; l*'?'.'. .Iimni. Ciiiciii. Scio, Nat. llisl., riatc li, I'iR. 0.

An extremely large species, the calyx across the rim to the last bifur- cation reaching sometimes a diameter of 12 cm., and a height from the foot of the basals to the base of the rim of 5| cm., and to the tips of the arms about lo cm. Dorsal cup urn-shoped, the sides a little convex ; the disticlials bending abruptly outward, and forming the base of the rim, which t^lojjes a little upwaril. Tegmen almost flat, often depressed in the middle. Plates of the cup convex, covered with strong, angular ridges, which rarely meet in the centre of the plates, but run to a place near the centre, where they leave a small central depression or bare spot ; sometimes, however, the middle space is occupied by a small transverse node. The ridges are in parallel sets of from three to six; there are five to six between the radials and basals, and from two to three between the other plates. The surface of the brachials in the rim is sharply elevated into angular, longitudinal, zigzag ridge.s, which distinctly mark the lines of bifurcation, and leave between them broad .shallow grooves, which are paved at the bottom by tlie plates of the fixed pinnules.

Ba.sals very large, forming a deep cup, the sides of the plates beveled,

ACTINOCUIXID.K,

639

t

fDi'iniiig kIuiIIow gi'oovi'M iilimjj; tliu .siituri'H, wliii'li iire in iiiiuiy HpcciineiM iiiilistinct or coiicoiik'd from view hy tlio largo mllii'rt'iit uppiT stoiii jdiiit, liiiiliiils and luial [)liito wvy liu;,a'. goiionilly loiigcr tlmii wide, their latcnil faecM iiiuc'h larj^er than tliu othors. First (.'ostais ul' tin; same form as ihi' railials, l)ut a third Mnialler; the second a littlo Hliorter tlian liii' fu^t. Suc- cuudiiiy brachials to the margin of the rim ahont as long as wide, gradually decri'asing njiward, L'tuih ont' sn|i|)ortiiig an arm fioin one xido, and an axil- lary of iiighi-r rank from the other — except the upper one, which Nupporl.s two arms — the lower arm plates and their pinnules taking part in the rim. The arms from the distichals nro incorporated to the sixth plate, those from the jialmars to the fifth, and so on to the last hifincation ; the arms of the former being given olt toward the outer sides of the rays, those of the latter to the inner; the Hrst pinnule of each arm proceeds from the proxinuil plate. There are fourteen bifurcations in each nuiin division of the ray, with as many a.s fifteen arms, or thirty to the ray, and one hundred and fifty to the npecies. But from the eighth bifurcation upwards the arms arc semi-free — oidy the proximal plate of each arm being attached — and thus are in a similar con- dition to the arms of S/ci/iiiinrriiiiis (I'late LX\', Fig. If/). The free arms are short, simple, and biserial. Interbrachials: 1, 2, 2, 2, 2, 1 at the four regular sides, and 2, 3, 3, .3. 2, 1 at the anal interradius ; the two upper rows forming part of the rim, being arched by the i)latcs of the fixed pinnules of adjoining rays. The interdistichals consist of only one plate, which is arched by pinnules. Ventral disk covered by many thousands of .small irregular pieces, which decrease in size as thoy approach the arms ; those occupying the middle portions almost (lat, those near the outer margins slightly nodose. Anus .subcentral, small, the opening directed anteriorly. C'olmnn large, round ; the nodal joints but little wider than the intervening ones, their edges covered with a row of small nodes.

Horizon ami Loculil//. — Upper BiuTington limestone; Burlington, Iowa, Quincy, Bis., Hannibal, Mo., etc.

TijiK in the (Worthen) Blinois State collection, Springfield.

ItrniarliK. — We obtained at Burlington a very larg(> specimen of this species, which with stein and portions of the root measures about two feet in length; the width of tho stem near the calyx is 8 mm.; its greatest width, about five inches from the lower end, 12 mm.; tho width of the branchlots, 5 mm. From the first brancldet, which is followed in tho specimen by nine or ten others of nearly the same width, it tapers gradually to G mm., from

U

/I

GIO

TIIK CHINOIDKA ( V.MKHATA OK NO« III AMKHICA.

wliiuli wo iiifur tliu ruol vum prulxibl^ I'luiii Idiii' (o livu iiicliuH lungor. Tliu hniiielilutt ai'o iin'j,'iiluily arniiigi'il j tlu'^ wore aiipiiiviitly (luilu long, as onu of lliuiii, wliicli in luowervtil to llio luiigtii ol J cm., iftaiiw its lull ihuk- nuMri to tliu ciiil.

The nuinbor of nriiis j)iol)al)ly vnricH from twoiity-lour to thirty to tl u ray. Tlio latti-r mimlior ooi'iirM in two of our largest HpfcimouH, wliilo a snuiller onu in the M, C. Z., which Meek and Worlhcn iik'ntilioil a.s SlrolD- o'iniin jiauiiibiufiii.s Hall, lum but twi'Uty-livc.

StrotocriuiiB gljrptua llu.i.. Pint, LX Fhju. lit, b, r, mi,/ J'lal, /.AT. /'/V/.s-. 3(, h.

I860. .Irtiiiueriiiiit ///j/pfiit — \\.\i.\. : .Sii|i|il. (IcdI. llip InHii, p. i.

1S<I. N/nluiriiiHt ffly/iht ~ W. iiiid Si', ; Ucvininii I'lilirucr., I'lirl 11., |i IfiO.

A little Hinallor than tlio itn'ouding cpcoicM, ihf cup comparatively siiorter, ami the tegnirii convex instead of llat. Caly.x ohcouical to the top of the di.stichals, then bending aliruptly outwnid and forming •■ decangular riui at right angles to tlie axis of the calyx; liei;;lit to width at the rim at* two to three. Plates convex, covered with radiating ridges, meeting nt a small node in the centre, and conunuincaliug with the riilges from adjoin- ing plates. Toward the basal.s there are foiu' ridges from each nntero-lateral iadi:d and the anal plate, and three from the anterior and two posterior radials; while there is but one between the other plates. Zigzag ridges, as in .S. nyitlifi. formed by an angular longitudinal elevation on the brachials in the rim, follow the lines of bifurcation, and leave angular dcprossioirs between.

Basal cup twice as wide ns high, the sides almost vertical ; grooved along the sutures; a.\ial canal moilerately large and pentangular. Radials as wide a.s long, and nearly as large ns both costals together. First costaln hexagonal, the second heptagonal, shorter than the first. The brachials of the succeeding orders ns long as wide, slightly decreasing in size up- wards, each one supporting at one side an arm. of which the lower plates are incorporated into the rim, nt the other a brnchial of higher rnnk, and each arm giving ofTpinnides whoso proximal joints also take part in the rim. The arms proceeding from the distichals nro free above the fifth plate, those of the palmnrs from the fourth. There are eight bifurcations in this species, giving origin to nine arms from the main branches, and eighteen from the

ACriNUCKIXID.K.

m

'•

iiiy«. AiiiiH poniimi'iitivoly (tliort, mill ruthor dolicnto ; nll^'litly (liitltMcd ut till' MiipiT oiiiIh, Hi'guliir iiiti'ilniu'liial.t : I, 2, 2, rollownl liy 'J niul I |«lattt within tlio rim; tho liittor piucu urclied ovur by tho pluti'i oi tlio proviiiml |)iiiniiIt>N of till' proxiiiiiil ariiiM in a(1j<iii)in^ rnyx ; tlio ami I intcriailiiiM ciiii' »\My* of 2, '.], I. ■_' ami 2 plafi's. IiitiTilixtieiiiils onu, roofed t)y tlic incoipor- iitcil lowor pinimlfs of tho Mccond arm. Ti'gmuii r'wug luit .xlighlly at tlio top of tho rim, tho inidillo portion low dome Hliupod ; tlu> platod very niimeroiiM, irn'^iijarly arranged, nearly Hat, jfrndiially docroasing in hI/o toward tho arm hanpH. Ahum xiihcontrnl, at tho top of a small profiilMTancc.

/fiiri:iiii mill Linilif//. — Tppor Ilurlington liiiicMtono ; Burlington, Iowa, and at Novoral placoM in Miswmri.

Ti/jie in tho (Worthcn) Illinois State collection.

lii'iiKirkit. — Thi.M spocios dilTorN iVoni tho preceding one in the mnallor ni/e, tho HhortnoHH of tho calyx, tho Iocs number of arum, and in the conve.xity of the vontral disk.

i

It

V

II

i

n

PLATYCRTNTD.E Roemer.

Mo.NOCyCLIC. BUACHIALS AND INTKRBRACIIIAL3 ONLY SLIGHTLY REPRESENTED IN THE DORSAL CUP; THE LOWER BRACHIALS TAKING MORE OK LESS THE FORM OF FREE ARM PLATES; THE LOWER INTEHUADIALS IN PART INTEKAMHULACRAL IN POSITION, RARELY ENTIRELY INTERnRACHIAL. KaDIALS IN CONTACT ALL AROUND, THERE BEIN(r NO SPECIAL ANAL PLATE. JJaSALS FORMING A PENTAGON.

i^i !

Analysis of the Genera. Baaals 3, unequal, frequently ancbyloaed.

A. COSTALS TWO.

1. Column eircii/di:

a. Dial; almost completely occupied by the oni/s ; rimliulacra subtegminal ; omls separated from riidiii/s by only one rill;/ if interradlaJs. Orals symmetric ; arms ,a|)parent,ly dolicato . . . Coeeorrinus.

Orals asymmetric ; .arms heavy, biserial .... Cu/ieocrinus.

h. Dish composed if numerous jilntes ; orals uot oliserved ;

arms uniserial, or sliijhtly interloehinij Cordylocrinus.

B. CosTALS ONK.

1. Orals oeeupyini) but a small part of the dish, and asymmetri- eully arranged; ambulacra exposed ; arms biserial.

a. Column circular; canal large, i/uimjueloljate ; distichals

one when more than one bifu rent ion ^farsuJ)il)erinus.

b. Column ellijifir ; canal small, round ; distichals two.

Arms bi-aiiehins by riltcriiate bifurcation .... I'latyerinus.

Rays extended into t",lmlar appendages giving off

tiie arms Eucladocrinus.

-

I'LATYCRINID^i:.

643

e/V

a 3

d

2 H

Geological and Geographical Distribution. Number of known species.

(Opcu figures iiuliciitc American ; those iimrkid ( ), European).

FOKMATION.

American.

St. Louis.

Warsaw.

Keokuk.

Upper Burlington.

Lower Hurlington.

Kinderhook.

Waverly.

Clioutcau.

Hamilton.

Lower Ilelderberg.

Niagara.

Total species

O)

Wj

<v

H

(^3 3

i3S

b c

Eifol

ri.ATycRINIll.«.

Grauwacke.

Wenlock. Gotland.

108

( 7." 1(3'

15)

(1)

(1)

(1)

1

(I)

o

(2)

2

o

11

-(20)-

28

W

3 {',)

4

10

f.0

(20)

'J

1 s

1)1

'■ i

644

THE CRINOIDEA CAMERATA OF NORTH AMERICA.

D.C.

Dorsal cup.

y.jj.

A'ciitrul ilisk.

b.

basnls.

R.

I'lidials.

I.

post Ills.

ir.

iiitcrmiliiils (in part intcTl)racliinl, in

part iiitorambiilacriil).

ut.

iiitcrainlmlacrals of llie regular sides

x.r.

iiitcrambiilacrnls of aual side.

u.

orals

>■/>■

covering plates.

i I

Bcmarh.—lhe Platycriiiicloe are the typical family of a sub-group which is distiuguiisiiod from all other i'amilie.s of the Camerata by having the brach- ials anil intorbrachials only slightly represented in the dorsal cup. The lower brachials, although incorporated into the calyx, belong in part to tlie cup and in part to the disk, and have more or le.<s the form of free arm plates. From tliis we conclude that the Platycrinida; represent phylogenct- ically a less developed stage of the Camerate Crinoid, in which the lower arm plates remained in an immature condition, their small size giving rise to the interposition of three plates to fill up the interradial space in the first row, instead of the usual single one. The lower interradials, therefore, are for tlie mJtst part neither strictly interbrachial nor interambulacral, but may be considered as belonging to both. Tliis is not invariably the case, however. In a remarkable undescribed species of Plati/crinus from the Mountain lime- stone of England, the costal and the two distichals are connected with those of adjoining rays by five or six heavy plates, which are strictly interbrachial

% i

PLATYCUINID^E.

64;

^^

in position ; and a similar structure, in a loss degreo, is to be observed in a few American species.

The above general character of this family is shared with it by the Ilcxa- crinidtc, which were placed in the same family by all writers on Crinoids up to 1885, when we separated them. The two groups, though more closely related to each other than to any other family, are nevertheless readily dis- tinguished by the form of the base, depending upon the presence or ab.sonco of an anal plate within the ring of radials. The Platycrinidas have no such anal plate, the radials being in contact at all sides. The base is therefore a pentagon, and is com[)osed invariably of three unequal plates, the sutures between them being always directed to the right posterior, anterior, and left antero-lateral radials. The interbasal sutures are, however, very often anchy- losed and invisible from the exterior. The Hexacrinidas, on the other hand, have a large anal plate interpo.sed between the two jiosterior radials, resting by its full width npon the edge of the basal cup ; they consequently have a hexagonal base, which in that family consists either of two or three equal plates.

The Platycriuidio embrace six genera, of which about one hundred and eight species have been identified: — eeventy-three in America and thirty- live in Europe. Although introduced in the upper Silurian, the family was not prolific in forms until the age of the Subcarboniferous, when, especially in the Lower Burlington limestone, and in their typical genus, Plal^cnnns, they reached their climax ; — abounding in number and variety, and in beaut}' almost surpassing the Crinoids of any other group.

The modifications which took place in the course of time among the Piatycrinidic ar-) very slight ; and in fact the young ConIi//'icrmiis from the Niagara, with its uniserial, sometimes zigzag arms, which it retains during life, resembles most remarkably the immature P/atijcriinis of the Sidjcarboni- ferous. Coayicrinus and Ciillcocrimis also represent stages of the growing PlatijcrhiHS ; both have unusually large orals, which in the former are .sjinuK'tric, in the latter asj-mmetric, and there is but a single row of in- terradial plates between orals and radials. The ease of j)/i(rsiq)iiirnni(s is .somewhat different ; it has small asymmetrical orals occupying the centre of the disk, numerous ambulacral and iutorambulacral plates, and highly developed biserial arms. The genus has all the characteristics of a mature Platyerinoid except that it has the round stem of the young rjnti/crimis, but with a large qtdnquelobate canal ; these are in fact the only characters upon

i1(

-!j

»'

Hi,

m%

I

"liWiNi

(

04G

THE CUIXOIDKA CAMKUATA OF NORTH AXIKUICA.

which the two gt'iiera ciin be separated in tiie fossil state. Eiwhuhcnmts is an extravagantly developed Phi t^cr inns, and should perhaps be regarded ns a subgenus.

Coccucriiius was placed by Mliller and Roenior among the Platycrinidoe ; by Pictet, Dujardin and Ilupe, Zittel, and S. A. Miller, under the Ilaplo- crinidao; while at the same tine the latter authors refer the clo.sely allied Cnlicocrmiis to the Phitycrinidio. which according to our classification would place the one among the Larviformia and the other among the Camcrata. We do not see how this can possibly be the case ; we believe that Cocco- criniis is a true Camerate Crinoid, which passed the Larviformia stage in early life on the introduction of perisoinic plates. The genus holds a similar re- lation morphologically toward Platycrinm to that of the recent genus IIolo- pus toward JJi/ocnmis, whose orals have been carried inward by increased perisome.

In Part II. of the Revision we referred the doubtful genus Colykdono- criniis to the Platycrinida\ but have since found it to be identical with Dlchocriims.

In descriptions of the PlatycrinidiE and Ilexacrinida? we sometimes use the term " interradials " for the lowest plates between the rays, because, as already stated, they are neither exclusively interbrachial nor interambulacrol, but partake of the character of both ; that is, the same plate often belongs partly to the dorsal cup and partly to the legmen.

•■

h.l

I

T

J^

I i

I

PLATYCHINID^E. 647

PLATYORINUS Milleii.

1321. Platycriiiiica — Milleu; A History of the Criuoidca, p. ?!•

lS31i. " (iii |iiirl) — OoLDnsSj IVImfuct. (Icr Vol. I, p. 188.

1835. " (ill imrt) — AiiAssiz; ili'in. Soc. Niuclmt., Vol. 1., \i, 1U7.

1831). Pl(i/^criiiHii — Vnu.\Ai's; Gcoloyy of Vorlishiic, Vol. II., p. 2Ui.

1S39. P!,i/i/friiii/i'.i (in purl) — (JoLDnss; Nov. Actii Ac. Luiip., Vol. XIX., p. 313.

1S41. PlKti/ci-iiim (ill purl) — Joll. MClleu; Muimtsbcr. liurl. Akiiil., p. 207.

18i2. " —'I'. ArsTiN; Aim. nml Miig. Nut. llisl., Vol. \ , p. ID'J.

1843. " — 'r. ArsTiN; Moiiogr. Ucc. nml Fo.s». C'riiioiils, p. li.

1841. " — McCov, Syu. Curb. Liiiicsl. Foss. Ircliiiiil (cil. 2). p. 175.

1858. " — U'OuiiKiNv; Cours i'li';iuciil. ili' rnluont., Vd. II., p. 112.

1853. " — PeKon. imil I,e IIo.m ; Ki'dicicli. (,'riii. lid).'., p. 155.

1855. " (ill pari) — F. HoKMEii; l.ttliii'ii Cicofiii. (.Viis;;. 3), p. 212.

1857. " - I'UTET ; Tiiiile ilu I'lileont., Vol. IV., p. 330.

1858. " —Hall ; Ciuol. Hep. lown. Vol. I., I'nrt II., p. 525.

1863, " — Duj.iRiM.N' mill IUte; Hist, iiiilur. dcs Zoopli. Fcliiii., p. 151.

1870. " — ZiTTEi,; Himdl). il. I'lilii'ont., Vol. I., p. 3111.

1881. " — W. mill Sr. ; liivisioii I'lilu'ocr., I'lirt 11., p. (15 (rnriTd. Acid. Nut. Scl. riiiln., p.

230). anil liltO, I'rocml. I'hila. Aiviil., pp. 351-353. 18S5. " — QuEXSTKiiT, lliiiidb. dor rcliTl'ai'Icnkiiiidi' (Aus),'. 3), p. 951.

1859. " — S. A. Mit.i.KU; \. A. ficol. nml I'ldn'oiit.. p. 271). Not Pilil.i.M's, ISU ; I'lilii'oz. Fuss. Cormnill, p. 2S =: /A'.f«cn««.t. Not F. liciEMEU, ISU; lilicin. Ui't)Prp;niif;sg., p. (13 =; <'(,m,i;-iiiiis.

Not D'OiiliTuxv, l'<50; I'rodri'inc do I'lilroiit., I., p. \<l'.i=^ .Uiim/pioi-ri>iu>.

Not ll.vi.i., 1801 ; raliiMint. X. York, Vol. III., pp. 113-117 = Cunli/lurriiiiis imd iLirsupiucriuits.

Not SciiuI.ZE, 18(11); Fi'liinoil. Kill. Kalk., ]i. (Is = .Sy«/7///*/i«virf(H.

Not I.VON, 1809; Amor. I'liilos. Sue. Vol. XIII., p. 159 = //m/cW««.».

Svn. Aatropotliti Uhe, 1893, Hist, of Knlliriiilin.

Syn. A'l/ce liiicriiii/e I'.iUKix.so.v, ISU ; Oii;. Hriii., Vol. II.

Syn. Fnrriiiiteit (\\\ part) Scnr.oTiiEiM, 1*^23; Niioltlr. ziir I't'tri'fadonkiindo.

Syn. Ci'iilrocriniis anA Plfiiroeriniis Ai'.sTix, 1813; .Moiiugr. Criiioids, p. 0.

Syn. Eilwiirdsoeriims D'OiinKixy, 1S50, I'roilroini', Vol. 1., p. 150.

Ciilyx oblong, globose or iiyramidiil ; tlio dor.«al cup conical, bowl-sliapeJ, or (ILscoid. Basals three, large ; two of them equal and twice a.s largo as the third ; the latter rhoniboidal and placed with it.s upper angle between the anterior and the left antero-lateral radial.s; the plates so clo.sely anchylosed that they cannot be .separated, often not leaving even a trace of the suture line. Radials very large ; their upper faces partly excavated, and forming a well defined facet for the reception of the brachials ; the limbs to both sides of the facets more or less sloping, forming notches which support the interradiiil plates. Costals one, exceptionally two,* united with the radials by an almost rigid suture, the plate being often so small as to be buried within the facets, so that the distichals touch the radials by their outer

* p. Iriinnitiiliis from the Lower Burlington limestone, and P. ericiisis from the Hamilton group, have two well duliued costals iu every ray.

• I.

ill

hi'

-*

I

ll'l

M

648

TIIK tUINOIDKA CAMKRATA OF NORTH AMKRICA.

margins. Tlic distiulmls, and nil the higher orders of briichiiils to the last bifurcation, gi'neially consist of two plates each,* of which the upper one is axillary. Tiiese plates have the form of free arm plates, being rounded on the back, but the lower ones are suturally connected with the plates of the disk, and in some Hi)ecies also with the radials, or with their fellows of the opposite side of the vay, and are tlari'fore rigid. The rays divide above the costals into two branches, which bifurcate independently, the axillnries of both branches I)caring an arm upon one side, : 'id the next order of brachials upon the opposite side, the last axillary supporting two arms. Pimiides strong, the first pimiule given off in some species from the first distichal, in others from the proximal arm plate.

A'entral disk pyramidal, coiivex, or almost flat. Orals slightly exccntric, and more or less a.symmetrical. Andjulacra composed of two scries of cover- ing pieces, which are expo.sed upon the disk. The interambulacral plates variable in number, except the first row, which in part is intcrbrachial, and always consists of three plates transversely arranged. The middle one of tiiese plates is larger than the two at the sides, which are elongate and bend outward to form the nmbulacral passage. Tiie upper ends of the side plates rest against the covering-pieces of the ambulacra, the lower ends against the sides of the costals or distichals, as the case may be, and sometimes against tlie palniars. The anal side has also three plates in the first row, of which, as a rule, the middle one is widest and gomctimos highv r than the corre- sponding plates of the regular sides; these are followed by numerous small plates. Anus exccntric, either opening out directly through the disk, or located at the top of a protuberance, sometimes at the end of a tube.

Column of moderate length, the lower end giving off rootlets at irregular intervals ; the joints elliptic and twisted, the twist being imparted to the wliole stem, permitting motion in all directions. The articulation between the joints bifascial, there being a well defined ridge following the long diameter of the joints. Axial canal very .small.

Dis/rlhutioii. — This genus constitutes one of the leading fossils of the Subcarboniferous on both sides of the Atlantic. It made its appearance in the Hamilton group, and became extinct in the St. Louis, reaching its climax in the Lower Burlington limestone, from which horizon we recognize twenty-eight species, not counting the numerous synonyms.

• In P. iiiroiiip/itf, and some ollicrs, roprrscntiiiK n Irnnsilioii toward Euctadocrinut, tlie orders of brachials above tlic i)aliiiars consist of Uirec successive platea.

% \

PLATYCIilXID.K.

c-to

Type of the goiuis: r/nli/criiiiis herln Miller.

liemarkii. — Wo have iiichiiled under riatijcrlmis species with nn anal tube, as well as those in which the anus opens directly through the disk. A tube, such as was represented by the Austins, and by de Koiiiuck and Lu Hon, extending almost to tlie tips of the arms, 1ms only been observed among American species in P. cxcaca/iis. Most of them have an exccntric, miinunirorm protuberance with a small opeuir.g in the middle. The longest tube except the above which we liave found is that of 1'. Itirlliiijtimiiisis ; it rises but a few millimetres above I'le general level of the disk, and has a small opening at the end, while the end of the tube in .«ome of the European species is closed, roun<led olT, and, according to Austin, valvate.

The Austins made an unsuccessful attemi)t tu subdivide the genus ujion the structure of the anus. Under riutijrriiiHx, they proposed to place the species with "a central elongated oral tube." For species with a "central valvate, unobtrusive mouth, or mouth capable of being withdrawn into the visceral cup," they proposed the name " Ccntmrriiius" and " rUurocrimts" for those in which the mouth is " [jlaced laterally, or not central." Some of these ideas are altogether fanciful. The so-called " mouth," for which these authors mistook the anus, is always excentric ; and a withdrawal of the anus into the body, as they imagined, is incompatible with the construction of the ventral side of Camerate Crinoids as now unilerstood. Neither of the pro- posed names has been applied to any of the species, not even by the Austins ; and it seems to us that, for the present at least, any general division bused upon the structure of the disk and anus, is not practicable in a group in wiiich the parts in question are but rarely observed.

In default of any other characters upon which a generic division coidd be established, we have arranged the species into groups, in accordance with certain specific peculiarities, iioping thereby to assist the student in the identification of the species.

Of the one hundred and twenty sjiecies of PJati/crmus described from America, wo recognize but sixty. Many are unquestionably .synonyms. Others were made from such imperfect material, or so insufTiciently de- .seribed, that their identification is ab.solutoly impossible. The outcome may be somewhat unsatisfactory, but it is the result of careful study and impartial consideration, and if we have erred in this respect it is probably in not carrying the process of elimination far enough. It may not be out of place to state that we devoted a long time to the revision of Plati/crlnus, and

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660

THE CUINOIDEA CAMERATA OK NORTH AMERICA.

were enabled, through the liberality of our Anioricnn Museums and collec- tors, to make direct comparison with the types of almost every species, except some of those described by S, A. Miller, and Hall's Richfield speci- mens in the New York State Cabinet.

The eleven groups into which wo arrange the species are based variously upon the style of ornamentation, the general furm of the calyx, the details of the arm structure, and other characters, none of which can be regarded as of generic importance. Some of these groups are apparently unrepresented in Europe. None of the European species known to us are referable to the Discoideus group, nor to the Subspinulosus, Sarre, or Truncatulus groups. The European .species, as a rule, are coarser in their ornamentation, the slope of the cup more abrupt, the plates heavier, the suture lines and rugosi- ties of the plates deeper, the nodes stronger, the ventral di.sk higher, and often surmounted by a large nnal tube, somewhat resembling tliat of Actlnocrinus and IJu/ocrinus. The facets upon the radials also, as a rule, are deeper, and are frequently provided with a transverse ridge, indicating that the union with the brachials was not very rigid.

We have rejected the following species as unrecognizable on account of insufficient preservation, or inadequate description.

/'. uhseiilicm S. A. )[ili,er, Clioutcim group, Si'dnlin, Xto.

P. (iiiKil/ilin S. A. MjLi.Eit, Burliiii,'li)ii grciuj) (?), Lnc (?).

P. iiniiiisiix S. A. Mii.i.KU, Choulcnii group, Snliili.i, Mn.

P. uUiilnrxdIiis Udwi.KV ami Hake, Upper llnrlini;li)n limestone, Louisinna, Mo.

P. b'':l/iiril'iiu.t Uai.i, iiml Wiiirr., ^Vuvcrly group, Bedforil, Ohio.

P. Jitiiiri S. A. Mii.i.F.n, Biirliuglou group, Scdiiliii, Mo.

P. ciil;/rutm Ham., liurliiiglou group, Hurlinglon, Iowa.

P. clniKlraueiisia S. A. .MlI.i.Kll, Clioulciiu group, Si'dalin, AIo.

P. Culli-lli S. A. Mii.i.EH, Chouteiiu group, Scdidiii, Mo.

P. coiici/111113 S. A. MiLi.EU, Uurliiiglou group, Si'didia.

/'. ebonieeus Ham,, Hamilton group, Livingston Co., N. Y.

P. Iliit/ilrni Meek, Subcnrboniferous, Montana.

P. murijiniilus UoWL. and Haiie, Upper Burlington group, Pike Co., Mo.

/'. priildf/onus S. A. Miller, Keokuk group, Boonvillc, Mo.

P. iiliiiiu-biisalis RowL. and Haiie, Upper Burlington liincstouc, near Currjville, Mo.

7'. pumiliis Hall, Warsaw limcslom', A\'arsaw, Ills.

P. texabilis Weiite, Subcarboniferons, Nevada.

The following species we consider to be synonyms: —

P. ttleriinlh S. A. MlLLEB = /'. bonoensis AVllITE.

P. alabamensi.1 S. A. Miller = /'. //uii/tril/,e Troost.

P. batiolii S. A. Milleu:=7'. irqnalis Hall.

P. blooiiijii'hlensis S. A. Mii.LEii = P. planus 0. and SiiCM

P. ProiitlheiHli S. A. MlLLEIi = P. aiiicricami.r 0. and SlI.

P. ratluciix S. .\. MiLLEB= P. bniiiieiiais White.

P. carcliesium S. A. Miller = P. inleifiriiiis Hall.

..^!

I'LATYCRINID.i:.

661

P. elytii Ham.ss /', tco/iinii Mkkk niiil \V.

P. coirui/dlus O. iiiul Siii'M. ^ /'. ilh,-'iiilei(ii O. nnd SiifSi.

P. ciinyi-ilk/ivi UiJH'i,. unci II.VIIK = /'. uijiiili'mm S. A. MlLLEH.

P. ejrai'i-liiD I1ai.i.= /'. Iiiirliiintuiiriiiia (), nml Siiiii.

P. Oeori/fi 1Iaix = /'. S<ir,r lUl.I,.

P. riiiijirlilniaia Hai.i, uiul \ViHTfiKi.ii = /'. grniiliicus II. nud W.

P. inuftnitux MrClt. == /*, itifHuiilutU'iim O. iiiiil Sh.

P, liiuhin S. A. M11.1.KI1 := /'. 1/urliiiiflitiii'ii.Ha O. mill Sil.

/'. mu/ir(>i'ii.ils WiiKi'iiKN = /'. Siirrr Hai.i,.

/*. muttibritrliiatu^ M. and \V. == /'. 'fi^i'uii/fn.f 0. nml Sit,

P. uiiiliilini,'liii(/ii.i Hai.i, ISOl (iint 1S.")S) = /'. I'dm/illi, vat. permper.

P, iiui/mi4.i WlliKiKN imd 'ihllXU — Ciilii'furriiiiis iimhtim.

P. iiu,l(,lii-iii-lii,ilii.i Hai.i, 1S.')S (ikiI 1801) = /'. Imrliiii/linieiifis 0. nnd Sii.

P. iimliiluaiif Hai.i, (not (iiii.np.) ^ V. ariiiijrttiiulm .McC'il.

P, niH-li'iftfiiiin Hai.i,= /'. bHtHiiijiuiii-nxis (), nnd Sii.

P. oil,, Hai.i, ImU (imt DkK. nnd I,k. Hon 1833) = P. Ilidli Siiusi.

P. Oirnii .\I. nnd \V. = /'. y,y„/l.i Hai.i,.

y. /iiiri'ii' Hai.i. = (-'iinlj/nrii/iiif ///«/««.««.» (Hai.i.).

P. /iciiirilliix M. nnd \V. = /'. Iliiiilxi'ill,r Tikhlst.

P. jitiiiKj-lMwlh Udwi.. nnd Hahk = /'. (/iiiin/iieriuiliit WllITE.

P. jilioii,) Hai.i. (nut (). nnd Sii. Is.i:!) = /'. //«//j' SiiuM.

P, jilfnitt M. nnd \V. = /'. Ihiithfilt'C TnoosT.

P. jileiiruriiiiiiiiit WiiiTK = Kiiclii:tuCi-i,iiia /ilriiruriiiiiiifH).

J', /ihiuiiivis Hai.i,= Ciirdi/lnrri/iii' /iliiiiiMiit (Hali,).

P. iir;rntittiirun Hai.i, = M/irxftpiiirriiiii.i iiftrhiutunis.

P. jjr,ruuiifinf W. nnil Si'. = /■iiif/i/ilocriiiii.i jii'iriiuiiliiis.

P. Iinitleniiiiiin .\I. nnd \V. = /'. Surir Hai.i..

P. imli'hfllax S. A. Jlii.i.KU = /'. (tisoiiih'ii.i O. nnd Sii.

P, riimidutiis Hai.i. = Coi'ili/lorn'/mi niuiiilusu.^,

P. rtiftiii'lim S. .\. Mii,i.Kii=. /'. si'iil/i/im Hai.i,.

P. fili'/niiiriliifiu/^ Hai.i. = /*. ilisniiftru^ O, nnd Sii.

P. ali-iutii'iit'liiiilim Hai.i. =: /'. itixroiiliiif 0. nnd Su.

P. siiU-(ilii> ^'. A. .\[ii.i.Kii = = P. iwcMiiluf Hai.i..

P. Iniiiem'nmx Ww.wv.w^ytiiniiiiinrriims tennefseemii.

P. tfnttlflflilliia \l.\\.\.=: MilrHif/tiui-fiiln.t tt'dlttriililtus,

P. tninriihin Hai.i. = /*. ttmpriiunnis O. nnd Sii.

P. Iiiherosm lUl.I, = Eurluilooriiim liiberusus.

Of the seventeen .ipocle.s in the above list which we have been unable to identify, the majority were described either from the basal.s alone, or these witii tlie addition of the radials, and most of them from a .single specimen, — a practice which cannot be 'oo severely condemned. No pal»ontolog-ist nt tiie present day would undertake to describe an Actlnocrlnm or Butocrinm from n specimen showing nothing but basals and radials ; and why should it be done with Phitijm'nii.s? There is often the greatest difficulty in defining the limits of species and varieties with an abundance of the best preserved specimens in hand. The variation of surface ornamentation in Platycrlnm is almost without limit. The detached radials and basal plates, beautifully preserved and free from matrix, have been collected by thousands from the soft sandy layers of the Lower Burlington limestone, and it would be possible

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TIIK CUIXOIDKA CAMKUATA Ol" XOlMIl A.MKllIC A.

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to pick out «ovoral scoro of tliein, wliowo surfiieo nmrkings woiiltl in no two bo exiiutly aiiku, anil wliicli inigiit in Hufliciuntly onurgetie IiiukIm bu nuulo into ns niiiny siR'cicH. Among tiie Ninooth Hpecies of tho llmiington group tlioru (tiv scvenil Ibrnis, which it is absolutely impossible to scpunUc from tlio slmpi! ;iiiil pioportions of the dorsal cup alone. Tho arm structure indi- cates that tiiiMe is more than one species, but unless the nrnia arc attached the l)ost Crinoiogist cannot identify tiicm. Even the nundu'r of arms, upon which great stress has been laid by some autiiors, cannot always bo depended npon iniless associated with other ciiaracters. Specimens of the same species may have four to six arms in one ray, and only two or three in an- other. Exceptions to the general rule arc nowhere more frcfjucnt than in Plati/rrlttHS.

All attempts at de.scriljing new species will be worse than useless if made without at least some reference to tho ontogeny of the Crinoids generally, and of tho particular group in hand. The modifications due to individual growth in P/ah/criiiiis are particularly well known, and are very striking. In the mature specimen the ba.sal cup is proportionally deeper; the radials more elongate ; tho stem joints, which are circular in the young, become elliptic ; the arms gradually change from imiserial to biserial, and from zig- zag to nearly straight; the arm joints are proportionally much longer in tho young than in the adult; the ))innule8 much stouter and further apart; and the orals grow relatively smaller as they arc carried inward by increas- ing perisome. Unless all the.se matters are taken into consideration, tho describing of species amounts to little more than description of individual specimens. This in many cases is not without value in bringing to the knowledge of others a really new form, but when carried to excess it is the terror of the systematist who has to overhaul the work. Neverthe- less, there are writers who go on describing so-called new species u[)on the most imperfect material, from horizons from which numerous species of tlie same genus have been previou,sly described, without comparison with the types or with authentic collections of known species. The earlier authors, in the infancy of PahTontologj', before the great treasures of our crinoidal faunte had been brought to light, and without knowledge of the embryologj' of the Crinoids, may readily be excused for describing their species from such material as they had. But at the present day the only excuse for this class of work that can be found is the desire of the authors to see their names appended to the greatest possible number of species. A

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rLATVCniNID.K

Co3

crowning vice of tlio desn-iptionH niiiniifactuicd in thin way, nnd ono ncccs- muily Cullowiiig tlio nietlioils t'lniilovLMl, \n tjio frtHiuent nbHt-nco ol" any com- pnriHon with other foniiH. All wo have in nmny ciisen in the iiJ^MUiiince of the niithor that the mieeieM in wo unlike any other that ii compuriMin is nnnocossary. Wo have found in priwtico that a declaration of this kind is a badge of susijicion, and in one of the most common indieations of a synonym,

B URLING TONENSIS ORO UP.

Dorsal cup moderately deep, cup-shaped ; plates rather heavy, and with- out ornamentation ; arms long.

Flatyorinus burliDgtonensis o. nnd Sihm, Pla/e LXIX. Fiys. 3ct, b, c, d, c, /, <j, h, i

1S50. OwKN nnd SiirMMin; .Ifiiini. Arml. Nut. Sci. I'liila. (iinw series), \u\. II., Pail 1, nnd 1S52, I'. S.

(iecil. Iti'p. Ill' Wis,, ln«ii, nnd .Minn,, p. 5?iU, I'liilc 5.\, V\g. 5. 1S73. XIekk iukI Woutmkn ; (iid. Itep, lllinnis, Veil. V,, p, iU, IMiili' ;i, Firs, fi,^ h, e. 1S81. W. nnd Sf. j Uovisinn, I'lirt II,, p, "il (.Vend. Nut, Sei, I'hiln,, p. iH).

8\f», J', iiitji-naliia MiChks.nky; b;')'.l, Discriptiim (it New Species, p. 0. figured ill the Trans, Cliieni,'!) Ariid. Sei., Veil. I,, I'lnli' I, I''ii,'s. 'An, h, ns /'. Iiiii-Uinjluiifimn.

Syn. P. e.T!i,'rlH» II.M.i,, \V.^%; (leid. Hep. Inwn, V.d. I , I'nil II., p. 630.

Svn. P. iimhhi;u-hi,ilii>i ll,n,r„ 1S,-,S (not ISCl) ; iljid., p, WVi.

Syn. />. imcMfutmh IIai.i,, IS.-.S ; iliid., p. CIO,

Syn. /'. hiutus S. A. Mii.i.Kn, ISUlj (leol, Surv. Missouri, Hnll. I, p, 17, Fips, 3 nnd 1.

Of medium nizo or les.s. Calyx a little higher than wide in the adult, width and length about equal in young specimens, the ventral disk occupy, ing ono fourth of the height. Dorsal cup bowl-shnped, slightly spreading to the arm bases; the base rounded in largo specimens, more or le.ss flattened and proportionally shorter in smaller ones. Plates moderately thick and without oruiimentation ; tlio radial.s toward the facets somewhat thickened or longitudinally convex, so as to give to the cup, as seen from below, a slightly pentangular outline. Basi-radial and interbasal sutures a little grooved.

Basal cup saucer-shaped, its height equal to half the length of the radials; the interbasal sutures rarely visible in the adult; the colunm facet circular and but little impressed. Radials about as long as wide, in large specimens somewhat longer, in smaller ones a shade shorter ; wider at the top than at the bottom, the upper margins slightly incurving, and the superior angles truncated, especially at the anal side, where they form a

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wiilu ami iiiilu'i' il('i'|) iioU'li. I'licc'tM uocup^ing Imlf tho >vi(lili of llie liliili'.H, Hoiiii-circiiliii', uiil_\' I'Xfuvatt'il iit tlii'ir diiIit facfH, the imii'i' cilgi's ui tliu platu.i lii'iiig ill a dtiai^lit lint.', which in xlightly iiuti-hi'd fur tho lia.^M.igo of till' uiiibiilacral vomhcIh. Cusiul.s iiiuiloiali.'!}' largo, Huli'iit'iitagoiial; their lateral iiiaigiiis very r<luirt, direeted uutwani ami Mli^ihlly iipwanl. Ditt- liohiils ami [jalmarH oiiee and a half an wide as long, the former giving oil ail arm to one .tide, and two iialmurs to the other, the latter two ariiiN, making three arm.H to eaeli Mnli<li\i>ion, or hix aniiH to tin* ray. ArniN rather uleiider, vi'i'v slighilv tapering, rounded on the haek, their live or mIx pro.x- iiiial plates wedge-lonii and uiiiserial, the siieceediiig ones hiserial. 'J'ho ami plates are nearly as long as wide, and each one is marked ]>y a small, transverse elevation projeeting iVoni tho isides of the arms. I'iiiiiulos nearly, or i|nite. in contai't laterally.

A'entral disk depre-^sed lieinisi)herieal ; orals large, tuberculous, exccn. trie, and asynimelrieally arranged ; disk ambulacra short and composed of few rather large pieces. The inlerambuhu'rals consist of a single row of three plates, of which the two at the sides arc very narrow and bend abruptly outwaril ; the middle one large, mid resting invariably against the ornls. The niidille ])lalo of the anal side, which is larger and sub-f|uadiaiigii. lar, is followed by two medium sized plates, ami tlu'se by iiuinerouH piimller ones, which together form an elongate protuberance or short aiinl tube, 5 to (i mm. in length, directed upward, and curving slightly inward to tho middle of the disk ; its lower margin, bordering the posterior oral, slightly truncat- ing its outer edge. Column moderately twisted, the joints decidedly elliptic in tho adult, almost circular in young s])ecimcns.

ILiriviiii iKiil Lucitllli/. — Lower Ilurlington limestone, Burlington, Town; and found at tho same horizon throughout Mi.s.souri, and in Southwestern >i'ew Mexico.

Ji'iiiiiid". — Tho subglobosc form of tho calyx, but ptill more the con- struction of the ventral disk with its incurving anal tube and the largo interanibiilacral plates which invariably touch tho orals, distinguish this species from all others known to n.s.

In describing this species we had for comparison over sixty s])ecimcna of nil sizes, from T2 mm., including arms, to 8 cm., showing the modifications that took place in tho growing Crluoid, in the form of the calyx and the structure of the arms. Tho calyx of young specimens is shorter, the base more depressed, the arms zigzag, and composed of long wedge-form plates,

Pr.ATYCntNID.K.

till' piiiniiK'H proportioiiiilly liirge iiinl pliiccil wiilc apiiit. Hull di'xciila'il n ratlii'i' }oim^ KjK'cimi'ii, t'vidiiitly of tiiin Hpocii-x, iim /', niiv/iij'"niiis, imntlicr witli Homi'wliiit (Ifi'por Hiiliiii' iiru'M iih /'. i.i:tir/!i.s, ninl duo in wliicli llic miiiih iiro iiM yi't ill their t'liihiyoiiic hIiUc t\M /*. iKiiliilirni/iiittiiH; wliilu S. A. MilliT (k'xci'ii)ud iiH /'. liiiitKn n Hpuciiiiun ttiiuwing tliu niml tubu.

Flatjrorinus aymmetrioui w. nmi Sc.

J'luk III. I'I'j. Id ; J'liilc I.MX. ////■>•• /". *. »■

IMIi). \V. nudSi.. i (iiul. Itcp. Uliiiui-, V(/l. VIII , |i. ls(), l'l:ilc 1:,, Fiif. S.

Hi'low inciliiini ni/.e' ; tlio Hpcciiiu'iiM of V\^\\t cdldi', in miiikctl rnntrn.xt (o Dii/i'iiTiiiitu iniinidfiis iiiul otliir Hiiccios IVoiii llic muw Ideality, whieli me (lurk, ('iilyx ncnily ns wiilo nn lii>.'h, the veiitiiil dixk (leiuesscfl, nnil oceiipy- ing in ndiiU HpeoimciiM one tliini of the totiil liei^dit, a little iiidic in ilie youiij,'er ones. Doi'mhI cup Hulttiniiiimle, risinjr j;iniliiiilly fi'diii llie top of tlie bnmils to the arm liases; liasal cup small and short. I'latcs modeiately lionvy, almost Hat except for tlic general ciirvafure of tlic cnp; tlic Kur face without oninmentation ; the hasi-rndial niid interradiid sutiues di8- tinctly channeled, the inteihasal ones iiivisilile.

Basal cup shallow, rounded ; the coliirrni fiicet proportidiially large and circular. Radial.s a little longer than wide, increasing in width upwanls; the liinhs slightly ciu'ving inward, their upper faces nloping ; the middle por- tions of the plates somewhat projecting and thickened toward the facets ; the edges rather distinctly beveled. Facets shallow and directed upwards, their width equal to one half the diameter of the radials at the upp' r end Ccstals trigonal, Hinall, but completely filling tlie facets. Disticbals and pal- inar.'? one fourth wider than long, nnil the lower plates pinnule-bearing. The upper plate of the distichals gives off an arm to the outer side and two pal- mars with two arms to the inner side, making six arm.s to the ray. The two proximal nrm joints following the bifurcations cuneate and singly arranged, tlio succeeding ones biserial. Ventral disk low-convex, the plates very numerous and small. Orals rather s^-mmetrically arranged, the posterior one a little larger than the other.s. The covering ]datcs of the ambulacra form narrow ridges compo.«ed of two rows of small alternating pieces, which bifurcate upon the disk, nnd remain closed to the ends of the distichals. The interambulacral spaces are deeply depressed, and at the four regular sides of the disk consist in full grown .specimens of fifteen or more pieces, of which

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tlie middle one of tlio (ir.si low is Nuldriaiigidiir in Diitline, and a« largo as four or li\(t of llic odicr.s l();i(llici'. 'J'lie inidillc iiImIc of the anal i-idc is soniewlial, isnndler, and sid)i|uadr.uigidar. It is lulloucd \iy a very larg(! mini- 1)1 r of niiniile jiieees, \vlii('li I'drni a cireidar, well delineil, lounded iirotnlier- ance, ex(ending I'roni llie orals (o the lar;^e (jiiadran^iidar ))lnte. In }<'iin^' K))eciineiis ( I'lale 111., I''ig. Ill), llie oials are as large as in llie adidi ( I'lale liXIX.. l''ig. Ii) ; tliey are even more icgidarly arranged, and stand out ecjn- s](ieuoiislv over the sorroiinding |iart of the disk ; the aniimlaera are shorter, and the interanilmlaeial sjiaees consist of oid\ live or six jiieces, ol' which the niiilille one hears a central nodi', ('olinnn decidedly ellij)li(', e\ce])t the proximal joints which are eiri'ular, and it has a ra|)id twist. The length of the stem, as oiiseiveil in several sjiecimens, does not exceed Ifi cm.; its telini- iial pari, after giving oil a few short iateial cirri, ends in a shai'p point.

Jl'iiizdu iiiid Lmidilji. — Kinderhook group; Le (ir.uiil, .Marshall Co., Iowa.

Ti/iii>f in the collection of Wa<hsniiilli and Spiinger.

lidiKiil,^. — This species dilfers from /'. Jj/r^'-.x,?/ of the same hori/on. in llie more spreading cal\ \, heavier plalis. giooveil siilnie lines, and the sh<irl and idiinded hasal ciqi witli(jiil project ing rim.

Platycrinus pileiforinis II mi..

Phi. I. XIX. i-\.j. r,, »/„/ rial, I. XX. ri.jx. hh,, h.

l>i:,S. II. U.I ; (h.,1 |(,|, !„«:,, V.,1. I., I':,rl I I . p. f.J'.l, I'l;,!,- V. \.,.j.. |„, /,, ,-.

h^il. \\ iiiid Si- ; Iti'viniiiii, I'iiii II , |i. (" Ht'iwciril. Aiviil. Niil Sci. I'hil.-i, |i. ils).

^m. /'. ,;i,r/ir>iu,,i fS. A. .Mil.i.Kii ; (m'i\. Suiv. (if .Mi-viiin, liiill. t, p. a:), i';,,ii 1, l"!;.'-. d, 7.

Of medium size, llors.il cup deep, iihoiit as high iis wide, somewhat expanding upwards, louiided at the liase. I'lales lather thin, e.\cepl the radials Induw the facets; surface smooth.

IJasal Clip hasin-shaped, evenly rounded, its height fully half the length of the radials, the miildle portions slightly excavated for the column facei. whicli is circular; interliasal sutures rari'Iy visilde. Ifadials a little longer than wide, the sides almost paialld. the upper I'ai es dee)ily notched, the iioti'h of th(! anal side considerahly wider ami ninch deeper, giving to tin; ])osteiior radials an asymnu'triiid form. Facets senn-eircular, less than hull' the width of the plates, their upper margins hut slightly excavated, ('ostitis triangular in outline, generally occiipsing the- full widlli of the facets, those of the same ray in sutiiral contact laleially, fully lwii'(^ as wid<' as long, and giving off two arms eai h. Anns four to the ray. very hea\y, Huhcylindrieal,

I

IM.ATVCinNMD.K.

(;r,7

tapering only noiir tlio (ipw ; iIh; two lower artn plates i<iitiirally ('oiincclcd mid (luailranj^iilar; llie live or nix fiiccci'dinjr ones wciljfc-l'onii and iini- Hi.'rial, tlioHc hcyoml inli'rlo(,'kin<^, and jrradiially tin'iiinj,' into two .scries of traiiHVifrr'L' jjieccn with jiarallel upper ami lower faces. I'innnlc.s JM'avy, knil'u-liko, lliL' jointM long and tliickciicd at llie ends. \'enlral disk liiilf the Iieiglil, ol" IIk! dorsal cup, fialtoiiLMl at tiio miinniit, \\iv sides sleep, almost, in n vertical line; with liie radiaJM. The interainhidacral spaces at the lour regu- lar sides generally Consist of nix pieces, arrangi'd in two rows; the middle one of the lower I'ow large, the two at the sides very lidlc cm \'ing, the three upper ones Small. The inleranihuhu'rals of th(; anal siile consideriilily wider, the middle plali' of tli(j first row shorter and desceuiling to a lower level than the coii'espondiug plates of th(! other sides, its lower facen making a riiiht angle; the plates ahov.; numerous, forming a small protuheranco, which opeiLs out la1(-'rally, ami is separateil I'rom the' cjrals hy several moderately large plates,

//(//■('.;■(/// (//((/ l,ii<<iHli/. — fiower Hurlington limestone, 15iuliiigl(in, Iowa, and llannihal and Scdalia, Mo.

7///"' in the (WorthenJ Illinois Stale collection, Spriiigliidd.

Jiiiiiar/i'n. — This cpecieH ntsemhles /'. /)iir/iii;//ii>ii iisis, hut differs in the more elongate form of the calyx ; it has no /such anal tuhe as tli.at species, its amis consisting of a simple o])ening directly thiough the disk.

Miller's y. rdrc/iiHiniii, as de.scrihed from the basals and ladials only, can- not he separated from I'. iidiifdVnilx.

Platycrinus corbuliformis Kowm v an.i Hahi:. Plate LXXl. /•'/>. Ila,h.

l>^'./| K.'iiisi.s City Srii.jili.,!, ji. I i;i, I'l.'ili' :(, KiV's. 1 .■iimI 2.

01." the ty|ie of /'. biii'/iiii/loiicnuin, hut tlie plati's heavier and more spread- ing. I)cscrihc<l from ispi-cimens in which oidy the hasals. railials :ind a few of the inlerradial plates are presci'\cd. Dorsal cuj) hasin-shaped. rallier rapidly s|)readiiig. and distinctly (luiiapadohatc' at the np|}er end -. the plates convex and jn'rlectiy smooth; inlerbasal, hasi-radial and interradi.il suture lines rather deeply depressed.

lliiHalM forming a shallow cup, with a dcej) circular de|tression at thii lower face for the reception of tla; column, whic'i <j"(nipies ahout one third the diameter of the cup; the lower margins a lililc liulging, and cinviiig

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TIIK CKINOIDKA CAMKRATA OF NOUTII AMKRICA.

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gently iipwiinl to iiiet't the riuliolH. Kiidiiil.s as wide as long, one fourth wilier near the toj) tlmii at the holtoin ; facets very large, oceii])ying more than a third the width of the j)late.s, and reaching down to alniowt one half their length ; tiiey are directed ohliijiiely upwards, suhcircular, and but slightly notched at the upper end ; the surface concave, and perfectly smooth. The limhs of the radiuls bend a little inward, their upper faces abruptly truncated ; they sujiport three rather small interradial i)lates, of which the outer ones face the costal.s, and are in part interundiulacral.

Ilorizon unci Locdili/. — Da.se of the Lower IJurlington limestone; Bui • llngton, Iowa.

'I'l/pis in the collection of Mr. R. R. Rowley of Louisiana, Mo.

PlatycrinuB aequitemua s. A. Millkr. riatc LXXI. Fly. 12.

1S91, S. A. MlM.KIi; liiill, 4, (icol. Surv. Missouri, p. W, I'latc 1, Fif;, 13.

Svn. Vluliji-niuti ciirryriUrniis KdWi.Ky and IIakk, IS'Jl ; K.-iiiMis City Sciciilisl, ]i. 98, Pliclc 2, I'iR. 5,

A moderately smnll .species of the type of P. jnlcifonni/i Hall ; described from the basals and radials only. Dorsal cup to the top of the radials obcon- ical, as wide as high, truncated below, the sides very little convex; cross- section somewhat quin(|uel()bate. Plates flat and without ornamentation ; suture lines not grooved and rather ob.scure.

Basals closely anchylosed, forming a truncated, rapidly expanding basin, equal in height to half the length of the radials; the lower face sufficiently depressed to contiiin (he proximal stem joint, which is circular and slightly serrated around the edge. Radials longer than wide, gradually expanding, convex longitudinally, the convexity increasing toward the facets; the sloji- ing u])per faces toward the ontd side deeper, and forming a broader notch ; tlie fiicets of the two posterior radials puslied to one side. Facets semi- ovoid, slightly concave, the upper edge a little excavated ; they occupy half the width of the plates, and nearly one third their length, jiroject abruptly outward, and face laterally.

ILirhon and LomUfi/. — Chouteau limestone; Sedalia, Mo.

T//2>e in the collection of Mr. F. A. Sampson, Sedalia.

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Flatycrinus insolens Kowi.kv and iiauk. riate LXXI. Fi,j. lo.

1801. Kinisiifi City SciiMilisI, p. 'JS, I'liiti: 2, Vij;. 4.

Type of P. hnrJiii(jl(ini'um ; dusciilji'd from the basals and radiul.s. These plates form a moderately small, spreadini; cup, with very sliyhtly c(jiivcx, neai'ly straight HJdus, and hiowlly truncated base ; cro.-s-,section near the upper end obscurely pentangular. Plates rather strong.

Base saucer-shaped ; ujjper face produced into sharp angles; lower face perfectly flat, spreading outward into a short, well defined rim, fully twice as wide as the column, and somewhat fluted at the margin; column facet round. Interbasal sutures invisible ; basi-radial and interradial sutures slightly depressed. I{a<lials about one fifth wi<ler at the top than at the bottom, their length equal to their greatest widtii ; longitudinally convex, a little contracted at the upper end ; the faces supporting the interradial pieces almost horizontid, and but slightly truncated at the anal side. Articular facets occupying one third the width of thi; plates; directed obliquely upward, their surfaces being covered with fine radiating striaj and an obscure trans- verse ridge, but without perforation.

Iloriion and Lornlih/. — Cliouteaii limestone; near Curryville, Mo.

7}/pes in the collection of Mr. Rowley.

Jlcmarks. — This species resembles/'. ai/in'/enviH Miller; but tlie latter has a more concave base, the facets of the radials are more jnojecting and directeil almost horizontally. It also approaches /'. JJiiU.sl, but the radial facets are nuich wider and larger generally.

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PlatycrinuB Britsi « A. Arir,i,i;n. Plate LXXI. FUj. JO.

1991. S. A. Mii.i,En ; Hull. Nn. 4, Gi-ol. Siirv. Missouri, p. 23, PInIo 3, Fi^^s. 3 niul 4.

Comparable with P. (cquilcrnns Miller, and P. Imolcm Rowley and Hare. Of medium size. Caly.x to the top of the radials cup-.shaped, wider than high, bro.'ully truncated at the bottom, the sides convex, more rapidly expanding at the basals than at the radials. I'lates thick.

660

THE CKINOIDKA CAJIERATA OK NORTH AMERICA.

their surface smooth ; basi-mdial and intermdinl suture lines distinct, but not grooved.

Biisals forming a low basin, with a short rim extending outward from the lower end ; the bottom slightly excavated for the reception of the stem ; the plates closely anchylosed, and interbasal sutures invisible. Column facet large, circular, the extreme outer margin striated ; axial canal very ,«mall. Radials as wide as long, a fifth wider near the top than at the bottom, thickened around the facets; the sides supporting the interradials very short. Facets unusually wide, occupying three fourths the width of the platO'', directed obliquely upwards, a little concave, and provided with a low transverse ridge. The costals occupy the whole width of the facet, are extremely short, and very slightly angular ; their sloping faces with a trans- verse ridge and a shallow fossa to the outer side of it. Structure of all other parts unknown.

Horizon and Locality. — Chouteau group, at Pin Hook bridge, Mo.

Ti/jK in the collection of Mr. Sampson.

4ii

Flatycrinus pisum Rowley and Hare. Plate LXXI. Figs. 13a, h.

1S91. Kansas Citv Scientist, p. 113, Plate 3, Fig. 3.

A very small species. Calyx spherical, about as wide as high, the dorsal cup a little higher than the tegmen, the sides almost at right angles to the truncated base. Plates finely granular, the sutures moderately grooved, except those between the basals, which are invisible.

Base disk-like, flat, only the edges curving upwards; the place of attach- ment for the column circular, elevated slightly above the plane of the base ; its extreme outer margin striated. Radials a little wider than long, the sides parallel ; facets occupying half the width of the plates, and nearly a third of their length, semicircular, having no notch at the upper edge. Interradial plates somewhat depressed and directed obliquely upwards, ex- cept at the anal side, where they are erect and form the base of a rather prominent anal protuberance, composed of minute plates. The orals are large and convex ; they rest upon the first row of interradials and against a large radial dome plate, there being no covering plates in the calyx. Structure of arms unknown.

1!

i

PLATYCRIMD.E

UGl

Ilorhon and L ^alit//. — Bnso of Lower Burlington limestone ; Louisi- ana, Mo.

Ti/pe in tlio collection of Mr. Rowley.

Jiaiuirks. — Fron» the small size of tiie .specimen, and the structure of the ventral disk, we are inclined to believe that it represents a very young form of P. biirluii/Zuiwiisis.

Platycrinus quinquenodus White. Plate LXXI. Figs. Ua, b, c.

1S02. Wlllir. ; Proceed. Boston Society Niit. Hist., p. IS.

1S81. W. and Sr. i Revision, Part II., p. 71 (Proceed. Acad. Nat. Sci. Pliila., p. 2l«).

Syn. P pliinoiasali) Howlkv and II.\nK, 1891; Kansas City Scientist, p. 97. Plate 2, Fig. 1.

Of moderate size. Calyx rather rapidly and evenly spreading from the truncated base to half the height of the ventral di.sk ; the lower brachials directed almost horizontally. Ventral disk as high as the cup, distinctly convex, extended outward to the top of the distichals, and forming well de- fined lobes, which give to the calyx a sharply quinquclobate outline. Plates of the dorsal cup heavy and without ornamentation, except that the base is marked by five rounded nodes, interradially disposed and directed down- ward. Basi-radial and interradial sutures channeled.

Basal cup deep, fully two thirds the length pf the radials, truncated at the bottom, the sides gradually spreading. Eadials as long as wide, wider above than below, the median portions below the facets much the thickest ; the lower faces almost straight, the upper angles deeply truncated and forming with the corresponding sides of adjoining plates deep notches; the notch of the anal side considerably deeper, extending down to fidly one third the length of the plates. Facets semicircular, facing almost horizon- tally, the upper end not notched, or only a very little. Costals pentangidar, the upper faces concave. Distichals nearly twice as wide as long, those of the same ray in sutural contact laterally, the upper ones axillary. Structure of arms unknown. Plates of the disk nodose, except the interambulacrals of the anal side, which are barely convex. Orals very large, almost symmetri- cally arranged ; the posterior one a little larger and wedged in between the others. The plates of the disk ambulacra large and tuberculous, extending out to the ends of the distichals and forming rigid tubular extensions. Inter- ambulacrals three, the middle one twice as long as the two at the sides, but without touching the orals. The middle plate of the anal side considerably

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rilK CUINOIDKA CAMKHATA OK Nt)l{TII AMKlUt'A.

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smaller tliaii tlie corresponding plates of the other sides, and placed at a higiier level than the middle one. The plates surrounding the anal opening not projecting; the opening low down, and directed laterally,

IJur'aun (w<l Locul'di/. — Upper Burlington limestone; Burlington. Iowa.

Tijpi; in the Museum of Comparative Zoology.

lUnmrkx. — This species dilTors from all others of this group in the abrupt spreading of the lower brachials, and the quinquclobato outline of the calyx. The nodes upon the basals, although quite distinct in the type, are in other specimens but faintly represented, and sometimes absent altogether.

Platycrinus Halli Siu.m. Plate LXXII. Fiijs. da, h, ami T<i, h.

HI15, SiirM\nn; Ciiliil. I'lilivoz. y,iss. Xorlli AiniT., p, 3S? (Tniis. Ar:iil. Sci., St. Lduis, Vol. TI.)- 1S73. .\ltKK ami WcjiiTiiKx; (iccil. lii'p. llliiiciis, Vul. V., p. 4JI-, I'lali' 3, Kijis. 3ii, h, c, il.

Svu. /'./,/„,;«,« Ham, (iiul (). iiml Sin M.) ; Grol. li.p. luwii, Wil. 1„ V-m-\ II., I'biio S, File's, tw, b.

Svn. V. i.liii Hai.i,, ISOl {mil Dk Koxinck mul I.Kiiox ISjH); Doscr. Nc»v Spec Ciiii., p, 10.

A rather largo species ; the calyx large in proportion to the length of the arms, one fifth higher than wide; height of the ventral di.-k, as compared with that of the don^al cup, as two to three, the former hemisi>herical, the latter bell-.shaped. widest around the (iicefs. Plates of the dorsal cup slightly conve.v, thickened below the facets, and rather heavy throughout ; inter- radial sutures somewhat depressed, giving to the cup a slightly pentangular outline.

Height of base equal to half the length of the radials, the outer surface regularly rounded, except beneath the colunm, Avhich rests within a circular depression ; sutures l)efween the plates oiten visible. Eadials a little longer than wide, .slightly spreading, somewhat irregular in form, espcciidly the ])osterior ones, which arc frequently wider than the others and asymmetri- cal, owing to the wider and deeper truncation of the n]iper angles at the anal side. Facets rather wide and deep, .semicircular to semiovoid, the npper edges slightly notched. Costals irregularly pentagonal with concave upper faces ; rarel}' trigonal. Distichals, palmars and post-palmars from once and a half to twice as wide as long ; the distichals of the same ray in sutural contact laterally, but among the palmars and post-palmars onl}' the plates of the same subdivisions. Arms seven to eight to the ray, quite short and moderately heavy, their two or three proximal plates cuneate and alternatel}' arranged, the succeeding ones arranged biserially ; the latter rather long,

1

rLATYCRIN'invE.

CCS

4

llieir upper nnd lower faces pnrnllel, the outer lateral faces provided with a sharp projection placed in front of the pinnules.

Ventral disk convi'x, j^riidunlly curvinj^ to the siimiiiit, quin(|Uclobatc as seen from uliove, the plates slightly convex. Orals rather a.'^yintnetrically arranged ; the posterior one larger than the other four, and pushed in be- tween them. Anibulacrol plates of the first order consisting of but few large pieces of rather irregular arrangement, those of the second order about one half smaller. Intenimbulacral jilates of the regular sides five in two rows; the middle one of the first row huge, elongate, hexangular, much narrower at the top than at the bottom, and deeply wedged in between the radials ; the two at the sides very narrow, the edges toward the ambu- lacra deeply .scalloped by adjoining covering-pieces. Anal side considerably larger, the notch between the radials deeper ; the middle plate much shorter, wider and pentangular, supporting upon its sloping upper faces two smidler pieces, which, being at a higher level, form with their lower faces and with the sloping lower sides of the middle plate a sharp angle; the plates of the first row arc followed by nmnerous smaller ones, which form a largo rounded protuberance, containing the anus. Column moderately large ; the three upper joints circular, the lower ones distinctly elliptic.

Horizon (did Lcrd/i///. — Upper Burlington limestone; Burlington, Iowa.

licitHir/fs. — This sjiecies resembles P. plhlforinix in the form of the calyx ; but the plates are heavier, the arms comparatively shorter, not so heavy, and much more numerous.

Platycrinus acclivus s. A. jriLi.F.u.

1S91. S. A. Mii.i.i:k ; (i.nl. Suiv, Missouri, Bull. 1, p. U, I'lulc 1, Figs. 9 nnd 10.

According to Jliller, the dorsal cup somewhat obconoidal, nearly one half higher tiian wide, .slightly " angular in the direction of the arms," sutures distinct but not beveled, surface apparently smooth, but the specimen may not have preserved the surface ornamentation. Basals form an obconic, sub- pentagonal cup, a little wider than high, and truncated below. Eadials a little longer than wide, very slightly expanding above, and terminating in an upward, central prolongation for the reception of the oostals. Facets facing upward ; less than one third the width of the plates, subcircular in outline, with the exception of a slight truncation at the inner side, and a small concave ambulacral furrow. Column round at the proximal end, " the

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THK CHIXOIDKA C'AMKRATA OK XOlMIt AMI'.HKA.

plates riuliutfly furrowed nenr tlie outer iiiiirgin." Miller i^iiys : '• This species need not Ijc mistaken for nuy other, beeause in /'. fi/diiim, uud others huvin^f any resemblance to it, the angularity of the eup follows the radial sutures, and there are deep exeaviitions lor the insertion of the second rudials (costals)."

Ilnri-nn ami LordHtij. — Upper Burlington limestone ; Sedalio, Mo.

Tiijic in the collection of S. A. Miller, Cincinnati.

JltiiKirlis. — We do not ((uite understand what Miller means by " radial sutures;" whether he alludes to the liitcrhmal sutures which are radially dis- posed, or to the /wto'-radial sutures. The species was described by Miller from an imperfect specimen in which, as shown by the figure, only the basals and jjortions of the radials were preserved, and it is possibly identical with some other Hiulington species. Our description is made after Miller, we having no specimens for comparison.

Flatycrinus inoomptus White,

Plate LXXI. Fitjs. 1, 2, J; P/atc LXVII. Fhj. G.

lSfi2. WiilTK ; liiist.in JiHini. Nat. Hist., V,il, VII., p. ,",0;!.

\<n. -MtKK .■liul WollTllEN J Grcil. Hep. Illiiinis, Viil. v., ).. ■t,")9, I'llltC 3, Fig. 7.

18S1. W. mill Sr.; Hcvisii.n, I'lirt II., ji. ri (Prnrooil. Acail. Xiit. Soi. riiili. , p. 2in).

Almost as large as P. Ilulll, and in the form of the calyx often closely resembling it, but differing essentially in the branching of the arms. Height of dorsal cup compared with the width as four to five in large specimens, and as three to four in small ones, the base of tlie latter being proportion- ally shorter, and rather distinctly flattened ; the sides .somewhat convex. Plates moderately heavy, the .surface smooth or indistinctly granular, their edges slightly beveled, and the basi-radial and interradial suture lines depressed or broadl}' channeled.

Ba-nls more or less truncated at the bottom ; the intervening siitures frequently visible in young specimens. Radials about as long as wide, the height rarely exceeding the width, a little wider near the top than at the bottom ; the median portions of the plates much heavier than their mar- gins; the upper faces on either side of the facets sloping and forming a notch, of which the one at the anal side is wider and deeper than the others. Facets semi-circular to semi-ovoid, facing obliqucl}' upwards, very little ex- cavated, their upper edges straight ; the ambulacral notch, if represented at all, very small. Costals pentagonal or trigonal in the same specimen. When

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C66

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trigoiml, the outer end of tlic first distichiil barely toucliCM tlic radials. Dis. ticlmlw pliu'cil o!)li(iiiely, iiboiit us long as lialf tlieir wicltli, tlio axillary obtusely angular above. There are IVoni six to nine higher orders of br " iuls above the costals, of whieh the proximal ones consist of two piccv-s oaeh, the succeeding ones of three each, all giving ofT from their axillaries at one side an arm, and from the opposite side the next order of brachials. The plates of the diirerent orders decrease in width upward, but not in length, those of the higher orders being almost as long as wide, vhilc those of the lower orders in largo specimens arc almost twice as wide as long. In young s|)ecimens idl the bi'iichials are proportionally longer, and the bifurcations extend to nearly the full length of the rays; while in the adult they rise to only half way tip. Arms biserial from the secoiul plate after the axillary, short for the size of the cnlyx, and all rise to the same lieight. They arc comiiosed of moderately long joints, ami each one has a well defined lateral projection for the support of a pinnule.

Form of the ventral disk unknown ; we observed, however, from a crushed specimen that it is composed of convex pieces apparently of a simi- lar arrangement to that of P. IInlll, except that the ambidacral pieces are more projecting ond comparatively smaller. The large interanibidacral plate of the first row at the anal side is somewhat bulging outward, and wider than long. Column elliptic and twisted, the long diameter of the joints being at 25 cm. from the calyx twice as long as the short one. The joints increase gradually downward to three times the length of those at the top, and near the base of the stem give off from their sharp ends two rows of small cirri, whicn follow the twist.

Horizon and LocalUy. — Upper Burlington limestone ; Burlington, Iowa.

Ttipc in the Museum of Cotniiarative Zoiilogy.

linnarJifi. — In the branching of the arms this species approaches the genus Endaihcrlmis, but while in the latter the .successive orders of brachials form tubular appendages of the calyx closed from all sides, in P. incomplm they retain the characteristics of arm plates, being provided with open furrows. The type specimen shows the bifurcations only to the third axil- laries above the costals, and it was supposed the species had but foiu- arms to each side of the ra}- ; while in fact it has from seven to ten, or as many as twenty arms to the full ray in some specimens.

84

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I

ceo THE CKINOIUKA CAMKHATA OF NOKTU A.MKUICA.

FlatyOrinUB lodensls IlAi.r. ami Wnnr. Plate LXXI. Fii). G.

1S75, II\M, ami WlllTPlHI); (li'iil. l(c|i. Ohio, Vnl, II , |>nrl II., p. IflS, riiilo 11, Fi)?. 3. 1S81. W. mill Siv; UcvUioii, I'iiil II,, |i. ',i (I'mcccd, Acail. Niil. Sci, I'liilii., p. iil«).

Of iiR'iiiimi ^^izl'. Dorsal cup deoply eup-nliiipi'd, (lie wides iiliiiont pnr- allfl ! tlic plutes tliiii und without ornaint'iitution ; the sutiiru linos not groovi'd.

lla.siil.s placed alniost hoii/ontally, forming a very sliallow, Hauccr-sliapcd Ijcntangiilar di.sji, witii a wliglitly jirojccting column I'awt. Kadials ratlicr large, their lieight equal to the wiilth or slightly exceeding it; their sides almost parallel, thickened toward the facets, the upper liices ii little sloping at the end.s and forming a small notch. Radial facets deeply excavated to fully two thirds the width of the plates. Costals trigonal, the lower face distinctly convex. Distichals two ; the first resting completely within the facet, once and a half as wide as long; the second a little wider, and free at the outer side, but suturally connected nith its fellow of the same ray; the upper angle obtuse, supporting two .'iruis, making four to the ray. Arms proportionally long and heavy throi gii')ut their full length, rounded on the back and sides. They are composed from the second or third plate up of a double series of short, transverse pieces. Structure of ventral disk unknown. Cohunnar joints very slightly elliptic.

Horizon and Lorii!!/i/. — Cuyahoga shales, Waverly group, at Lodi, Medina Co., and at Royalton, Ohio.

2'i//ic at Columbia College, New York.

]iiiit(ii7rn. — The 'o.'v and size of the disticlmls are not correctly repre- sented in Hall and Whitfield's figure, and were changed in our figure from a specimen in our collection.

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Platy.^i'inuB cor ,tus Umi. .nd Wiiirr. PMc XXL Fig. 8.

1803. II.M.i, niiJ WiirrriFin; (7(^1 Ij^p, \. y. Smt.: Ci.li Nul. Ilisi , p. 51; mid is;,'), (ic :. Smv. i.f Ohio, V.il, 1„ ISii II,, [. \m, I'luh- 11, Kic 1.

Tliif* Hpcc'ioH wo only know from flio (k'scription ami fijriiiv. Dorniil oiii) broad, nhort, concave at tlic bant' for tbo reception of a larj,'L' colinnn. I'latos without ornamentation. Huso one third tlic length of the (b.i'sal ciii). fonii- iny IV sharp angle at tiie lower edge, ami Mlightly projecting outward. Kadialx wider than high, noniewhat .spreading. Costal.s nubpentangular. with (tliort lateral faces. Tiie tlistichal.s longer than the costal.s. Arms four to five to the ray, short, strong, and biserial.* All other parts unknown.

Ifirivnn (i/iil Lordliti/. — Shales of the Waverly group at UiehfieUl, Sunnnit Co., Oiiio.

Tijjm in the New York State Cabinet at Albany.

FlatycrinuB ollioula s. a. JiiLT.i;n.t

1391. 8. A. MlLLKUi (inil. Hep. Missouri, Hull. \, p. 19, I'liite 2, Firs, 7. 8.

From medium si/.c to larger. Dorsal cup tub-shaped, having a wide, flat bottom, .slightly constricted at the top of the basals, whence it expands very gradually upward.s. Plates thick and convex ; sutures beveled ; surface finely granular. Basals stretched out horizontally, forming a disk of which the edges project beyond the lower ends of the radials in the form of a rim, the latter being the only part of the base seen in a side view. Kadials a little longer than wide, slightly spreading, their greatest convexity below the facets, the lower face forming a straight line, the up|)er faces not notched nt all, or very little. Facets shallow but wide, occupying more than two thirds the width of the plates, and facing upwards. All other parts unknown.

Horizon and Loculiti/. — Chouteau group, at Pin Hook bridge, and at Loucke's quarry, near Sadalia, Mo.

Type in the collection of Mr. Sampson.

• Tlio (Icicriptinu siivs fcuiv nrms in llic thrre nulcrior rays, nnd five in the two posterior ones ; liut if tlio position of llu' snmll Imsiil is com'clly llgnrisl, Ihc livi' arms do not occur in llic posterior, but in the anterior mys.

t We are unable to give a figure of this species, and the description is uuulo uflcr Miller's.

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DOS TIIK CIUNOIDK.V CAMKHAIA Ol" NDHTII AMKIIICA.

j'LAXLs anoip.

Ciilyx olonf^iito ; tlio pliitoi tliiii ami without oriinincntntion ; upper faces uf the riuliiilH titruiglil. or M'ly little xlupiiig tuwiird the uiigieH.

PlatyoriDua planus <> and sn.

J'lotr /.XIX. Flijx. Ju, h, r, ,1.

W){). t)«-KN mill SiiiMMiii; .Tiiiiiii. Aniil, Nii(. !Sri. I'liilii. (iii'W nciici), Vnl. II., Tiirt^ T. niiil II., p. 'il \ iiUii L'. .S. Uo'il, 8iir\. Minn, l.nni, iiml Wisiv, |i. rjST, I'liili' fj./, I'ik. \,i (mil M, /•. I'fiillfni),

ISsI. \V. mill Si'.; lliviMnii, I'mt II, |i H (I'mirnl, Aoiiil. \:it. Sci. Vliilii., p. il'*). (iint /'. /)/,(»»» ll>i.t,, (li'iil. Ili'|i, Innii, Vul. I.. I';iii II., I'liiln S, |''i«.. (),/,// /'. Il.illi : imr f. /,liiiiii.u Mkk.k mill WolirilKs, (ii'iil. lii'p, llliliuis Viil. 111., I'l;ili' 111. I'iK. (1 /'. l'r,iH.;ii). Svii, I'Ifif'/i'i-iiiiK lilaomJirlilfMih S, .V. .Millkk, IsT'Ji Juuni. Ciuc'iii. Soo. Niil. Hist., Vnl, II., I'liilO I. -I, t'lK *•

A inoilomtely largo Hpocies. Ciilyx elongiito. Dorsal cup goblot-nlmpc(l, liijiiiiT liiiin wiilo ill liir;,'o Hpeoiiiii'U.M, hoiglit and width about equal in HinidiiT DiK'H ; l)a.-<id o'.i[) deep, obconical, slightly truncate nt the holtoin; radial.i a very little spreading to the facets, the latter projecting so as to give to the cnp, as sec;! from aliove, a slightly pentagonal outline. I'iates thin and pei'leeily smooth ; the sntiu'e lines rather indistinct.

Masai cup large, obconical, its hciglit ('(pial to two lil'ths the height of the dorsal cup; the lowi'r face slightly truncated but not excavated, obscurtdy elli|p|ic. and covered completely by the cidinnn. Kadials longer than wide, the sides almost |)arallel ; the lind)s somewhat intlected and knifedike at their superior edges, where they form almost a straight line with those of adjoining plates ; the median portions of the plates slightly thickened, thin- ning out graduidly toward the sutures. Width of the facets one third the diameter of the plates; horse-shoe-shaped, deeply excavated, and facing up- wards. Costals short, trigonal, occupying the whole width of the facets, their slo[)ing upper faces concave. Disticlmls twice a.s wide a.s long, aiul as long as the costals; the lower ones of the same rny in sntural contact. Palmars and post-palnuirs three fourths as long as wide, their lower plateo coiniected by suture. Arms four to each subdivision ; or eight to the ray ; very long, rounded on the back, and but very slightly decreasing in width. The arm joints nioderatidy short, the intervening suture lines distinctly waving. Pinnules long and in close contact laterally. The ventral disk, so far as ob.sorved from the frogments preserved, extends up almost vertically

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PLATYCKINID.K.

GtiU

▼

to nonr tho top of the flrnt row of intmrmliul pieceiN, which cuivo abruptly inwuril, BO iw to form with tho otlior plutoH ii Hat Hurrnco at tho top. Tiio NUiiimit plutoN flightly convex. Aiiuh I'.xoeiitric.

I/orhon iiml /.oca/i/i/. — l.itww lliirliiij,'t(iii limcstoiio; Hiirliiij{toii, lown, ami at tho saiiu- horizdii in Ilaniiihiii and Sfihiliu, Mo.

licmnrks. — This MpoeicH may hv readily ruongni/eil by IIm oxtronioly thin phitex, conical base, narrow and deei> hor.Mu->>lioo-Nhapod liicetM, hwg, xlendcr arms, eight to flic ray, and tho waviiij^ sutnro lincM lutwccn the arm plates.

We rej,'ard /'. ih/mis. described by Ifnil in the iJoslon "Journal ol' Natural History," a.i a young J'htlj/irlHiis f/lmiiis ; the type Ims unisorial arms, and a round stem, which dearly shows that it is an immature specimen. The ligin-o which Kali gives of it in Hull, t of tho N. Y. Slate Cabinet is crushed and somewhat misleading with regard to the form of tho dorsal cup. which is not tnrbinatu as described, but tlio siden are almost parallel along tho raflials, nnd upread u|iwards but littlo, if any. We (igure on Plate LXIX, Fig. 2</, a similar specimen, but somewhat more mature, which already has inter- locking plates in the upper half of the arms, while in the lower part the arms aro zigzag, and their joints long and uniserial. The joints of the young stem nro remarkably long and circular, resembling those of a young Comatula in tho Pentacrinus stage, being at .'Jem. from tho calyx almost as long as wide, and there are no internodal joints interposed between them. Another speci- men in oiu- collection, whi(di in all other respects agrees with the preceding one, has unisorial arms throughout like IlaH'H /'. ifiymts.

PlatycrinUB AgaSSizi W. and Sr. (nov. spop.).

P/iitc LXJX. Fiij. 4.

Syii. /', /)/,/,;«,, (?) VI. mill Sp. (not Oukn iui.I Sirt m ); fifol. Kcp. Illinois, Vol. VIU , 11. 198 VhW 10,

Vig. S.

Smaller than P. j>f)iiiiis. Dorsal cup elongate, the sides along the nulials almost cylindrical, very slightly expanding at tho middle, its lower margin produced into a sharply edged projecting rim, which in foi'm resendjies an upper Ktcm joint, but is larger and tripartite. Plates v..,y thin, without ornamentation, and the suture lines without groove ,.

IJa.sals forming a shallow basin, in height from ono fourth to one third the length of the dorsal cup. Hadials quadrangular, a little longer than wide; the plates .somewhat thickened longitudinally, giving to the facets some pronii-

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1

070

rilK CUINOIDK.V CAMKUATA Ol' NoKlII AMl'.HIC'A.

lU'iice ; tlii'ir uppi'i' iini^flcH iiol trunciilcMl, (jr vfiy ulij^flitly, and tlic Miipdior I'act'M of iicljoiiiinj^ linihs loririini^ iil/no.st ii n(iiiiglil lino. Uiuliiil I'liculs lallicr f^liiillow, facing npwai'cls. (JomIuLs wliort, ocenpying tliu full width of tliL' Hii'ctM, nid)trij(onal, tlni tij.'ijor anglo obfnsi?. niHli(dial.s and palnuir.s <is lonu' us tlu! cost als, and fully on(!e and a half iw wide as lonj;; (lie lower plates of llie same ray sutnnilly connected. Arms si,\ to the ray, e.xception- ally two or four in one of llu! suhdivisions; (liey are lonj^, cylindrical, and hut slii^htly taix'rinif. Arm plates placed ol)Ii(|Ucly, slopinj;- to the sides, the lines of union somewhat wavin;,^ Pinindes closely packed. The siructuru of tlie ventral disk has not heen observed, heing almost completely covered hy the arms in our specimi.'ns; (,idy portions of the middle plate of the (irst interradial row are visible, which at tin* four regular sides are nuirked hy a conspicuous, sharply triangular conv(!\ity, while at the anal side the con- vexity is (luailrangular, and the plate it>ielf bulges outwanl, indicating the presence of some sort (jf j)rotrusion in counectiou with the anus. Stem distinctly elliptic, the two upper joints circulai', ami smaller than the dia- meter (jf the basal rim.

Iforiznii and Ldfiilili/. — Kinilerhook group; Le (Jrand, Marshall Co., Iowa.

TiJinx in the collection of U'achsmuth and Springer.

Uiiiini-ks. — Tliis form was referr(Ml by iis in IS'.IO with considerable loulit to I*, jiliiinis (). and Sh. More perfect specimens since obtained show that it (iillers from that species more distinctly than we had supposed, and in reilescribing it as a new species we name it in memory of Professor Louis Agassi/.. /'. ji/>niiis is a larger speei(!s than /'. Af/(is>il::t, the base is conical in plac<! of roimded, and it has no such rim at the lower end. This rim, which is represent(.'d in every specimen, is so conspicuous, and rescmldes so closely a stem joint, that we wi're at (irst inciineil to reg.'ird it as su<'h, but on grind- ing its Hinfaci! wo discovered plainly the interbasal suture lines. P. iihiims also has a greater lunnber of arms, the arm joints are longer and about horizontal, while ill 7*. A'/(issi::i they slope at ipiite an angle outward. It (Iillers from J'. J'riillnii in the much snndler si/e of the caly.x, and in having proi)ortionally much longer arms.

i 'I

>»v-»S;UK«ti;ft*flLn'-"^tPsji.jn-j..-*-"^.

^.^^-^.JffiESlsSti^ £f ^ ^•'> if ^ tlt^A^

ri-ATVC IIIMD.K.

07 1

^

Platyorinus Prattonl Wiktmk.v. riati: AAA', /'/(/v. //, /,',

iHdO. Wdhtiikn; TruMS. Kvm\. Sci. HI. I.oui.i, Vol. I., p. .")(;'.l.

IbSl. W. inid Si'. ; Kcvi.siu]!, I'liil II., |i. 7KI'i-„ ,1, Aciul. .\ii(. Sri. I'liilii , |.. -US),

K\ii l: /,/,i,iiii {ill |i:irl)— (»«'i;.s Mini HimimahI); M.S. (i.^ul. lic|i. ol .Mini,. Iiiwii ini.l Wim'., |i. ;ii7, riair ,'■),/, Ki;,'. I// (licit |.„). AUii Mkkk iiinl \V()iirMi..N, |>ii;ii; c,,,] ll,.,,. Hlii,,,;^ Vnl III., |i. 1117, I'liilf Hi, Ki^m;.

A largo H|)f('ic.M of tlu! (y|H; of I'. phnms. (J.ilyx cloiipilc, very I.iiirc in propoitiuii to tli(! Iciij^lli of llii; iiriii.s. Dor.siil (Mip once iiml a half a« lii;i,li as wiilo, almost, cylimlrical alon^- iIk; radials, hnt nijiidly s|.rcailin;< at tliu l.u.sals, wliicli lorni u nio(K;ratily (lt'ci> pcnlanifiilar lia.-in with its nppiT anji;!es slij^htly curving npwanls; the lower niiiiMins projecting onlwanl ami roiin- iiig a conspicuous rim around the edge, which ol'len is twice; as wide as the colmnn. I'lates (piito thin and perlcctly sniootii ; the radials sligiitly tiiick- eiiod along the median lino.

Height of hasal cup almost one hall' the length of the radials, its upper edges very thin, and overlapping the lower edges of the radials ; inlerliasd sutures oh.solete. IJadials ahout once and a hall' as hnig as wide; tin; side.s parallel or very slightly constricted at the lop and l.oltom; the lower lace convex, the U|)per angles .scaic(dy truncated. The lower lacrs ^)^ the radi.tls and the upper faces of tho hasals in some; specimens coiiliiin tootli-liLe pro- jections fitting into each other like int.'rlociung sutures. Uadial facets seiui- circnlar, occupying nearly half the width of the plates, and (illed completely hy the costals, which are suhtrigonal, with concave iipjier faces. Arms from ten to tw(dve to tho ray, comparatively short, rather thin, ami very little tapering. The arm plates moderat.dy short and .slightly waving. Piuiiiiles long and in close (;onta(d, hiteially. Of the ventral disk only the midiile plate of tho (irst interradial row has heen oh.served, which is comparativol v small and suhtrigonal. The two pro.vimal joints of the column circular.

Ifiri:r'ia mid A//<v(///y. — Lower IJuiliiigton limi'stoiie; lUirlington, Iowa.

T//pf in tho Illinois State collection, Springfield.

liiiiiiii-h:t. — This speci«!s was confounded hy Owen and Shumard, and also hy Meek, with I', ji/anif.'i, from which it dill'ers in the larger size, the proportionally much smaller and thinner arms, the projecting rim u{ the hasal Clip, and in the nndulaled hasi-radial suture lines.

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072

TUK t'UlNUIUKA CA.MKUA'IA OK NUinil AMKKICA.

Platycrinus graphicus TtAi.i, and Whhk. riatc LXXI. Fi,j. 7.

ISO:!. Ham. nml WiriTHiKi.i); 17ili llip. N. Y. Slnlc f/ili. Nat. Mist., p. 55; and 1875, Guul. .Sun. Oliio

Vi.l. II.. I'arl II., p. Wi, I'lair II, I'if,'. i. ISSI. W. and Si'.; Ili'vision, I'arl II., p. li (I'mirc-d, Acad. Nat. Sci. I'liila., p. iiKi).

Syii. /'. rirliliidilfiiaix U.M.I. and Wllil'l'.; IS(5, Cic(d. Suiv. of (Jliiu, Vcl. II., I'art II., p. HI?, I'lain

II, Kil,'. 1.

Hclow iiXMliuiii hIzc. 'iTio known Hpccinions of tlii.s species are Ijiully (M-ii.sIkmI, iuid it i.s iinpo.s.silile to give the I'orni and proportiun.s ol' the calyx, Itnt probably tiiu dorsal cup was moderately wliort and rounded at the banc. The plal(!.s are thin and without (jrnainentation.

Basal cnp apparently deep, its hciu^Iit beinj^ probably equal to half the l('n;;'th of the radials. iiadials wider tiian long, Hulxpiadrangular, thickened ill the middle, tiie iip|ii!r laces of the; limbs very slightly sloping, and but little excavated for tlu; facet, whiidi laces upwards, and occupies half the width of th(( plate. Costals ratiier l.irgc, the upper angle sliarply pointed, the upper sloping faces distinctly concave. J)islichals free from their origin, considerably narrower than the costals, a little longer tlian wide. Arms four to tli(( ray, rather didicate., tlie four or live lower joints wcMlge-lorm and alternatidy arranged, the siicc(!eding ones arranged in two sc'ries and sub- (|ua(lriingnlar; all joints moderately long. 'I'iie pinnules in adult specimens in contact laterally. Structure of ventral disk unknown. (Jolumn joints nearly cirinilar, angular around their (Mlgcs. 'J'he column is composed of r.'ither long joints, which alternate with shorter ones, from which we infer that this species ])osse.s.sed internodal joints.

Ui)ii::iin imd L'lculilij. — Siiales of the Waverly grou]), Kichfield, Snininit Co., Ohio.

TiJiii' ill the New York State Cabinet at Albany.

Ituninrhs. — Tiie specimen figured by Hall and Whitfield as /'. rir/iflil- dcns'tH undoul)t(!dly represents an immature sjiecimen of /'. 'jra/i/iiiitx. 'I'lie authors admit the strong resemblance of the two forms, but separate them upon the arm structure. They described the arms of P. rir/ijiihli)i>iis as being '•' composed of a double series of obtustdy wedge-form jilatcs in the lower [upper] part,* the sharp or narrow edges of which extend nearly

• The dcsrripliun s.ivs " luwcr part," wliicli obviously i» meant fur u;i/i,r pari, and "upper pari " In llic noxt line ffir /'>//•'■/■ jiart.

I'l-ArycKiNiihic.

G73

ncroHH the arm; in the uppur [lower] puit tlie iiriii iiliilfs me proportionally lonj,'cr, and extend cntin^ly acrosH, but Hepiiratiiij,' veiy .slightly the (wo iidjiieent pliite.s on the opposite side, making a Hingle range of plates, with their longer faee.s alternately on opposite Hides. " Thi.s is (exactly the con- dition of the arms in every young I'Uilijr.rliMii when it enter.s the bi.seriul Htago.

Platycrinus Sampsoni s. a. .Mn.i.iat.

riiiir Lxx. viij. 10.

lS'.tl. S. A. Mii.i.Kii; (ji'i.l. Siiiv. MisMiuri, Hull. \, p. i:i, I'liclc 1, I'ii-. 11.

A Inrgo species of a very unusual form. Dorsal eup cylindrieal almost thronghout its full length, perhaps a little narrower at the upper end ; tlu; base !)roadly truncated. Plates thin and smooth, the suture lines very slightly grooved. The has.al cup resembles a very low disk with nearly erect sides; it is very broadly truncated at the bottom, the sides slightly expanding; the u])per laces form an idmost straight lino around the cup, the angles being so obscure as to ho sciirc(dy pcM-cejjtible ; height of the (;up ecpial to a little more than one third the length of the radials; the inter- basal suture lines barely vi.sible. Hadials of unecpiid size, some of them much wider than others, the widest ones about once and a half as wide ns long, th(! Tuirrow ones almost twice as long as wide ; the sides parallel, placets surrounded by a projecting rim; they are narrow, moderately deep, and dire(^ted ujjwards. All othcir ])arts unknown.

Ilnrir'.dii 'hill /.iirn/i///. — Up])er Murlington limestone, Hurlington, lowii, and Sedalia, .Mo.

T,'//ii' in the collection of Mr. Sampson.

Jtniiiirka. — Described by Miller from a natural cast, but the species is so remarkable that it is readily identified. We possess of it a ne.arly [jcrfect dorsal cup from which our description was ma<le.

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074

THE CKIXOIDEA CAMERATA OF NORTH AMERICA.

Flatycrinus cequalia Hall.

r/d/e LXXI. Figs. ^«, b, and o.

1801. IIat.i. ; Desor. of 'Acw Sppo. of Crinniils, p, 17.

lS7:i. -Mkkk iiiul WoiiTiiEN ; (in.l. Ui-|.. Illinois, Vol. V., p. 456, riiite 3, Fis. S.

ISSl. AV. mid Si'. ; Uevisi.ni, I'ail 11., |i. 70 (I'locral. Acad. Niil. Sci,, riiila., p. H\).

Svu. P. biiliolft S. A. MiLLEU i Gcol, Surv. Missouri, Bull, i, p. ii, I'hilc 3, Tigs. 1 niui 3.

Calyx of nicdiuni size, the arm.s {)i'oportioniilly long. Dorsal cup bell- shnpcd, rouiuliiig below to near the colunni facet, which is distinctly elliptic and .''omewhat protuberant, giving to tiie sides of the base just above a siiglitly concave outline ; the radial.s a little convex, and more or less spreading to the facets, which are surrounded by a thickened rim. Plates a little thicker than in the preceding species, moderately convex, and with- out ornamentation. The ba.-^i-radial and interbasal suture lines generally fonr.ing broad, sliallow depressions,

Tia'-al cup deep, its height about two thirds the length of the radials, somewhai quinquelobate as seen from below, a little bulging in a radial direction, depressed interradially ; the upper margin slightly beveled, pro- ducing a moderate constriction along the suture line. Eadials quite thin at tlieir edges, tiiickened in tiie middle, a little longer than wide, and usually wider at the upper end than at the lower ; the sujjerior angles slightly trun- cated. The facets subquadrangular, deep, rather long, their width equal to one hidf the transverse dimension of the plates. Costa's trigonal, very small, occupying but one third the width of tlic facets, which enclose one or l)otii distichals. Distichals and palmars twice as wide as long, free above their first plates. Arms varying from six to ten to i!-e ray : long, widest at the middle, gradually tapering to the tips, the dorsal surface somewhat flattened. Tbe three or four proximal arm pieces cuneate and singly arranged, the biserial ones above .shorter and present'ng a curious flexure or genicula- tion in tlie middle, so as to give a zigzag appearance to the transver.se sutures between them. Pinnules in close contact, and composed of joints three to four times as long as wide. Ventral disk unknown. Column elliptic, ;ho long diameter of the joints more than twice as great as the shorter one.

ILiriznii and Lom/iti/. — Upper Burlington limestone, Pleasant Grove, and Burlington, Iowa.

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^

.-.% -If

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'M

n :•

ii

rLATVCRIXID.i:. C7"j

Tuiic in the Museum of Coinpiinitivo Zoiilogy.

Itanwks. — Tlie peculiar form of tlie dorsal cup, the elliptic projecting column facet, combineil with the ann structure, distinguish this species readily from all others known to us.

TRUNCATULUS GROUP. Plates without ornamentation ; costals two.

^

Platycrinus truncatulus Hall. Plate LXriI. Figs. 11a, h, and Plate LXXI. Figs. lS<t, h.

1S58. Ham.; Goul. Hep. Iimii, Vul. I., I'lUl 11., ].. olis.

ISSl. AV. mid Si'. , Kcvisidii, rrirl II., |i. 73 (I'rocml. .Vend. Nut. Sci. I'liihi , \\. 3Hi)-

A small species. Dorsal cup basin-shaped, more than once and a half as wide as high, broadly truncate at the bottom, the sides slightly' conve.\ and moderately spreading. Plate.s heavy, considering the small size of the species; surface smooth ; suture lines not grooved and difficult to see. Arms unknown.

Basal cup very .shallow, only the >ipper angles and the e.xtrcmc upper margins of the sides visible in a si<le view ; these curve abruptly upwards b}' a sharp angle ; the lower face perfectly Hat, except that the cohmm facet is surrounded by a small circidar ridge; the intcrbasal .suture lines somewhat eievated. Radials one fourth wider at the upper end than at the lower, the width of the lower face equal to the length of the lateral faces, the ujiper angles distinctly truncated. Facets narrow, semicircular, the excavation limited entirely to the outer edges of the plates, the inner edges forming a straight line. Costals two, the lower plate shorter than the upper, twice ns wide as long and quadrangular, the upper one hex.igonal, its upper angle truncated, and the distichals separated b}' a wide gap. Distichals two, as long as wide, the second axillary indicating another division above. Ventral disk slightly convex, the plates almost flat. Orals rather rcgtilarly arranged, and small. The ambulacral piece.? rising above the general level ; very narrow, small, and as regularly arranged as in an}- of the recent Crinoid.". Interambulacral plates numerous ; the first of the regular sides very large, its .sides resting against the first costals, the two at the .sides, which in this species are extremely small, touch but slightly the second ; the plates above very minute. At the anal side there are three plates abreast ; the middle

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C70

TlIK C'UINOIUKA CAMERATA OK NORTH AMERICA.

I

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if' u

one nanowL'r ami .shorter tlian the corresponding plate of the other sides, the adjoining ones a little smaller. The snccceding plates are small, and form a tubular inliation wliieh contains the anus. Of the colinnn only the six proximal joints have been observed, all of which are circular.

Iluvhun iiml LiicaJ'ttij. — Lower Burlington limestone, Burlington, Iowa.

Ti/iic in the (Worthen) Illinois State collection, Springfitid.

liaiiarliK. — Tliis and the succeeding .species diiler from all other riatij- crini known to us in having two costals. That this is not an abnormity, but a constant cl-.aracter in this species, is proved by the fact that we observed the same thing in four specimens and in all the rays. The species also departs from others in having but one interradial in contact with the radi- al.s, and the stem joints are apparently circular. If we were certain that the latter structure also occurred in P. eriensis, we should propose for the two species a new generic name.

Platycrinus eriensis Hall.

ISfia. Halt,; ISIli Hop. N. V. Slate Cab. of XaUinil History, p. 119, Plate 1, Fig. 1.

A small species, the dorsal cup scarcely more than 5 mm. in height, the arms three times as long. Ba.«als anchylosed, curving gently upwards ; the column facet comparatively large, bordered by a thickened rim. Kadials a little wider than long, slightly spreading ; the interradial sutures marked by a sharp line. The median line of the pltites more prominent below the facets. Facets nearly one third the width of the plate. Costals two, the first (piadrangiilar, the .second pentangular, giving off two simple arms. Arm joints uniserial, as far as preserved, .strong, subangular, thickened at their extremities, and supporting strong pinnules. Surface of plates granulose. The strong subangular joints of the arms, and the strong pinnules, are marked characters.

IlirLvon ami Lucality. — In the shales of the Hamilton group, near Ham- burgh, Erie Co., N. Y.

Tiipc supposed to be in the N. Y. State Cabinet of Natural History, Albany.

L'vmad's. — To judge from the arm structure, the description was made from a very young specimen ; but it is interesting as having two costals like P. tnincatulus. Our description is made after Hall.

f

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I'LATYCUIMD.K.

G77

9

I

SAR^E GROUP.

Tlio plates of tlio dorsal cup smooth or ol)sciirfly gramiloso ; tlio inter- basal sutures raiscil into ridges hy excessive secretion of calcareous matter during ancliylosation ; the stem with internodal joints.

Platycrinus Sarse ilAr.r,.

Plate LXIX. Fhj. 7, awl P/atv LXX. Fi</. 1.

Iv.'i. Ham.; (In.l. Hep. [(avu, Vol. I., Piiii II., p. i;7;i, I'hiiu Is, Kig. t. IbSl. W. iiiul Si'. ; Ucvisilill, I'urt II., p. 71..

Syn. riiili/niiiKs ilmnjei, ll.\l.i.i Siippl. (!coI. lic|), Inwn, p. 82.

Syii. /'. i„;ill,i„i„i!s M. .111(1 \V. ; (n(,l. Kep. IlliiidU, Vol. 11„ p. 2iU, riate 20, Fig. 2.

Syii. /'. moiiiwii'i.i WdliTllK.v; Mi/., Veil. VII., p. ;i()f>, I'liilc W), l-'ig. 9.

Dorsal cup goblet .shaped, gibbous in the middle, broadly truncate ot the ba.so. Surface of plates smootli, or covered with a few obscure ridttes na.ssin<' out from tiie fleets to I lie lower angles of the radials.

Basals forming a .saucer-shaped dish, occupying fully one third the height of the dorsal cup ; the lower end broadly truncated, the outer margin pro- jecting and forming a rim ; the lower face a little concave, and wider than the upper stem joints. Interbasal sutures distinctly elevated above the fen- eral surface, and formed into ridges, liadials quadrangular, as wide as long, and as wide at the lower end as at the upper. Facets deeply indented, em- bracing the costal and one or both distichals. Costals very small, triangular. Distiehals once and a iialf as wide as long, giving off an arm to the outer side of the plates, their inner sides two palmars with two arm.s, making .-^ix arms to the ray. Arms biserial from the second or third joint, of moderate size ; the tips somewhat tapering. Pinnules very long and closely set ; their joints more than twice as long as wide. Structure of the ventral disk un- known. Column very slightly oval ; composed of nodal and internodal joints, the former wider and higher than the internodals. Whether the upper and lower faces of the joints have transverse ridges could not be ascertained from the specimens.

Ilorkon and Localiti/. — St. Louis group ; St. Louis, Mo., and Jersey Co., 111.

T>jpcs in the (^Yorthen) Illinois State collection, Springfield. Remarks. — P. Sara- was described from a very large, somewhat crushed specimen, showing indistinct traces of ornamentation ; P. Georrjii from a dis-

078

niE CKIXOlDlvV CAIMI'.HATA Ol" NOlflll A.MIliK A.

M

\U

I ' i.i

1

tortetl, iiiiieh snmllur specimon, willi .siiiootli jjliili.s. In iliu Ivjiu of P. jnnt- kiiKiiiO', whicli preservL'd its iiatiiral loriii. tiie lini iiruiiiiil tliu base iii'uji.'cts inoie tluiu in llio t\ pe of 7'. Sara- as liyiuvd 1)V Hall, but tlio base is not correctly reprcsenteil in that (iyiue. 1'. innHi'iH'ii.sii is a ver}- ^oiing speci- nicn in which the arms are as yet uniseiial, '/igzag, and the plates wedge- Ibi'in, with nothing to indicate that it dill'ered Iroui the jneceding rmnis.

Platycrlnus HuntsvUlsD iHnc.si .Ms. Plate LXXIH. Fijs. 0, 7<i, f>, S, .'), JO. IL 12.

1SI9. Tuoost; I'rooci'd. .Vniir. .\ms. .\iIv. Si'i. nf l^^y. p. 01 (HitlKiiil (li'>ori|iliiiii).

Svn. Vl.ili/cfiiiic iifiiifilliit M. mill W.. l^'iO; I'l'iicci'd. .\mA. Nut. Si'i. I'liil.i., ji, liSO ; iilso (Icnl.

Ilcp. Illiluiis, Vol. 11., II. m\, I'llili' HI. Kl!,'^. (•«;, li.r. Svii. I'ldljiiviiiiii ji/e^iiin .\1. uimI W., Isiii); I'riipi'i'il. \vmI. Nut. Sci, riiihi., p. 'M); ulsuCiciil. l!e|i.

llliiiiiis, Veil. II., p. SCi?, I'i.iti' 21), V\if. W. Svii. I'lii/i/i-riiiu.i (iliilniiiirima S. A. MlLLKU, 1^'Jl ; Adv. Sli:cl> Ulli liip. (iiul. Siirv. Iiiiliiimi, p. uO,

I'liili.' y, Fii,'. a.

Ai, extremely vjiriid)le .«peeies ol' the ty|)e of P. Sunt, varying consid- erably in the ibrm and orniimentation of the cidy.x plates and in the nmidjcr of arms ; but readily recognized by the peculiar iind unique Ibrin of the brachials, imd the presence of ii large piniiide up(ni the first distichid.s and first pidmars. Dorsal cup generidly a little wider llitin high, cup or bowl- shaped ; the sides in most of the specimens nearly strtiight, curved longi- tudinally, but sometimes distinctly convex and constricted tit the arm regions ; bit-^e ol' the cup rather broadh' trunctited.

Uiisids forming ii short saucer-shai)ed "uj) with a flattened or .slightl}' eonciive lower ftice, which exceeds the width of the stem at the upper end ; the interbiisid sutures visible by moistening the specimens, tlieir lines highly elevated above the surface, and formed into ridges which at the lower e<lges of the cup ternuuiite in smidl tubercles. Rtiditds subcpiiulrangular, tibout as wide us long in nniture specimens, proportionally a little shorter in the younger ones; the sides very slightly cxptinding; the .superior Jatertd angles distinctly truncated. Facets directed upwtird ; small, occupying only one third the width of the plates, and extending but a short distance downward. Cos- tals trigontd, much wider than long, occupying the full width of the facets ; the superior faces concave, tiiid indented at the median portions for the reception of small proces.ses passing out from the lower edges of the di.s- tichals, and forming waving sutures, which resemble those of the Ichtii^'o- crinidtc. Similar suture lines occur between the distiiduds, ptdmar.s, and

m

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I

PLATYCRIXin.E.

(179

f

"I

,4

between tlio (ivo or six proxiiiml pliitcs of tlio nrnis. Distidml.s two, tliici'tud upwiirtlH, ratluT liirao, tlio first nvavly oiirc luid a linlf iih wide as long, nnd pinnule-beiirinn' ; the .second a little longer nnd axillin'y ; their upper angle.s ncnt«. The di.stiehal.s generally support a single arm on either side ; occa- sionnlly, however, one of the plates — or both of them — gives oft' an arm from its outer side, and two palmnra with two arms from the iinier one. The two palinar.<<, when represented, are as large as the distiehals, hut proportion- ally higher. Arms free above the first disliolials, from four to six to the rnv, the lunnber often varying in the same specimen ; rather heavy, especially at midway, where in adidt specimens they are often twice, and even three times, as thick as near the calyx. They are biserial at the upper end, uni- serial to the fifth or sixth ji.int ; the hitter phites, which are moderately long and wedge-formed, are alternately arranged and gradually interlock. The distichals and the cunoafe arm pieces are constricted in the middle, and pro- vided laterally with sharp, thorn-like projections at their upper and lower ends, which sometiines extend to the biserial portions of the arms. Pin- nules stout, long, closely packed, and composed of long joints ; the one from the first disticiial stouter than the rest, and less erect. Of the ventral disk only the middle jdate of the interand)ulacral series has been observed ; it is visi!)le in a side view, and crowned by a small tubercle or short spine. Stem joints elliptical and moderately long; the nodal ones nt the lower part of the stem quite prominent, and their margins in well preserved .specimens sur- rounded by bead-like nodes or short thorns.

IIorhoH iiwl LoralUi). — St Louis limestone, Ilunt.sville, .\la., and Hardin Co.. 111. At Ilunfsville it is found about sixty feet below the Paifmid/cs Gixl'iiii beds, where it occurs in small pockets in large number.s. Ti/pcs in the collection of Wachsmuth and Springer. fk'fiinif/.s. — The nnmo Plafi/rriiws Hitiili^vlllai appears in Troost's List of the Crinoidea of Tennessee, ptddished in the Proceedings of the American Association for the Advancement of Science, Cambridge meeting. 18-10, witii- out figure or description, and has ever since been applied by palaeontologists and collectors to the only form of PM,/criiiiis occurring near Iluntsville. AVo are aware that this does not establish Trooft's name.

In 1860, Meek and 'Worthen described as P. pcnicUlux and P. pJcniis two specimens from Hardin Co., 111., both of which we have examined, and which we have reason to regard as aberrant forms of P. Iluntsvilla. Looking at the two specimens alone, one would say at first sight that they are distinct

cso

Tin: {'KINOIDI'.A C'AMI'.llAT.V Ol" NOlMIl AMI'.WK A.

«

1

I

ppccit'«, mill iliniTent IVcuii /'. J/nnfxrllltr ; liiit iiiinii examining tlic iiini structure, babuls and Htmi, it will Iju rouml tiiiit tlnv (IjlTi'r only uliglidv in tlic form of the oalyx ami tiio matter of oinMini'iitalioii, one IxMiig cnp-^^liaiu'd and ornamonti'd, the oilier glolndar and smooth. On eompurin;;' tlii'm wiili tho specimens from llimtsville, it will ho seen that similiii' viiriiitioiis oeeiir among them nlso, along with all sorts of transition loriiis. The two lomis were evidently regarded by Meek and Worthen as spceilieally distinet licmi /'. Iliiiitsrilhv, for the Worthen eollection eoiitains a large nmiiher of fine specimens from Alaliama, labeled /'. IfitiitKrilhv.

In ISOl, S. A. Miller described nnder 1'. (iliihuiiiiiisis a small, crnshed speci ncii from Ilnntsvillo, but neither (igure nor description gives a correct idea of tho species, and he did not state in which division of the " Snbear. bonifei'ons rocks" it was found. He did not define the peculiarities of the arm structure, which are so characteristic of /'. //iiiifsrilke, and indeed tho description would apply equally well to otiier forms. It is very curious that Meek and Worthen described the arm structure, but did not represent it in their liguro ; while on the other hand Miller indicated it in his figure witli- out mentioning it in the description, Priority would give the first of Jleek and Worthen'8 names to the species, if any of tho above descriptions are to apply; but this would lead to confusion, and would establish an aberrant form for the typical one. Under all the circumstances, we have tlKuiglit best to redescribe tho species under 'I'roost's name, thus giving the credit til the iiionocr naturalist who discovered, recognized, and called attention to the new form.

For the last ten years one of us has spent a month or two every year at Huntsville, and obtained of this species over a thousand specimens, in all kinds of preservation, and of all si/.e.s, from 0 mm., including arms, to ."■lO mm., and intermediate stages, which give most valuable infoinialion ii]ioii the variability of this s])ecies and the Crinoids generally, and also upon the changes due to growth. If wo were following the practice ot some ])a];i'ontologists, we would ho able by ])icking out individual speci- mens to Tiiake out of this one species half a dozen or more. In some speci- mens the plates appear altogether smooth, without showing in other j'arts an}' evidence of erosion or weathering; while others have well marked nodes, separate or confluent. In still others the proportion of height to width of the calyx varies considerably. All these s])ecimens, however, are character- ized by certain peculiarities by which they can bo identified nt once as be-

I

I

i

I'Latvcuinmdj:.

(isl

'6

l()?ij{ing to ono Hpoeii'H. In all of tlicm there appear nmuiul llic sdni ilnue coiiHpicuoUM iioilcH, wliicli aiu cuntiiiucil to tlio upper edges of (In- lia^al (li>l\; and in all may lie i^een llie uni(|iu' arliculalion liutwccn llie lowei' InacliialH nnd uini platen ; while the inllation ol' tlie arms at their middle purtionn is a lVe(|\ient eharaeti-r in mature .specimens. Hut far more striking' are the dif- CerenceH caused \>y ^Towth. Comparing the snadler speeiniens wiih the hirger ones, it will he loinid liiat the arms in the smallest or youngest ones are not o)dy uinserial throughout, hut decidedly zig/ag, and that their joints are proj)ortionally much longer than those of the adult In more advanced Hpecimens the tips of the arms are hisi'rial, and the liiserial part extends downward, as the specimens grow larger, by tlie introduction of adilitiomd joints at the top, and the ]irogressive interlocking of the cuneate plates. The modificatiouH here exhihited, and due beyond all rpu'stion to individual growth alone, are so renairkahle, that without a knowledge of the ontogeny of the Crinoids, the earlier stages of this species might readily he taken as representatives not only of dill'erent genera, but even of difl'eient groups.

Flatyorinus boonyillensis s. A. Mi run. Plate LXXII. FI(jH. S,i, h, ,01(1 !).

I'^ni. S. A. .MlM.KIi; Hull, 4, In.l. Siirv. Mi-suuii. p S, \'\nW I, l'ii;«, 1 mid 2,

A rather large .•species of the type of /'. hi/r/iiii/tniiriisin. Calyx to the top of the radials bowl-shaped, wider than high, slightly pentagonal os set'U from above. Plates moderately heavy, the sinface smooth, or nearly so; the hasi-radial and intcnadial sutures grooved. IJasals closely anchylost'd. the lines of union elevated into ridges ; they form a low. rapidly spreading basin, distinctly pentangidar at the ujiper end, broadly truncateil at the lower, the bottom deeply excavated so as to form a rounded, rugo.so rim around the column. Column facet circular, occupying one half of the width of the concavity, its face covered with radiating stria\ Radials a little wider than long, gradually expanding upwards, slightly nmre elevated along the median line, and somewhat beveled toward the sutures. The facets occupy less than half the width of the plates; they are shallow, directed upwards, and surrounded by a projecting rim.

IlorUon ami Loraliti/. — Lower part of War.saw limestone ; Boonville, Mo., and Spiu'gen Hill, Ind.

Tiij^es in the collection of Mr. Sampson.

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682 TUK (UINOIDKA ( AMKHATA Ol XOIMII A.MI.ItlCA.

IliiiKiihs. — I)(.'.-<('iilj('il I'iDiii till' )mi.'<iiU ami railiiil.'^, all tin' iitliiT |iarlH Ih'Iii^ uiikiiuwii. Tlio iiiti'i'liaHul i<iitiit'i'.i, whicli ari> ivproHi'iitcil in Imili nf Milii'i's Cij^iircH. lire 111)1 vixililo in llic i-iu'i'Iiiu'Iim ; Imt tlio pliiceH wlieiu liny hImmiIiI bo are indicutod li^' ulcvali'il ii(l(',i'H.

PlatycrinuB niotonBls M. ami w. l'l,il, LXXl. Fiij. !).

ISflJ. MkkkiiimI WniiriiKSi I'mcT,!. Anul Nut, Sri I'hilii , p. Kli; niul firnl. II, 'ii. Illiiici", Vul. FII.

ii. SIM, Kitf. ;i.

bSl. \V. nil, I Si'. , U,\l,i,iii, I'liri II , |.. ;:i (I'lurci'il. Afiiil. Xiii. Sci. I'liilii., |i, i\7).

A very tunall Hpecics. Calyx Ih'Iow the miniinit of tlio rndinlH cnp-

uliiiped. the nides di.-'tiiiclly nnmdeil in the type, scareely eoiivox ill other Hpeciineiis ; the liiise short. Iiii^in-shaped, hi'oadly trniieated at the boltoni. l'latu'< Miiiuoth and sli^^htly eoiivex, the hasj-rnilial and iiiterradial xutiireH distinct, but not jfrooved.

liasiils ioiininjr a short enp of one third tlie lieij;ht of th(> radials, the lower rim somewhat projecting; outward, the lateral margins of the plates «lij(litly raised toward the suture lines, and forminj^ indi-tinet ridjrcs and ii umall projection at the lower extremity of each suture. Ivailials larife. as loni^ as wide, or a little longer, widening moderntely from below upwards; sulnpiailranguliir. tlu^ superior iiugle slightly Iruncated by the iiiterradial pliites. Facets shallow, nnil occupying about half the width of the plates. Costals trigonal, rounded at the lower end, completely filling the liicets. Dis- tielials two. both one third wider than long. Arms four to the ray, rather lienvy throughout, and biserial from the second or lhir(l plate. Column near the base compressed and tortuous, being composed of alternalu thick and thin <dliptic joints.

Il'i-hiii ami Luriih'ti/. — KeokuU group; Niota. III.. Indian creek and Canton, Inil.

T'lpi' ill the Illinois State .'jllection,

Itcmiirkii. — The figure of the typo specimen in the IlIlnoiM Report i.s somewhat nii.slending ; the base is made too high and the radials too short. It also ajipcars as if one of the rays had but three nrins, while it actually has four, like the other rays. The species is closely allied to 1'. Sura; but is considerably .smaller, and its arms less numerous and jiroportionally stronger. It resembles still closer P. bonocnsis, but that has five to six arms to tlio ray, niid the arms are shorter.

J

II

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I

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l'LATVCUIMI»-K. 083

Platyorlnua bonoonsli U'iutk, I'hk LXIX. I'iij. (1.

b7t. WiiirK, I'rncml. Anui. Niil. ^f\. I'hiU., |<. ;i'l; iiiul l-^il, I', », (muI. Siirv. 'IVrr. bj llii^il.n,

C.Miir. lo I'lilii'iMit Nil ri, |i. Kill, I'liili' ID, Kit( 5. llSl, W. mill Mr. ; llrviMiiM, I'liil II , |i. ',» i I'r nl. Aniil, Niit. >*ri riiilii.. |i. i\\).

Ifl;ii. l>,iHrfmilh». A. Mll.i.Kii. I><lll ; (ir'il. Siiiv. Mi^hmiii'J, Hull, t, |i. ||, I'liili' j, KiK- 8.

Hjfii. /'. iW«''(i< it. A. MiLLiii, WJi , Ailv> bliiili I'liil \W\>. Utul. fiirv, nr liiiliuim, p. 13, I'luli'

n, KiK. i;).

Clo.ioly iilliod to tlio preceding Mpeciex, hut Imvinj; five to xix nniiM Id tin' ray iiiKleiid nf four, and lliese uro |)i'o|i()rli()iiidl_v ^linitci, iiinrt' clofiidy piickcd, and licaviiT. Doi'muI (Mip wider tlmn liijili, lM)\\l->lmpud, a iitlli' sprt'iidiii;,'. llic iMai'giiis ol' the plaU'M Mli^litly licvcli'd, giving In liie ccnlial puitionx a ^iigiit coiivoxity. Snrl'ace witliont ornamentation.

llasaln proportioniliy KniaJl, forming a hIiuIIow liaHiii. Iiroiidly truncated Im'Iow and excavated at liio liottom, liie siden .somewhat con.-tricled ho as to liirm a rounded ])roiecting edge aroinid liie louer margins; llie interlinsal tituie lines slightly elevated. Ihidials wider than long, gradually expanding iipwanls, the upper angles truncated, deeper at llie anal side. Facets iVoui one half to two thirds the width of the radials ; semiciicular. Costals siuiill. trigonal, rarely covering the full width of the facets, and the distichals ahut ngainnt the radials. First dislichals oiu'c anil a half as wide as long, the axillary one a little wider ami somewhat higher. The latter gives olT an arm to the outer sid(^ of the ray, and HU|)ports at the imu'r two palmars with two arms, luakiiig thri'e arms to ciudi sididivision. or six to the ray. excep- tionally five. The arms arc stout, especially in the middle, aiul quite short ; they are uniserial to the fourth plate, lu'vond this hiserial. Column slightly elliptic, and twisted.

Jlorlziiii mill Lnriilifi/. — rppeimost part of the Keokuk group and lower beds of the Warsaw limestone. Hoiio. Lawrence Co., Ind., and lioonville. Mo.

Ti/iicx in the collection of W. F. V,. (Imley. and R. A. Blair nt Sedalia, Mo.

sunspiXL'L OS us a no up.

Basal cup ainmst as high as the radials, aubcylindrical. Surface of plates smooth or ornamented.

r

ill

\

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>n

684 Till". ci{IN<mi)i:a camkkata ok nouiii amki.!' a.

Platycriniis siibspinulosiis Hai.i.. y '/,(/-■ I.X\I. l-'iijs. J,i, /-. ,111,/ I'M,' I. XX. F!,j.!).

\'<M. II Ml.; Siip|il. (n.il Ki'p. In\i:i, p. SI, Willi ili:ii;raiiini:ilic liirnri'.

Is^l. \\ . .111.1 .^r. 1 Ki\i>luu, I'ail II , y. 75 (I'loiciil. Ai-id. N;.l. Sci, I'liilii , p. 211).

l?fli>w iiu'diiim si/.o. Ilci^lit of dorsal ciip about equal to flu- width nt the lower I'dj^a's of tlic radiiil I'liccls, vlicrc llit' ccclion is disliiiotly (|iiiii(|no- lolialo. owiiiir lo a tliickonini; ol' tlu> radials at tlu< inodian liiu> toward tlic fai't'ls. Plates tliiii at llicir i'(li;es, 1ml (iiiile liea\_v at tiie middle ; covered with short s]iiiies or ('(Hispieiioiis nodes, wliieh uiioii tlic basal cup are (luito in(>i;'idail_v distributed, some of them beinu; thieklv set and poniliient, other.s dispersed, especially in the iipju'r portions of the cup. The spines upon the radials are arranj^ed in thi'ee rows, two of them proeeedinij; from the facet.s diaitonallv to the lower aiiifles of the olates. the other vertically to the basal ciij). liiterradial sutures at the bottom of a shallow angular depression, not j^rooved ; iiiterbasal sutures obsolete.

JJasal cup subcylindi'ical, a little widest at the ujiper end ; the colunni facet projectinj.' and distinctly elliptic. IJadials slightlv spreadinjr. nearl\' once and a half as lon^i- as wide; the facets horse-shoe shaped. Ion j;'er than wide, profoundly excavated, and havinsj; a deep, rounded notch at the ujiper end. Structure of arms and ventral disk unknown.

J/iirir.iin Kiiil l.<ii;ililii. — I'pper IJurliufjton linu'stone. Burlington, Iowa.

T;ijii in the Illinois State Mu.seuin of Natur.'d Ilistor}'.

Platycriniis Davisi w. .iiul Sr. (nnv. ^hv.).

i'i,ii,' i.xx. Fi.i. /;.

Below medium size. Dorsal cup de|)ressed bell-shaped, a little wider than high, rounded at the base, the sides concave along the basal cup. con- vex along the radials. Plates rather heavy; the suture lines very slightly grooved.

Mas.il cup deep, wide at the bottom, its height equal lo two thirds the lenglii of liie radials. its lower face (piinquelobate. having five short, rounded nodes, iiiterradialiy disposed and extending over the whole width of the plates; they are separated by a Well delined groove, giving to the base the appearance of being (piinqiiepartite. Attachment for the stem circular and

I'Latychinid/t;.

f.sr,

^

r

slightly (lopresscd. Riuliiils inotlenUcly .s|in'!i(linj,' mid soiiu'wlmt irrcgiiliir in loriii ; tlio two postt-rior oiios fully a,s wiile iis loiijr, the othcr.s a liltlo loiigiM-; tliu iiietliiin portions of the pliites abniiilly riiisi'd, lorniing n ((niid- rangidar elevation of whii-h the niargins are parallel to the edges of the plates. Costals siihtrigonal, rather short. Ventral di.sk convex, llatlcned at the sinnniit. The orals very large, the posterior one larger than the lour others; the latter elongate, at the four regular sides of the calyx resting against the lirst row of interradial.s, of which the middle one is wedged in deeply Iielween the radials. The middle plate of the anal side is miicli wilier, and supports a niunl)er of small plates which forsu the anu.s. And)u- lacial plates few upon the disk. Anrl ojicning exccntric, directed upwinnls Structure of arms unknown.

//(//■/•..)« Kii,/ J,iiriillli/. — Lower Burlington limestone, Hannihal, Mo.

Tiipc m the collection of Wachsmuth and Springer.

Unnarka. — This species resenddes /'.siilis/iiiiii/nsKfi Hall, hut difl'ers in the Ibrni of the calyx and in the surface marking.s.

The specific name is in honor of Rev. .lohn Davis, of Louisiana, JIo., to whom we are indebted for the type .specimen.

Platycriniis allopliylus s. .\. :\iii,i.i:rt. J 'Mr LXXI. rill. IT.

ISni. S. A. Mii.i.Ku; Hull. \, (iiol. Surv. Missduri, p. 9, I'lalc 1, Ki^-s. H iiml \.

A small species, in its form nnlikc any other P/nh/rninis. Dorsal cup .slender, once and a half as high as wide, cylindrical to the top of the hasals, then expanding gracefidly to (he arm Cacets; the lower face hroadly (nmcalcd. Sin-face of plates apparently smooth; their margins toward the hasi-radial ami interradial sutures slightly hevcled ; the interhasal sutures rarely visible. Hasals as long as the radials. forming a cylindrical cup with a short expanded rim a'ound the lower end. the bottom truncated, and -slightly im])re,s.scd Cor the reception of the lir.st stem Joint, which occiijiies less than half the dia- meter of (lie lower face. Haiiials longer than wide, moderatelv expanding above, rounded along the back, depressed at the sides, their facets projecting. The latter occupy fully one half the width of the radials. and more than a third their length; they are semicircular, arc deeply notched at (he upper end, and directed outward almost horizontally. Costals short and axillarv;

ii

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686

TIIK CRIXOIDKA CAMKUATA OF NORTH AMKHICA.

the iiitcrradial plates erect. Ventral disk convex; covered with spinous plates. Column small, obscurely elliptical.

Horizon and Locality. — Chouteau limestone ; six miles southeast of Sedalia, Mo.

Ti/pci in the collection of Mr. Sampson.

AMEUICANUS GliOCP.

Dorsal cup rather short and but slightly spreading; base nearly flat; plates ornamented by coarse granules or row.s of conlluent nodes.

'■ I

Flatycrinus americanus o ami .Sii. Pktr LXXV. Fujs. 10, 11, 12, 13n, h,c.

\^'<i. OwKN aiul SlII'MviiIi; ('. S. (iciil. Siirv. Wisr., Iowa niul Minn., p. .T.U, Vl:ile 'ill, Figs. In, i. ISbl. W. iiml Sr.; Ucvision, I'urt II., p. 7^ (rincei'd. Acail. Nat. Sci. I'liila., |i. HI).

S.vM. l'lu/y,-r. Iniii.'iilii^ IIai.i.; (le.il. Kip. I.iwa, V.il. I , I'ail 11., p. ."ili;

CO Sjn. '/'. llm,„//i,;„/i .S. .\, Mii.i.Kli ; 1S'.)1. Onil. Surv. Mi>>uuri, Jlnll. 4, p. '21, I'lat.' i, Fii;. 15.

Calyx sul)glol)Osc, a little higher than wide. Dor.^al cup more than once and a half as wide as higii, sliglitly spreading, the base broadly truncated. Height of ventral disk about equal to that of the dor.sil cup. Plates orna- nieuted i)y coarse granuh's or irregular nodes, arranged in concentric lines around their margins, covering tlie entire surface. Edges of the plates beveled, and tiie basi-radial and interradial suture linos chanueli'd.

Basals forming almost a plane, rarely more than their beveled edi^e"' visible in a side view; the coluuui facet very slightly depre.-ised ; interbas- sutures indeterminable, liadials a little spreading, one fourth wider than long ; the outer ends of the upper faces moderately .^^loping. except toward tiie anal side where they form a deep and broad notch. Facet semicircular ; the notch at the summit very small, if rt'pre.xented at all. Costals rather large, much wider than long ; pentangular. Distichals and palmars as long as the costals but narrower, a little constricted across the middle. Arms six to the ray ; of moileratc size, biserial abo\ e the second or third ])late from the bifurcation ; the joints rather long ; the pinnule .sockets projecting, especially in young specimens, and the pinnules strong and in contact later- ally ; the proximal one being given off from the first distichals. Ventral disk hemispheric, the plates convex. Orals large, rather regularly arranged. Ambulacral plates small and not elevateil. ]nterand)ulacrals three and two ; the middle one of the first row longer than wide, that of the anal side much

K I

1

'>f:<fa«A.i^fc-.!.r.Mi.t

platycrixid;e.

687

larger, and wiiler than long, followed by numerous small pieces forming a protuberance, which is pierced Ijy the anus; the opening directed laterally, Column snudl.

ILnhon anil LochUIi/. — Lower Burlington limestone, Burlington, Iowa, Quincy, 111., and in rocks of the same age throughout Missouri.

JuiiKtrh. — Of this species we obtained several very joung specimens (Plato LXXV^., Fig. 11), in two of which the arms are as yet unisorial tiiroughout, in others biserial only at their tips. In these specimens the arms have a distinctly waving outline, their jjints are proportionally longer, sliaped lii\e axillary plates, and the sides supporting the pinnules are greatly projecting.

We have examined tlie type of P. (nniralii-i ITall, in the Illinois State collection, and regard the specimen as identical with P. (i)n(r!(((iiii><, although it has apparently no ornamentation. It agrees with the latter in tlio form of the dorsal cup, the channeled suture lines, tlie large and deep notch between the two posterior radials, as well as in the arm structure. Miller's P. Broad- hradi, in all probabilit}', is also identical with this siocies ; it was doscrilied from an imperfect dorsal cup, and neitiier figure nor description enabled us to make a critical comparison.

Platycrinus tenuibrachiatus -^r. m\A W. Plate JjXX. F'kj^. 7, S.

1809. Meek nml Woutiikx ; I'idociiI. .\™1. N;il, Sci. I'hilii,, |i. His ; .■mil ls;;i, Gcdl, Rep. Illinois, Vol.

v., p. 4.-ii», I'liilu ;i, Fisf. \u (nut \l.). ISSl. \V. .iiul Siv ; KcviMnii, l>;iii 11., p. 7.") (I'rneord. Aciiil. N.'it. Pci. riill;i.. ]i. 2+'.0.

Of medium size. Resembling P. amcn'canu.i, but the calyx proportionally wider, and also more discoid. Dorsal cup I)asin-shaped, three times as wide as high ; the base concave, only its upper angles seen in a side view ; tiio sides rapidly spreailing, very .slightly curving; basi-radial and interradial suture lines channelud. Surface of plates covered with rugose markings or irregular rows of nodular ridge.s, parallel to the outer jiiargins of the plates, and forming concentric lines.

Base largo, ratiier Hat; the median portion decidedly depressed; the inter'iasal sutures grooved. Radials uniformly spreading; the upper end nearly one third wider than the lower ; the sides a little shorter than the width of the lower face ; the upper angles truncated, forming a small but deep notchj which is filled by a liexangular interradial plate. Facets semi-

I

A ^

GS8

TlIK CRIXOIDKA CAMKUATA OF XOnTlI AMKRirA.

S

circular, occupying one tiiinl the wiiltli of the iilntcs. CostiiLs subtrigonnl, the sloping upper faces concave, and their angle rather sharp, Distichals and palniars once and a half as wide as long. Arms from six to eight to the n»y, of nearly uniform size throughout, biserial from their fourth or fifth plate ; the joints moderately long, united by slightly waving sutures. Pin- nules strong, composed of long joints. Structure of ventral disk iniknown,

Ilurizmt ami Ldcd/i///. — Upiier Burlington limestone, Burlington, Iowa,

2//j)C in the Museum of Comparative Zoiilogy.

Rvmarks. — In this species Meek and Worthcn included onother form, which we have described under the name of P/ii/'/rii'iiiis iiodoatriatiis, and which dilTers essentially in the form of the basal cup, and in the style of ornamentation.

Platycrinus breviaodus Hmi..

J'Mc LXX. /'/V/s. J, .7. (;„. h.

ISfll. Ham,; \l-in: New Spir. f'liM. |i. t, ;iii,l |i>.-l. .Imini. N:il. lliM., ji. 280; flixuml 1872, X. Y. Si;itc

Mubi'iihi, Hull. I, I'hto 2./, I'ii;. .'.. 1S81. W. :iii,l Si'.; HfviM.,11, l';irt II., [>. 7il (I'rocenl. Arail. Xiit. Sci. Pliila.. p. 2H).

A rather small species. Dftrsal cup nearly twice as wide os high, slightly spreading, broadly truncate at the base. Basids proportionally large, disk- like, truncate below, only the extreme upper ends turning upwards, very little concave, and the outer margins surrounded by a row of conspicuous nodes, directed outwanl and giving to the edges a crennlated outline; the interbasal sutures obsolete, Kadials wider than long, a little widest at the top; subr[uadrangul;ir; the outer ends of the upper face but .^lightly sloping, except tho.se of the anal side, which form a distinct notch, and sui)port a rather large hexagonal plate. Radial facets shallow, occupying half the width of tiie plates. Basi-radial and interradiid suture lines grooved. Cos- tals triang ilnr. moderately large, occupying the whole width of the facets. Disticlials two, free from the costids up, the first once and a half as wide as long ; the second as long as wide. Palmars, when present, but little larger than the succeeding arm plates. Arms fovu' to six to the ray in the same specimen, rather slender and tapering; their proximal ends composed of five to six cuneiform pieces, which gradually turn ir:'o biserial above. Piniudes placed somewhat distant. Structure of ventral di.-^k unknown.

JTorizon and Lora/lh/. — Described from the Keokuk group at Keokuk, Iowa; but occurring also at the same horizon at Indian creek. Montgomery Co., Ind., and in the Burlington and Keokuk transition beds near Burlington.

I'

ill

:m

i'latycrixiim:.

680

$

i

T//pe specimen in the Americnn Museum of Natural History, New York.

lieiHdrk's. — The Indian creek Hpceiniens sonietimu.s have an additional row of ridges pa^^sing out to the sides, hut otherwise agree with those from Hurlington and Keokuk. Their arms also vary from f(jur to .six to the ray.

Platycrinus canalioulatiis Hall. riate LXXV. Fuj». 7a, b.

Is.-iS. TIai.i.; fionl. licp. Iowa, Vul. [,, Vn\\ II., ]i. 5;!9.

is^l. W. iiiul Si'.; Kcvision, Pint II . p. 71 (I'md'eil Acad. Nat. Sci. I'liila., p. 215).

Calyx small, a little higher than wide, widest acro.ss the hase of the radial facets ; subovate, slightly truncateil at the poles. Dorsal cup once and a half as wide as high, the upper edge slightly inllectod. Surface of plates marked by a few rather conspicuous nodes, of whicli generally' twenty occupy the basal disk, two directed to each upper angle of the plate, while two others are parallel with the sides; the latter placed so close to the mar- gins as to give to tiie edges a serrated outline. Tlie radials have three pairs of nodes passing downward, two of them nnniing obliquely to the lower angles of the plates, the other pair vertically, following the median line. Two other nodes are placed close to the upper ends of the plates, one to each side. Basi-radial and interradial suture lines canaliculate, and the edges of the plates beveled.

Basals forniiug a flat di.sk, of which only the outer edges are seen in a side view ; the middle portion has a more or less deep rounded depression, wide enough to contain the top stem joint. Radials one fourth wider than long, very little spreading ; the upper angles .sligiitly truncated ; the facets semicircular, occupying nearly one third the width of the plates, thickened around tiie edges. Costals small, trigonal, their upper faces deeply notched. Ventral di.sk as high as the dorsal cup, distinctly stellate as seen from above. Orals small, rather regularly arranged, forming an elevated area from which the ambulacra pass outward aiul downward. Covering pieces .strongly con- vex, and conspicuously elevated over the interambulacral spaces, which slope abrupt!}' from the orals at an angle of nearly' sixt}- degrees, and form deep trigonal depressions containing three plates each : a verj' large and nodose lower one, and two smaller plates above. The two plates at the sides of the larger one are narrow, and curve abruptly outward. A nis and column unknown.

87

1

!fj

600

THE CRINOIDKA CAMKR.»TA OK NORTH AMKRICA.

Ilur'aon and Zonili/i/. — Lower Burlington limestone; Burlington, Iowa.

l]/jic in the ^Wortlien) Illinois State collection, Springfield.

Ji\in(ii7tS. — This species was described from a poor specimen, in which only the basals and railials were preserved. The markings of the type .ipeci- inen are less distinct than in the one we figure, but there can be no doubt that both belong to the same species. The form and ornamentation of the dorsal cup resemble very closely 7', brcriiux/ua Hall, from the Keokuk group, and it is doubtful if the two species are not identical. A satisfactory eoni- parison cannot be made as long as nothing is known of the structure of the ventral disk of that species, and in this nothing of the f.rm structure.

Flatycrinus asper ^l. and ^\'. Pla/e LXVIIL Flys. 9a, h.

ISfll. jrKEK mid Wouthf.x ; I'moml. Aoa.l. Nat. Sci. riiila., p. 120: nlso Gcnl. Tti'p. Illinois, V.pI. III., p. KiS, I'lule 18, Fi),'. U.

18S1. \\. ,111.1 Sr. ; Ucvisi I'uit U., p. 7ii (rroc.Til. Aciid. Xiil. Sci. I'liilii., p. i\\).

(Xi't r, iryit'r fidlilt'ii'^s =^Sfiu-fhinffinTini4s tin^fr).

Below medium size. Dorsal cup twice ns wide as high, gradually spread- ing, the sides nearly straight ; the base depressed, and abruptly and deeply excavated so as to form a narrow, thickened rim with an nndulatinjr or roui'li- ened surface. A similar rugose rim borders the lower and lateral margins of the radials. leaving a small quadrangular depression beneath the facet.s. Sides of the basi-radial and interradial sutures broadly beveled ; the inter- basal suture lines distinctly grooved.

BmsmIs rather large, only their outer margins seen in a side view ; the excavated iinier part considerably wider than the diameter of the column. Hiulials wider than long, widening moderately upwards, the lower face straight, the outer ends of the upper face .sliglitlj- ,«lopiug ; facet semi, circidar, its width eiiual to h.ilf the width of Uie plate, and .-lightly pro- jecting. Costals subpentangular. the slojjing upper faces concave. DistichaLs once and a half as wide as long, narrower tlnn the costals, an<l not in con- tact laterally. Palmars nearly as large as the distichals and of the same general form. Anus of medium size, four to six to the ray — six being [imbably the noruud number — composed above the a.xillaries of ."harply cuneate pieces, which gradually turn into biserial ; the costals. distichals, and palmars transversely grooved at the nii<ldle. Ventral disk iiigli. bulg- ing, composed of rather large, slightly convex pieces ; the ambulacral plates

i

I'KATYCiUNID.K.

601

small, slightly projecting near the arm bases. The intcramlnilacral spaces aiv formed of five plates, of which the middle one of the first row is twice as large as the others, and hexagonal. The two or three upper stem joints circular, the succeeding ones elliptic.

IIiii-i::iiii iinil Luntl'ihi. — Upper Burlington limestone ; Burlington, Iowa.

Ttipc in the Mu.seuni of Comparative Zoiilogy.

SCULPTUfi OllOUP.

Basals and radials forming a deep cup; the ba.se high and distinctly con- vex ; the plates ornamented by transverse lines of conllucnt no<les following the margins of the plates. Kadial facets small ; arms moderately large.

'4

-*»

Platycrinus sculptus Hsi.i.. Plate LXVJIl. Fhj. r,. wul Plate LXXV. Flf/. 8, !).

185S. IIm.i,; n.vil. |{o|). I.mu, Vnl. I., I'lirl II , p. yM\. IMiilc S, Kin. H.

ISSl. W. nnil Si'. ; Uevisimi. I'lirl !(., p. 7.". (rnicml. Acml. Nat. Si'i. I'liila.. ]>. 2V^).

Syii. I'liiii/i'i-iiim riiliialiit S. A. Mai.Ku; Uuul. Siirv. Missuuri, Hull, i, p. •'(), I'liile 2, Fiu's. U and 1:;.

Dorsal cup of mediiuu si/c, in very mature specimens higher than wide, a little wider than high in small ones, growing i)rop()rtionaIly higher with age; the sides evenly convex from the stem upw-ards. Surface of plates orna- meiiled with rows of conllucnt nodrs or undulated ridges, the base being covered by three to live rows, running parallel to the ui)per margins of the plate ; live others radiate from the column to the upper angUs. Similar rows, varying from three to six, according to the ago of the specimen, fol- low the uiargins of the radials, and three rows proceed from the facets to the lower face; two of these dii-ected diagonally to the outer angles, the middle one, which is sometimes unrepresented, placed vertically.

Base from one fourth to one third as high as the dorsal cup, basin- shaped ; the median portions slightly trnncated and a little excavated ; the upper margins of the plate somewhat beveled, giving to the basi-radial sutures a slight depression. Radials quadrangular, the lower edge convex, the sides very slightly sjireading. the upjier face but little .xloping to the angles. Facets small, .semicircidar, directed obliquely upward.s, occupying but one third the width of the plates, and only a small portion of their lieight. Costals small, trigoiud, sometimes narrower than the facets, so that portions of the first distichals come in contact with the radials. First di.s-

CM

TIIK CHIXOIDKA CAMKUATA OV NDUTIl AMKHK'A,

ticlmis sinull, twice as wide ua long, placed obli(inely, tlie two of the Hiiino vt\y connected Ititeriilly. Second diHticlials coiisidenibly wider tlmn tlie first, but not longer. Piihnars a.id po.st-palniars of the Ibrui of the distichaln, but somewhat smaller. Aruis eight to the ray ; cylindrical, moderately strong, biserial from the start; the upper edges of the plates forming a small thicivcned ridge projecting over the lower margin of the succeed- ing plate. Structure of ventral disk unknown. Column small for the size of the specimcMs, elliptical and twisteil ; the transverse articular ridge of apposed faces prominent, with a distinct fossa at each side.

Horizon and JjOcdUtij. — Lower Burlington limestone; Burlington, Iowa.

Ti/pc in the (Worthen) Illinois State collection, Springfield.

lionnrhs. — The ornamentation in some specimens is more conspicuous than ill others. The length of the radials and the depth of the basal cup are also i(uite variable. The latter, however, may be uuderstood by consid- ering that the rows of nodes surrounding the margins of the plates repre- sent lines of growth, and increased in number with age, and as the plates grew faster longitudinally than horizontally, they became in the older speci- mens proportionally longer.

This species, with slight modifications, apparently occurred also at Lake Valley. New Mexico. A specimen from that locality (I'late LXVIII., Fig. o) shows the structure of the ventral disk, which had not been observed in any from Burlington, but as the arms are not preserved there is some doubt as to its specific identity. It agrees with the Builiiigton specimens perfectly in the oriiaiiieiitation of the plates, but the second joint of the stem is de- cidedly elliptic, the radials somewhat more convex, producing slight angular depressions at the basi-radial and interradial sutures, the upper angles of the plates arc more inflected, and the facets apparcntl}- a little deeper. The ventral disk is depressed-homispherical, decidedly flattened at the top, the posterior side somewhat bulging, the orals comparatively small and very slightly convex, the covering pieces tuberculous. There are but three inter- ambulacral plates to each side, of which the middle one is extremely large, and erect except that the upper end curves abruptly inward ; those of the regular sides are subtrigoual in outline, but actually hexagonal ; the anal one wider, subcpiadraiigidar, and the top slightly excavated to form the anal opening, which points upward.

J I

I'l.ATYCHFMD.K.

608

Platycrinus glyptus Mvix. rint,' LXVII. Fiijs.4,0.

ISfll. TIm,i. i Drinriptions of Ni'W Ciiiioids, |), U'l,

bsl. W. !iml !Sr. (viir. ol' i". uni/ii/m); Ituvibimi, I'lirl II., |v H (I'MfCfil. Arml. Xnl. Sci I'liilii , |i. H:i).

As liiri^o lis the iiroceding siiecics, mid resenibling it in tlie roi'iii cf tl

10

u

ll\

nd

lie of

deli

iinentiitioii ; but the arms more miineroiis, 11 cute, mid compivrativL'ly sliorter. Dorsal cup goblet-flinped, height and wiilth about ei|ual, in very largo speeiiuens the height somewhat greater. Surface ma'-ked liy irregular, tindulated ridges or rows of obscure ii'^des, lollowing the margins of the plates, and increasing in number in the g, owing Ciinoid ; the radials traversed by two diagonal ridges from the facets to the lower angles of the plates. l?asi-railial and interbasal sutures canaliculate.

Basal cup comparatively deep, its height equal to one third the height of the calyx to the arm bases, the lower end rather abruptly truncated and slightly excavated ; interbasal sutures faintly visible. L'adials longer than wide ; the lower faces convex — those nieeting the interbasal sutures distinctly angular — anil .slightly beveled along the edges; the sloping upper faces forming a rather deep notch, which at the anal side is twice as w ide as at the other sides, and filled by a rather large, lozenge-shaped plate. Radial facets small, occupying .carcely a third of the width of the plates, and ex- tending but little downward. Costals subtrigonal, moderately large. Dis- tichals twice as wide as long, and not in contact laterally. 'I'he iiigher orders of brachials to the last axillary slightly constricted in the middle, and gradu- ally dccren'^ing in width but retaining the .same length, .«o that the ujiper ones ore as long as wide, and even longer in young specimens. Arms rather delicate and short for the si/e of the species; they are very numerous, there being from six to seven to each division of the ray, or twelve to fourteen to the ray, the bifurcations extending to fully one half the length of the anus, and above the palmars given ofT from the third plate. Structure of vi 'tral disl< and anus unknown. Column rapidly twisting; the two or three prox- imal joints circular, the others elliptic, increasing in length downward ; tlu^ long diameter of the joints fully twice the sliorter one.

Ilorkoii <i)ul LociiJitij. — Upper Burlington limestone; Burlington, Iowa, and Henderson Co , 111,

I!

cm

Tin: cuiNoinKA C'ami:iiaia or nouiii amkuica.

llnHtiiha. — 'I'liis .x|i( I'ii'.x is iipiii riiilly a ilodcuiidanl of 1'. sviil^itiis ; \\*

iu'in,s, liowcviT. are (Ii.'<Iiik'I uikpii^Ii lor spci'ilic Mi'iuiraliin

It

(IplU'DMl'lU'H

'PI

h'licliiiliiiriiiii^ in tliu bil'iiri'atioii of llic uniis, liiit llie liiiicliialrt fiuiii >\lii('1i till' iirms ari" ^ivi'ii olV to oik" liall' tlic li-nglli of tlii^ froc ra^ t» aiu not foriiu'il into rigiil tubes, hut retain liir eiiaiaeler ol' arm plates.

FlatycrinuB SalTordi llu.t..

J'/a/c I.XVII. Fhjx.J,.',.:.

]85«. Ham.: flcol. Hep. Invm, V..I. 1 , \'.n\ II., |. 'i:!.-!. I'ImIc is, IV n nml fl. l'■^l. \V. iiiLii M'. i Itivisi.pii, I'iul 11., |i. n (I'liinril. Aciul. Niil. Ni. I'liihi., |i. lib).

A lar),'o .«|ioi'ii'M. Ciilyx i.lilon^'. uiiusunllv larjje in iiroportion to tlie mnis, Dor.xal ciiii iini-sliMpciI. tlic liottoin lii(>a<llv tniiicateil. tlic sides i;railually sprcailin^ to tlie l)asi lailial suture, and almost ryliudrieal nlouj; tlie radials. OrnaUK ntalion of the plates as in tlie two preceding speeies. l)Ut irenerally somewliat coarser upon tlic ba.sals, while less distinct at the upper portions ol' the radials.

Basal cup larjje and scry deep, its lieijfht almost of|unl to three fourllis the lenLTlh of the radials; the holtoni Itroadly triuicated, almost Hat; the lower edjfc sharp, with an luululated outline. Ilailials sul)(|na(lrangular. anil in large specimens nearly once and a half as long as wide; the nnd- ilh' pniiions a liiile elevateil, csi)ecially toward the facets, the upper angles sligiilly inllectt'd. leaving a shallow angular depression at the suture line; the sides of the p'ntes parallel. Facets siu.dl, restricted to the cNtremo u])]H'r end of the plates, and occupying hut one third of their \\ idlli. Dis- tichals anil the plates of the higher orders to the uppermost axlUai'v nioder- •ately long, tin- (irst plate of each order narrower than the second, and all free from the costals up. Ai'uis short and of niodeiato -ize. given olT alternately; biscrial from the . second plate succeeding the a.xillaries ; there me from four to six arms in each suhilivision, or as nuiny as twelve to tlie ray.

A'entriil disk ilepressed honiispherical, tlio jilates more or less con\t'X. covered with numerous small piisiidi's. and each one crowned with two or three conspicuous nodes. Orals ver\- little larger tliiin the adjoining pieces; the amliiilacral plates on the pnmo piano with the iuleramlinlacrals. The latter are arranged: .1. 2. 1 ; the tuiddlc one of the first row large and licx- nngular, that of the anal side a little wider. Anus cxceiitric and directed

I

H

'.■»■■*

1

If

I'I.MV( IIINin.K.

606

I

^

lutiM'ivIIy. Colmim oli-'crvcil to ii loiijttli of -'> fin. witlioul Hliowiiijf cirri. Tlio joiiitM cimiigu riipiilly fVoin circular to ()Iii|iticiil, itml in \vi<Itii fmni 7 mm. t(i 17 mm. witliiii 41) mm. IVom tliu crown, iiml iVom I nun. lo .'( mm. in ji'n^'tli. Tlifir outer nmr^inM aro anifiiliir, nml tin' iniilillo portions com rod witli a tran.svt'rxo row of iil-ildincil nodcM.

//'■ri:"ii mill Lini/l/i/, — Upper Huriiiijjton lime.xtoiic and Keokuk gronj) ; Indian creek, Moiitjfomery <'o., Ind. ; Keokuk, Iowa, and thron^liont Ken- tncky, 'ri'iMi('s-<e(>, Illinois, and Missouri, at the .same ifcdloifical liori/ons,

7'i//)f in the (Worlhen) Illinois State collection. Springfield.

/u'liinr/.'n. — In a paper on "Transition forms in (hinoids" (Proceeil. Acad. Nat. Sci. I'hila., 187X, p. liM), we made this and the precedinj,' specie.'* varieties of P. xckIji/hs. They agree so closely in the form of the dorsal cup. and in the style of ornamentation, that it is impossihie to separate them unles.s tlio arms arc preserved, and even these do not diller es.sentially except ill numSer. We now rank them as full species. Imt Ijelieve that /'. uli/pliix and P. S'lJ/'onli are lineal descendants of /'. snilji/iis.

f^0v

Platycrinus scobina M iml w.

riitk LXVIir. F!ij^. I.',iijj.

ISOl. .Mi:kk anil AViiliTiii v; I'mri'id. \nA. .Niil. Sci. I'l,;:,, , p, rJ'J; ;ils(i (Icul. Iti'p. Illinois, V.i III., p. HW). rintc 111, V\i-. 9.

ISSl. \\. Mud Si'.; Ui'visiini, l';ii-t U., p. 7') (rnioml. .\niil. Niil. Sci. I'liila.. p. s!HO.

Syt. l'/ii{i/i-i-iiin.i i-lijlif — Itvi.i., IMil ; I'rcliiii. Dcscr. New Spec, din., p, \\ iilso lioslciii .liiiini. Niil.'llist., Vol. VII., p. 2S(1; li^'nircl is;^, X. y. Sli.te .\In». N;.l. Ili^l., Hull. 1, IMiit.' i.t, Viir. t, ami Mum. Am. Mns, Nat. lli,|., Vol. I,, I'art f., p. 2, I'liil,' ;!, Fi-. fl.

A small species. Dorsal cup basin-shaped, more than once and a half as wide as high, the radial-s sliglitly convex, especially helow the facets. gi\ing to the transver.se .section of the cup an ob.scnrely pentangular outline, and to the interradial sutures a shallow angular depression. Surface of cup orna- mented with muncrons small nodes or coarse granules, ratln'r sharply elevated, closely set, and irregularly arranged, which produce a I'asp-like appearance.

15a.sal.s clo.sely anchylosed, leaving no groove or mark ; they form a rounded basin, which rises to two fifths the height of the dorsal cup; the column facet .small, and almost on a level with the truncated lower face. Radials a little broader than long, widening somcwliat upwards, and present- ing a subquadrangular outline; the superior faces almost straight, tlieir outer ends l)eing but very slightly truncated. Radial facets small, occupying

^as

G'.M'i

I in: ( uixoiDK.v ( ami.iima oi' Ndiirii amkiik a.

I

M'iiiri'l^- dill' tliinl ilic wiilili III' till' |iliitcM, mill t'xti'iiiling Iml lillli' iiiwiinl. Coxtali* Hiilitriuiigiilir, tin- .xlnpiii;;- (i|)|ifi' liu'i'i concavi', tlic imgU' cIimiii i)iMticliiiIs iiiMi'ly an long um wiilr, iml in coiilart latonilly, cacli oiio giving olT twi> aniii. Aniii loiir lit tlio my. nitlitT di'licnli' from flu'ir origin, cnni- inKi'il ni I'liiiL'atc piri'i'H, wiiii'ii inii'riiicii IVoni tin' I'Dintli or iil'ili piti'i' and Iji'poMU' liiHi'i'iai ; ilnir joinln aro long, ami all niori' oi' less c'()n-<tricli'il ir'I'ohn till' uiiiMli'. Viiilnil ili'U nioilonitoly high, licniisplicrii- ; il.-* iilnliv iHini<r- on-'. TIk' intrraniliiilacrai [lii'ccs of tin- ri'gnlar hIiIi'm cnnsist nl' ihri'i- ami l\Mi plali's, >o far as olLservi'il. of which the iniiiilli' one of tho lir.xt row is largo; llu' anal wiilu lian (ivo in tho lirst langi', followoil liy nuim-ronM vory Hinall. consH'X pii'i-o.'*, forining a largo, will doliiioil jiiotuhoraiu'e, which oncliisos tho anus. Orals ami aiidmlacrid plates not visil)li' in the >pccinions.

Jf'iiT.'iii (iiiil hirii///i/, — liowor llurlington liiiicstiau'. IJiirlinglon, Iowa.

'J}//>e ill tho Mnsoinn of ('omparativo ZoiHogy,

Uniiarl.^. — IImU's /'. (/////s is a young Hpociiiion of /', unih'nin M. ami W., ami the fornior iimuk' should have priority if tlu' form had boon satisfactorily doscriliod ; liiit iinfiii'liin;iti'ly the short |iroliniinary iiolioo of it which Hall gave is in-iMllicionl for spocKic idonl ideation, and wo nuist in justice to Mi'eU

and Worthen epi their n,uno. Hall's more elalmrate description, «hiih

npiioared in l.'^'lil*, is misleading, for ho deserihes the Hpeeies as having only three arms to the ray. in Avhich it would he nniiiue among (dl Plntycrinidie. Hall's typo was imperfect, and the arms, (lecording to the llgiire, are iini- seriid thronghoul. as in all young specimens of /'/nt^criiins.

m

:''f"Vl

l» I ! I I

n:

Platycrinus parvinodiis iIai.i..

/'A,/, A.V /■///. ri;/s. (I,,, h.

]<r>l. II Ml ; llr^rr. Ni-w SpiT. of CrinniiN. p. 17.

|v^l. \\. :,M,1 Si , It.vlMMli, I'iiil It , p. 7:t (l'|-n,-,T,l. \c<.\. \:il Sci. I'hil.l.. |i 2ir)

A siiiidl speciei. Dorsal cuj) w ider than high, hroadly caliriilate, slightly (ilieiinic:d at the lower end. the sides ovenly eouNox, I'latos oxtrenuly thin, markeil hy irregular linos of sharp, very small nodes, pa.«sing from the radial facets to thi> lower !\ngles of tho plates, and from the rolumnar facet to the upper angles of the ha-al cup. with a few similar nodes irrognlaily scattered upon tho surface. The nudes in some spociinons are only vislhle with a magnillor. Rasi-radial and interradial suture- on a level with the general surface of tho plates.

m

■W

M.' —

rr.ATYciiiNin.T,.

(i'.tT

1

Dniuil I'lip Hoiiu'wiiiit iiliCDiiiciil, witli II r<li;.'lit ti'iiiii'atiiiii at llio lnuci iinl, lurroiiniluil \>y ii miiiuII cinMilur ri<lg(' ; lii-lglit ojumI in onu liull' (lio li'ii|;tli of tliu riulialM; hilciltiimil NUtiii'i'x oliliolcto. ilailiiiln Imi^tM' tliaii wido in llit' niliilt, 11 litlli' wIiIlt ill yoiiiij; H|ifi'iiii('nH ; llic Iciwcr Hk-o roninli'tl nt tin- iniii'^in ; llio niiii'M Mli},'litlv ciirNiiij; iiiwanl iumii' tin- li(|) ; tin' ii]i|)i'r I'aci' aliiio.>it Htrai^flil, .-Idiiiiig viT.V littlu ut the outtr finis ; tin- tiiil.T liicc nli. rii|itly ulovatcil liciii'iilli tlu< I'ari't, fDnniii^ a inoiiiiticiicc nr iid'Ic almnt t'qiial in r-'wM to the co^lal. Kaci'ls very kimmII. (lin'clcd ii|i\VMiii-. i» iii|i_\ iiij; rarely nioii' tliaii one loiii'lli the widlli of llic rinliiil", ami not ciiU'iin^ llio lioily of lilt' |iliit(', or only vory nliglilly. ('o,«ImI.' iiio>,MiIaiIy pciitaii^fii- liir. tilt- nlopin^ upper Hhm"* concave, the aiiglo Mliiiip. l)ij«ticlialM iwo. as loiij; as wiile, giviiij; olT two arms IVom each Hi<le. which icniain Miniplo. Ai'iiiH rather Hinall, coinposeil ol" inodenilely ion;;, iMiiieate pieces, which ((nulimliy interloi-k, and from tlie rndials np are constricted at iln" miildle ; tho sockets for the attachment of the piiinnles projcetinj.'. I'innnles not in contact, rii lier larj;e. Inlerraiiial plates erect, five so far as ohsi'rved ; the iniild'o Olio lai'j^e. siiiM|iiailraiij{iilar — that of the anal side widest — it is (landed at cacii side liy two small pieces, which toj;eiher rarely reach the liei>j;lit of the middh one, and liotli are in siitiiral contact with the disiiclnils. thus Iteiiig ^ lictly iiiiurlinichiiil in position. All oilier parts of the tci^mcn unknown

//"/■/'■. '■! mill h in tin 'I. — r<ow'cr niirlinjiton limestone, liiMlin:;toii. Iowa.

Tjiiif ill the Must ■'.'.'. of Coinparativo Z(«ilo^y. ' iiiinis. — This spe<'ies reseiiihles /'. fn'ohiim M. ami \\'.\ hut is readily distinj^iiished liy its much sum'"!' mid sharper nodes, which are .«parinj.'ly scattered upon the surface ; while those of that species are densely crowded. It :s also remarkahlo for the ahriipt elevation lieiieath the radial facet, whieli appears almost hh if constituting a part of the costals.

H

Flatycrinus geometricus w. ami Sr. (m>v. s|iic.).

Pfii/r LXVH. I-y. 10,, mil Pl.i/r I.XVIII. F,}/. S.

A small species soinewlint resemhiing /'. siu/iiiui, from which it differs in the greater height of tho dor.«al cup, in tho ornamentation, and in the pecu- liar form of the arm plates. Dorsal cup bell-shaped, about as high as wide, slightly spreading upwards. Surface of plates covered with kiiife-like. con-

si)icuous. undulated ridges or rows of sharp, confluent node,<, passing out

us

IH

'■?

I!

COS

TIIK (UINOIPKA CAMKUATA OK NORTH AMKUICA.

from the nrin Imses to the lower niigk's of tlie riuliiils, where lliey meet with oilier ridges racliiitinjj; from the column I'lieet, witli wliieli together tiiev form wi'H (lefmed rhonihs. Similiir riilges proceed horizontally from the radiiil facets to the r^iiles iif tile plates, constituting a ring around the upper end of the cup. K.ieh rlionih encloses about twelve prominent, densely arranged nodes, and other nodes (ill the triangular si)aces helween the rliomhs. Iiasi- radial and interradial suture lines not grooved, the interliasal ones otisolete.

Hasal cup broadly obconical, its height equal to iialf the length of the radials; the column facet narrow. IJadials slightly spreading, subqnadrangu- lar. three fourths as long as wide ; the lower face cfpial to the lateral ones ; the limbs at the sidi's of the facets a little sloping, supporting a very largo interradial plate ; the flieets extremely small, occupying less than one fourth the wiilth of the plates, and entering but slightly the upper margins. Cos- tals pi'ntangular. as long .MS wide, shai'ply angular at the toj) : the distichals as Icmg. but a little narrower. Arms four to six to the ray. (piite dilieate. and composed <if long, cnneate pieces which gradually interlock. The brachials, tioni the radials up, jirovided wilh well defined sharp projections at bdlb the up[ier and lower eiiils; the middle porlions deeply constricted, proiliicing a .'omewhat /ig/.'ig !ippearance ; the lines of union rather gaping. Pinnules moderately strong, and not in contact. The ventr.'d disk is eovereil by the anus ^n t\n' two specimens exaniiiu'cl. wilh the exception of the interradials of the lirst row. the middle one of whicdi is proportionally large and covered wilh nodes similar to those upon the radials. the two at the sides being nar- row and without oi nai'ienlalion. Proximal stem joints circular, wilh small nodes surrounding ibi'ir juargins.

Ilnri-.iiii <niil /.' iiillfi/. — I'|i|)er Burlington limestone : nurlington, Iowa.

'J';/jn^ in the Museum of (.'omparalive ZoJilogy.

Platycrinus nodo-striatus w. iin.l .'^r. dinv. spop ).

]'/<!/>■ LXVr. /•%/>•• ->'• ''.■ P/"'-- /-A'.V. /•'/>■■ 'l-f"- ''. '••

ftf medium size. Calyx globular, about as wide as high, rounded at both eii'ls. Widili of dor-^al cni) once and a half to twice its length, the entire surl'ace of ibe jilales densely covered wilh more or less conlliu'iit uoiies. arrangeil in concentric lines around their margins, and traverseil by two well delined ridges or rows of nodes p.'issing out from the facets to the lower angles of the plates. The iiocles sui'ionnding the column facet more pronii-

u\

i

m

!-^tl1^

i

*

IM-ATYCRINID.E.

C99

neiit and larger, forming a sort of rim around tlic stem. Siitiirc lines slightly grooved, except the inteibasal ones, wliieh are invi>il)le.

Basal cup moderately deep, its height equal to almost one half the length of the radials; the bottom slightly truncated, and having a circular depres- sion wide enough for the reception of the proximal stem joint. Itadials a little wider than long, slightly spreading upwards, the outer ends of the upper face distinctly truncated ; the facet semicirculnr, deep hut rather narrow, directed ohlitpiely upwards, slightly notched at the top. Costals small, sometimes not occupying the fidl width of the facet. Disticlials twice as wiile as long, free above the costals. I'almars as long as, hut nanower than, the ilistichals. Arms six to eight to the ray. rather long, the three or four proxinud plaies above the axillary cuneate and uui^erial. those beyond gradually passing into biserial. Ventral disk one third slau'ter than the dorsal cup, sub-pyramidal, the plates convex. Posterior oral larger anil more prominent than the others, the latter twice as Inrge as the adjoin- ing covering pieces. Andndacra almost on a levid with the general surface, dividing upon the disk. Interainbulacral plates 3 iind '_'. those of the (iist row in ])art interbrachial and almost tint ; the middle one hexngonal and longer than wide; the two at the sides scarcely bending outward. The middle plate of the anal side projecting and fornnng with the plaies above, which are quite small and very numerous, a low riilge following the median line. Anus low down, directed almost hori/ontally. Cnluinn facet circular ; the stem joints eUi|itic and twisted, those close io the root nearly three times as widi! as the proximal ones.

JItirl~.ijii (iiiil Locnlit;/. — Upper Burlington limestone ; Burlington, Iowa.

7'//yw in the collection of Wachsmuth and Springer.

Juiiitcrhs. — .Meek and Worthen have referred this form to /'. tmiii- hnirliiiihix, as their figure 4f) on Plate .1, \'ol. V. of the Illinois lieport eviilently represents this species, the ornamentation not being correctly given in the figure. It differs from that species in the more elongate form of the dorsal cup, the much deeper bas(>. and the surface markings. Specimens of this tyjie exhibit miu'li variation in number of arms, nine arms to the ray being sometimes found. Figs, 'ut, h, on Plate I.W'l., repre- sent a variety from the Lower Burlington, which we cannot distinguish from this species.

\l\

(

%

'^

■fJ

700

THE CKIXOIDKA CAMERATA OF NOBTH AMERICA.

Platycrinus peouliaris w. an.l Si-. (nov. siiec). J'late LXVIII. Fl,js. 7a, h.

Of niediiim »\7.c. Calyx one third liiglitM- tliaii wide ; the dorsal cup about as wide as high, obcouical at the baso, oyliudrical along tho nulials ; the platos rather thin. The ornamentation of tiie plates cannot be accu- rately ascertained in the speciinens, but tlie surface shows traces of obscure ridges passing down diagonally from the radial facets to the lower angle." of the radials. and from the colmun up to the angles of the basal cu]). which suggests that the surface was marked in a similar manner as in P. scidjitiw, but perhaps less distinctly. The sutures slightly grooved.

Basal cup basin-shaped, its height eipial to one-half the length of tho radials. gradually expanding upwards, and slightly beveled aroinid the upper margins; tlie eoUuun facet small, souu'what projecting, aiul the interbasal suture liiu's distinct, lladials sulxiuadraugular, nearly as wide as long, the median line sometimes a little elevated, the lower faces very slightly convex ; the lateral faces almost piiralld. the sloping upper faces wide and forming luoad interradial uotehes. of wliich that at the anal side is deeper than tho others. Facets extremely small, not occupying more than one foiu'th the wiilth of the plates, and often considerably less. Costals small, as long as « ide. occupying the entir<' i'acet. Distiehals narrow, ahuost as long as wide, all in sutinal contact with adjoining interradial platos. and as such constitut- ing a part of the calyx, although having the form of free arm plates. Ven- tral disk hemisphiTic. slightly l)ulging at the anal side, studded with nmnerou.s sm:ill. nodose pieces, of very nearly equal size. The or.ils unusually suuiU ; the ambidacral pieces on a level with the other disk plates, and of the same size ; they are very regularly arranged, and branch upon the disk. The interradial plates consist of three rows of three each ; those of the first row .are perfectly flat, and interbrachial in position, the others being noilose and interambulacral ; the middle ])lalc of tho first row very largo, oblong and hept.igoual. the two .at the sides as long, but very nuich narrower. Anus exceutric, at the top of a small protuberance. Number of arms unknown.

If'irir.mi Kid l.'u-uJ'dj. — Lower Burlington linu'stone ; Lake Valley, New Mexico.

Tijpr. in the collection of Waehsmutli and Springer.

•

I

I , I

PLATYCRIMD^E.

701

liemarls. — l\c>i{!m]>Vmi^ P. jwrrinodiiK in its gciiernl structure, but diiTer- wg in the details. It is readily distinguished by its more elongate form, and having the lower brachials to the top of the distiehals always preserved in tlie specimens by reason of their sutural iniion with the interradial plates.

onxiaiiANUL US an o i v.

Basals and radials forming a cup with moderately .spreading sides, the radial facets deep and wide ; arms short and vu-y heavy throughout j the plates covered with coarse granules or irregular nodes.

Platycrinus ornigranulus McChksxkv. Plate LXVI. Fhj. S, an,/ I'Mc LXVIII. Flys. Mh. h. c, lJ,i, h, nwl 12n, h.

ISOO. McCiiKSNKV ; Dcscr. New I'lilicoz. I'ciss., p. 5; niulTriins, Cliic;i!,"i Acail. of Sci., p. 3, I'latc 5,

ISSl. AV. luul Si'.; Ki'visi(jii, Tart. II., p. 7;i (rnifcnl Aciid. Nut. S<-i. I'liila., p. 217).

Svii. l'l,i/'/,;-iii„.i m'/ii/ii-iim llu.l,, 185:! (iiul (lolclfuss, ISli:;); Ccol. llcp. 1uh-:i, Vul. I., I'lirl If., p. 5U.

Caly.x of medium size, cup-shaped, moderately spreading ; the ijase but .'ilightly convex, the lower part truncated, ami the median portions abruptly depre.s.sed for the reception of the column. Surface of plates entirely and closely covered 1)3- small granules of irregular si/e and form, those nearest the margins .smaller and more closely in ranged, those surrounding the col- mnn facet continent and more or less ill-defined. Similar granides, but smaller, cover the arms, each plate generally having two rows, transversely arranged.

Basals forming a very shallow saucer, of which the boltom is flattened and only the outer margin is visilile in n side view ; the columnar attach- ment circular, and marked by distinct radiating striie ; interba.sd sutures altogether ob.^olete ; basi-radial and interradial sntin-es .slightly grooved. Railials about ns wide as loivr. the sides nearly stiaight. the width of the lower face nearly equal to the length of the lateral ones, the upper faces at the sides of the facets deeply nc.tclicd. Facets large, occupying nearly one half of the width, and fully two fifths the length of the plates; slightly thieUened around the edges; concave; directed outward; the margin of the face crenulated. Costals triangular, .short but wide, covering the whole facet; their sloping upper faces concave. Distiehals two. the npper one larger than the lower, the latter y-ivinsj ofT an arm to the outer side, and

f

4

II

1:

702

TIIK CiUNOIDK.V CAMKUATA OK NOHTII AMKHK'A.

two j)uliiiar> witli two iiiiiis to tlio inner. Arms cyliiulriciil, verv stout for tlio size of tlie species, and not tapering except at the tips ; tiieir plates sliort. Pinnules strong and closely set, the joints three to four times as long as wide. Structure of the ventral disk unknown.

Ifirk'in dill Lxnilili/. — Lower Burlington limestone, Burlington, Iowa.

T1//1C destroyed in the great Chicago lire.

liinmrh. — 'I'iic ornamentation of this species is vciy varialile, as shown by the illustrations. In some specimens the entire surface of the plates is covered with small hut distinct nodules, in others the nodules are confluent and the surface appears to be coarsely granulated ; still others have irregu- lar larger nodes at the median ])ortion of the radials. The basul disk is also Hatter in some specimens than in others.

• f

Platycrinus WorthoDi II vu,. I'liitr LXVILFItj.O.

lv-.<«. IIh.l: fi.v.l. lirp I..«:,. VmI, T., I';uI II.. |. WM). VUw S. Fi<:. 1.

bbl. W. and Si'. ; H^^i^mu, I'^irl II.. |i. ~,i\ (I'looivil. Acail. .\at. Nm. I'liiln.. p. a.VO.

Of medium size. The species is of the type of /*. ^xvvrsyx ;•, and has a similar orn.-imentation ; Ijut the dorsal cup is more elongate, the nodes upon the plates are less regular, and angular instead of muuded ; also the basal disk is proportionally larger, the radials longer and more erect, and each half of the rays has four to five arms instead of three. Dorsal cup oup-shajied. angular along the interradial sutures, and truncate at the base ; its whole siu-face deu-^ely covered by prominent granules or subspiniform nodes.

Basal disk concave; sharply pentagonal; the extreme outer margins on a level with the lower eilges of the radials ; the proximal stem j(>ints circidai'. Hadials as long as wide at the upper end, subiju.idrangular. the lower faces truncated, the sides very little expanding upwaiils. F.'icets wide an<l deep, surrounded by a projecting rim. the u))p('r margin broadly excavated. Basi- radial and interr.ulial sutures slightly grooved, the intcrbasal sutures obso- lete. Costals small, trigonal, wider than long. Distichals short, nuire than twice as wiile as long, and the first, as well as the second, resting within the facets, their inner faces suturally uniteil. as also those of the palmars. The plates of the two succeeding oiders of bracliials ore but slightly smaller tliau the distichals, ami the second plate of each order, as in the case of the dis« tichals, is wider than the first. Arms eight to ten to the ray, rather stout,

PLATYCRrxin.T:.

703

very graiUmlly tapering iipwunl, and covered tliroiigliout tlieir full length witli granules, similar to those upon the dorsal cup, but smaller. Structure of the ventral disk unknown.

Jfurixiiii and Lick/I/i/. — Lower Burlington limestone, Burlington, Iowa.

'J]/jic in the (Worthcn) Illinois State collection.

IIEMISPHEIUCUS GIlO UP.

Calyx to the arm bases more or less cup-shaped ; the sides slightly spreading; the plates covered with distinct nodes. Aiuis of moderate size.

Platycrinus hemisphericus ^r. ami w.

riate LX VI. Fhjs. ]„, h, c, d.

ISfiS. Mv.yy. nnd Wouthkx ; I'r.irccd. Ac.-ul. Xiil. Sci. l'liil;i., p. lOi ; iilso ISCO, Gi'ol. Rep. Illinois, Vol.

III., p. .'ill, I'l.itc JO, Kills, i„, I,. ISM. W.aiulSp.i Itcvi.siim, I'ait 11, p. 7i (I'roricd. Acail, Xal. Sci. I'liilii., p. ■ill',).

Caly.\ subgl()1)oso, rather largo in [)roportion to the arms. Dorsal cup liowl-.-iJiaped, twice as wide as high, the bottom excavated for the reception of the column. Basi-radial and interradial sutures slightly depressed but not grooved. Surface of plates covered with rounded, rather large and prominent nodes. There are generally five rows of such nodes at the base, three or four to each row, which pass out from the column ficot to the upper angles of the plate, forming triangles, which are filled by adilitional nodes. From the radial facets two other rows of nodes pro- ceed to the lower angles of the radials, which are triangularly arranged like those upon the base, aial the.-<e al.M) enclose a variable numb(>r of similar nodes. The sides of the plates are covered with smaller nodes of irregular arrangement,

Ba.sds forming a shallow basin with a .flight depression at the lower end ; the interbasal sutures indeterminable, Radials subfiuadrangular, wider than Icmg, moderately expanding in width upwards ; the upper faces at the sides of the facets very slightly sloping, except at the anal side where they form a broiid and deep notcli. Facets horse.<hoe .>*haped. occupying one third the width and height of the plates ; directed obli(iuely upward ; the face con- cave ; the upper end deeply notched, Costals very small, trigonal. Dis- tichals free above the first, which is very short ; the second a little longer. Pahuars, and post-palmars when present, as long as. or longer than, the

i

J

704

TIIK CKINOIDK.V CAMKKATA OK NOUTII AMKIJKA.

ili.Hticlmls. Arms from fix to oiylit to tlie my, given ofl" alteriiatcl}' IVcmi opposite sides; coinpariitivel^' thin, unci gnuluiilly tapering to ii slinrp point. They are even in the most mliilt specimens uniserial at the proximal end. being com|)Osecl of cunente pieces to tlio fifth or sixth plate above the bifur- cation. Tiie interlocking of the plates evidently took place in this species at a late period in tiie growtii of the individual, lor in a specimen in which the crown measures 22 mm., they are still uniserial to tlu' very tips, 'i'he joints are ratiier long, and tiieir surface is covered by small granules, so minute that they ai' ■visible only with the help of a magnifier. The edges of ap- posed faces, from the costals up, are distinctly serrated, and the median por- tions of the lower brachials arc provided with a small transverse ridge. Pinnules closely arranged in the adult, separated in young specimens ; the joints very long.

N'entral disk hemispherical, slightly bulging at the sides, the plates tuber- culous, large, and nearly of equal size. In some s])ecimens the orals are some- what larger, and the posterior one sometimes bears two or tiirei' nodes instead of one. The covering plates are arranged in rows, and pass out from the orals. lnterami)ulacral pieces apparently lour. Tiic amis is located low down at the side, and is very rarely seen, being most generally covered by a Ctijiiilu.

Stem moderately large, circidar at the extreme upper end. then tiu-ning to elliptical. The joints gradually increase in length, until tiiey are at the lower end of the stem three times as long as at the ujiper. The outer mar- gin of the upper ones is surrounded by a row of small nodes placed at ccjiial distances, but on approaching the lateral a])penilages there arc but two. which are larger and placed at the long diameter of the joints. Length of the stem not I'xceeding 25 cm., but generally shortey, terminating in a sharp point. Lateral cirri short and circular.

Horizon mill Luculi/i/. — Keokuk group. Found in large quantities and excellent preservation at Crawfordsville, Ind. ; rare at Keokuk, Iowa.

l'i/j>e in the Illinois State collection, Springfield.

H^#3ftr

!'/-.^^

m

■^\*

I,

I'LATYCRINID.K.

706

FlatjrcrinuB vemxoosus Whitk. Plate lXVI. FIijs. Ju, b, ami Pkk LXVIII. Fijx. la, h, c, d.

ISGi. WiiiTK ; llost.jii Juurii, Not. Hist., Vol. VII., p. flOi.

Of mc'Jium size. Calyx below the arms deeply enp-.ihnpcd, n1)oiit na wide n.s high ; the Hiden almost straight, and the suture lines not grooved. Surface of the cup marked by somewhat scattered, very prominent, wiut- liko nodes, elevated abruptly. They are irregularly distributed, except upon the basals, where a row of ten large elongate nodes surround the column facet, their sharper ends jjointing to the coUnim, the thicker and wider ends directed outward ; tliese are enclosed by an irregular row of somewhat smaller, rounded noilcs. Surface of the arms not ornamented.

Ua.sal cup large, saucer-shaped, pentangular in ouiline. the angles point- ing upward ; Hat at the bottom, the colmun facet circular, moderately large and but slightly depre.s.sed ; the interbasal suture lines indeterminable. Ra- dials sometimes a little longer than wide, the lateral faces straight and nearly parallel, the lower faces convex, the upper faces at the sides of the facet short and but slightly sloping. Radial facets less than half the wiillh ot the plate.s, and occupying but a small portion of their length. Costals small, trigonal, Distichals of the same ray in contact laterally ; the first very small, the second ."omewhat larger. Palmars larger than the distichals. Arms four to si.v to the ray; smooth, rather long, moderately heavy at. the proximal end, but tapering slightly upward. They are eomjiosed of rather long pieces, which become biserial above the third plate. Pinnules long. Structure of the ventral disk and column unknown.

ILirh.im and Ijinilif//. — Lower Burlington limestone, Burlington, Iowa.

TyjK' in the Museum of Comparative Zoology.

^i

80

I

N,'

TOO

TIIK CUIXOIDKAC'AMKRATA OK XOIMII AMKIMCA.

Flatyorinua pooilliformis \l\u..

I'luk I.XVJII. Fhih. J,l, h.

|V,S. II1I.I,; (ii'ul. 1(,|,. 1h«;i, Vul, I , I'.ill |l„ |,. .-,J<. I'liltl' S, Fit's. i„, h.

b>l. \\ ;ui,l Si' ; Urii.siuii, I'liil II., ji. 71 (I'r.c.ril, .\ciul. Niil. S'i, I'iiihi., p. SIS)

A little sliortiT tliiiii the prt'cedin;^ .>*i)c('ic'f(. Calyx to the top of the liiiliiils (•iip-sliiipi'd. wilier than hij(h ; the heij;lit of the hasaln eijiial to nearly oiii- thiril the length of the enp ; the wiile.s very .-^lightly expanding to Iho middle, the npper ends at right aiigle.s to the hase ol' the enp ; the .siitnro lines not grooved. Surface of plates marked hy rather chort, rounded nudes, wliieh upon the liasals are arranged in douMe or triple rows, a row of three extending IVoni tiie eolmnn facet to the uj)i)er angles. The radials geiuraliy have a row of four or hve nodes running from the radial facet to the lower angles of the plates, which eiiclo.so four or five others, and there are three or lour at eatdi side.

15a>id.-< forming a Hat, pentagonal cup; the colunni facet small and handy imiires^ed ; tiie inteihasal suture lines indistinguisliahle. Ihidials ii little widi'i' than long, (|UMdrangnlar, the upiier face constituting an almost straight line ; facets snuill, directed ol)li(|uely npwaril. restricted to the upper ends of the plates, and occupying l)ut one third tlieir \\idth. Arms apparently live to the ray, and ornamented with small nodes. Jl''i'i~"H and /."Cdli/i/. — Lower Burlington limestone, Burlington, Iowa.

7}//ii in the (Worthen) Illinois State collection. Springfield.

Hi iiKiika. — Dilfering from P. n rri'i'usns in the shorter calyx, in having less prominent, and dill'erently arranged nodes, and in the ornamentation of the arms.

Platycrinus Yandelli o. nnd sn. (tyjiicii Umn).

Phiic LXVI. Firjx. (la, h, r; and Plutc LXVITL Flijs. .'„,. h. c.

1S5J. 'Ihks .■mil Sill MAHii; L'. S. CnH. Hep. Wise, Iciwn mid Minn., p. IJ*;', Plate ."1./, I'V.'s. fui, b, e. 1-sl. \\. !„ul Si'. ; K.'visinii I'lilit'orr., I'lirt II., p. 7i"i (I'nici'cil. .\c.'iil. Nut. Sci. Pliihi , p. iM).

Of medium size. Dorsal cup low cnp-shapcd. ohscnrely pontan"ular from a dorsal view, the interradial suture lines forming the angles; the sides nearly straight, slightly expanding. The radial facets almost in the .same plane with the surface of the plates, and nnnsnally large, occuiiying fully half the length of the plates and two thirds their width. Surface of hasals

U

ri.AIVCUIXID.K.

707

><%

mill niiliiilf' covciim) wiili coiiipiirativt'ly few, irn'^rnliirlv cli^iiiliiitiMl, riitln'r largo mill |)riiiiiiii(Mil iioduH, which «oinotiinc.>< iilnioxt liikt- liii- cliiiiin'tcr "f siiiiu's. Till! costuls. ilisticlmls. mid lower piilniiirs liiivo from two to thrco iioik'M, which lU'i! soniewlmt siiiiiUlt tliiin tlioso of tlu' calvx, mul triiiisvorsrly iirr!tnj;('(l, while the biseriiil arm jilatcs have hut one, iilnceil near (he inner (Mill, forming together with luljoiiiing ones two rows along the hack of tlio arm.

IJasals t'orming n pentiigon, willi a eirciilar. rather ileep eoiicavity, wide enough to admit the two upper stem joints. Inleihas.il sulures fie(|uently iiivisihle; the hasi-radial and interradinl suture liiie-i slightlv grooved. Hadi- als hexangnlar. Mio upper oikIh of the plates one third wider than the lower. Facets w^'v large, facing outward, shallow, transversely idliptical ; the upper end slightly excavated for the aiuhulaeral jtassage. Coslals lai'ge. triangular, occupying the full width of the facet. There are normally live arms to tiie ray (exceptionally four or si.x), one division with three arms, the other with two, the former having two distichals lo the inner side ; anus of moderate size, their lower ends curving slightly downward ; the arm joints rather long. N'entral disk from a third to a half higher than the dorsal cup; the outer ends of the amhulacra slightly protruding; the [ilatcs highly elevated, their summits crowned by two or three sharp tiiherdos. Orals large ; the posterior one pushed to the anterior far enough to he in a straight line with tiie two postero-latcral ones. Amhulacral plates large, arranged tjuite regularly in two rows. Intcramhulacral plates from four to five, except at the anal side where the iniddle one of the first I'ow is much larger than the corresponding plate of the other sides, and followed hy a great nuniher of small tumid pieces, which form a large, conspicuous, suhceiilral protuherance containing the anus. The two plates at the sides are twice as long as wide, and longer than the niiddie one. Column distinctly twisted; the joints slightly angular around the margin ; their long diameter diual to twice the shorter one.

Ildrh.nn find J,iiiii/l/i/. — Lower Burlington limestone, llurlington, Iowa.

JuniKi'ls. — The dorsal cup of this species ia less discoid than it appears in specimens with the arms preserved. The arm facets enter deeply upon the plates, and the lower jiaits of the arms are directed hori/onlally, often with a downward tendencv.

«,l

708 THE CUIXOIDEA CAMEUATA OF XUIUII AMKKlCA.

PlatycrinuB Tandolli, vai. poraapor sm m.

riui, LXViJi. Fi^/x. 4<i, i>.

l>illj. P./iirin/hr — 8mil\H|ii (',ir:il I'liliiiij:, Khm. nf Nnitli Arncr , |i. ;t'>9.

18>1. J', i^iiw/i^r — W . nwA Sv. ; H, \i<j.iii, I'lirl II , |i. ;:i (I'l i il. Aiml. Nut Sim I'liilii., |i, 817).

S\ii. /'. HuilohraekmlH' llur,, ImII >w,\ bro); Diwr New t<|nc'. cil (Vin.. y. 17.

In tliu foriii uf the ilorHul ciii), tliu iiropoi'tiuiLs uf its pIntcH, niiil the >i/u of (lie ai'iiiH, cIoMoIv ri'xi'iiiiiliii}; /*. ViiikIiIH. Init tlio ikhIoh covoriiij? the niir- fai'o imicli iiioro nunicrous ; llicy iire pliictMl close toj^t'tlior willimit bciiij; coiitlianl. arc very piomiiii'iit, and covor tlie (lorsul Mmlaci' of lint anns. Tliosc upon the hnicliiiils to the Inst axiilaiy. altlioiij^h Hnialler, are e(|iiMlly well (lelined. and are ai'riinjied iriiiisversely in fwn rows of from lour to live nodes to eaeh row, those upon the hiserial arm plates in oidy one row. The latter are more or less eonfluent, and form an nndulated riilj;e at the iip|ier od^e ol" the plates, wliieli ujves to the transverse ontures a \va\ inj? outline. This variety j^enendly has si.\ arms to the ray. whiidi are sli^ditly llatlened on the hack and ohseiirely jrrooved aloiii; the meilinn line. The stem twisl.s rapidly, and is eoitiposed at its |)ro\inial end of short elliptic Joints.

lliiri'iiii iiiitl I.iiotlil;/. — [iower Hiu'linu'ton limestone, Darlington, iowu.

Tijpi: in the Museum of Comparative Zoology.

Flatyorinus spinifer w. wwA ^w (nov. bjicp.). I'hii,' rxVI. /■'!//. 7.

Closely rcsendding P. Vninlilli, hut somewhat larger. Porsal cu]i saucr- shapeil. the hasaN proportionally large, the radials distinelly enrxing. tiieir faootH projecting outward. I'lates thin. eovere(l with huge, rather sharp nodes, placed in concentric lines parallel to their margins; there heiug gen- erally three sueli lines upon the hasals. and two or three upon the radials, the latter arranged .so as to form a diagonal line from the facet to each lower angle of the plate.s. Similar nodes, hut somewhat smaller, cover the .•iruis. every ]ilate ahove the costals having three nodes — the costal^ four to five — tran.svcrsely arranged, and occupying the meclian line of the plates; sometimes, however, in the up|)er part of the arms, the nodes hecomo confluent and form undulated ridges.

Ba.sals large, .slightly convex e.xoept the nii<ldle part, which is abruptly

;i

VLATVnilXID.K.

TOO

(IcpruHscd for llio roocplion of tho coliniiii. Tlie iiitoibamil mituro liiU'.M iiiilult>riniiiiil)lu ; tliu liiini riidiul ami iiiti>rrailiiil KtituruM on ti livcl wiili tho |iliit<'.'<. Uiuliiili nipiilly ><i>rL'Uilin^, t(iiisi(l»'nil)ly wulur tliiiii Imi^ ; tin- K'li^tli of the liiteriil liiec^' Icsm timii lliu wiillli nf tlie Iowit out- ; tlu- liiiil).-* inciiivinj?, Hlopiiig oulwanl iiinl fortninj? witio inn) dfcp notihcH hctwcfii tlio pliiti'M; tliuir upper cihIm Hliurply iinjfultir and liighcr tlian tlio upper part of tlic facet. FiicelM larj;e, (U'eiipving half the width and fully one third tho len^lh of the plates; deeply .uid hroadly excavated at the np|)er end. Coslal.t liroaiUy liianj,'nlar, rapidly xlopinj; at the miildlo, their lateral e.xlen- wiiin* knife like. Fir:<t dixtiehal placed oliliipiely, the ^'ec()nd wider and hi;j;her than the (irsf, and overlapping' it laterally ,■«) as to tinich the costals. I'alinarn of the Maine proportion.-* a.s the di^ticlials. Aiin.n j:;enerally livo to the ray, exceptionally six; cylindrical, very iieavy anil proportionally hhort. The ventral disk of this species was hi^h. as indicated f-oni fraginei\(ary ])arts preserved in one of the specimens. 'I'he inlirainlnilacral regions appar- ently consisted of live plates, of which the niiildle one of the (irst row is very Inye. and nearly twice as wiile as hi;;h, the two at tho sides ns lonj; Init narrower; the former havini,' a eeiitnil spine. Colmnn distinctly elliptic, tho edges of tho joints stndded with ninneioiis smidi nc des,

J/iir!:i)ii mill l.iiiiilil//. — l.cwer Hmlington limestone; Hnrlington, lown.

Tiji'ii in tho collection of \Vacli>mnth and Springer.

Uiiiiiiik.'*. — We were at first inclined (o regard this fi.rm a.s a variety of /'. YiiiKhll! ; Imt the diiTerences in the si/o of the hasal disk and tho propor- tions of the arms, as well as in tho form of tho doisal cup. are so rcmarkahlo that we ccMicliidi'd eventiinlly to treat it as a fnll s])oeies. It agrees in tho form of the dorsal cup with the Discoidons gronp. hnt in tlie ornamentation and arm strnctnro it is nearer /'. VninhUi, P. r<rrnriJ!<ii.i, and 1'. heitiixjiJariciw, and it donhtless represents a transition form.

t

FlatycrinuB spinifer var. elongatus w. ami Sr. (nov. var.). Plate LXVII. rhj. 7.

Verv closely allieil to P spi!)l/rr ; the dorsal cnp deeper, hnt very little expanding, the hiisnl di.-k larger and almost Hat. The radials rest npon the inner edges of the hnsals. and are as long as wide; their facets mnch wider than high, directed ohlirinel^- upwards ; they extend to less than one third the length of the plates, hnt oecnpy half their width. Cost.ils trigonal,

Till

rilK ( lllNOIItKA CAMKIIAIV Dl' NOIITM AMIIIK A.

not taking u\i ilic lull vviiltli uf ih • fuci't* Arim Hm- Io fix. iiniiiiKfi! i\» in /'. MjHiiiJ'rr, and i-ovort'il by Hiniiiur u-x' • aUd ilii- plalt'i*"! tlio ilDinal I'lip. Vciiliai (lisi< high; the t'liils luigo, ' ' a ^liirhlv fic\ato<l n'ntral noilc, wliii'h at tiiL« top (livi(K'.'< into two or i' • .-in. p prociwcs. The inlnainliii- liicnil |iialt«« Mat ami t'lfi'l ; the niiihlli' one of liio l.-.M row hIuh'IiI^' hosan- giihir. ami ln-aring u nniali (•cuiiai liilu'icli'.

Jliirizmi iiiiil f.iiiiif!/'/. — Siiiiii' M^ laf<t,

J'l/jitu in the coili'ciion of Wai'hi^imilh and Springer.

Ji'iiiiiiiin. — MoMt of tho npiH'imi'nn of ihiH Hpei-ii'M agri'c in (lie form of tlic (ior:^Ml cup with the Dict'oiilons grinip. Iml in the ornanifnialion and nrni Mtnifturi' rcfiiniilL' /'. ri rrnruKiis, P. /iniiiyi/nrii us, nui\ J'. YiimhUi. 'I'hi'rc art' oilier Hpeeinienx, however, in all eKMenlinl points agreeing with Ihe former, in wliieh the cup i» deep and oblong, for which tlio name P. sjilni/er, var. i/iiiiijiiliis is propoxed.

HKCAUs annrn.

Cnl.vx cup-shaped, the piaies indistinctly ornamented ; the arms curving outward, and very heavy throughout.

U I

Platycrinus regalia Hm.i..

J'/atr /.XXU. h'i'js. I. J.

1»|'>1 lt\T.i.: IVwr. nf Ni'W S|ii-r. nf (■^lll..ill^, p, |il; lii.'Mii(l {^r!. Ni'vv Ynik Stall' \\w>. nf Nut. llisl., I'Uh' i.l. Kiu'. "1.

l-M, \V..,n,ISri U,'M,i I'ail 11, p. TKl'runT.I ,\™l Niil. Nr I'lula., |.. •it'*).

Smi. /'. (lirriii Mkkk mill WiiKriiiN ; rnicTfil. Ai-iiil. Niil. Sci. I'lilla., \<. IJU.

A rather largo spei'ies. ('alyj; liroinlly eup->hiip('d. and hut slightly spreading; liase large, rounded lielow ; radial facets greatly projecting. Arms at lirst direeleil outward, in some specimens .>^preadiiig hori/.ontally to almost one thiril their length, the upjjcr ends curving iinvanl until the tips rest upon the ventral disk. Surface of the plates marked hy two or three undulated ridges or rows of indistinct nodes, parallel to the upper margins of the plate.s, and similar ridge.s, hut narrower, surround the edges, giving to the sides of the plates a sonu-what heveleil appearance.

Hasal cup unusually large, pentagtnial, its inner edges resting against the lower faces of the radinls, sometimes overlapping them ; the interha.snl .^nlnres distinctly grooved. Radials generally a little longer than wiile. slightly expanding, the lower faces convex, the upper faces at the sides of the facets

I

•#«

t

It

if

I'l.ATVCHIXID.K.

711

iliNtini'ly Hlopin^, ami iIminc towiinl tliu iiiml mJiIc ciiimiiloriihly wiiliMl, giving to (lie I'lici'tH 111' llio piistLTioi' rii^s nil i-xci'iitrii! iiifition. Kiici'ti oo'ciiiniiig uiui lliini tliL< wiillli iif till- |iliitt'<«, iil)i'ii|)ll_)' |iM)jtM'liii^, tlif fac'i"4 .tli^^'lilly cuii- vex, till! iiiiicr iniirgiii ci'i'iiuliitt'il, iiml the iiiciliuii |ii)rliiiiis inDviilcil wiih an ulixenio triiiii«vi>i':<o I'iil^i*. CuhIiiIn iiuiduratL'ly largt>, |H'iitiingiiltki', roiiinli'il on llio liiick, tliu ii|i|ioi' aiiglt> olitiiHt', tilt! iippfr Hlopiii^ facoM coiiravi', hoiiiu* liiiii"* ri|iri'siMiti'tl l»y two plaliw. Diftlii-liaU two, a^* l:ir;;<' a" tlit' costuls, ami tlio iippi'i' pJMli' iai^'t'i' lliiiii till' lowur. Tiii'V j{i\o olV an arm iVom llic miliT nIiIo, mill two palmare from tin- .unci', uliirli latter Nupport an arm at llic Olio Hiilo, mill two poxt-pulmaiH with two aiiiiM at tlio otlii'r; l'ri'<|ni'iitly, liow- cviT. tlicri' i.t no I'lirtliiT division almvi! the pahnai'M. The numln'i' of arms VMrit's rroiii n'w to nine to the ray, anil often in the HMine specimen; the iirniM are very Ntiint, ami taper hut sli^^htiy ; their [liate-* up to tiie iant birnrnitiiiii nrc constricfeil in the miiMlo, ami the riil^es altovc mid helow in well pro- nerved .ipeeimeii-* are oh-'curely nodo-'e, lhoi<> of the liiserial upper part hli^'iiily eonvex. Siriii'tnre of liiu ventral ilisl< mil\nown.

Cidninii unidiially iiiorenHin;; in widtli to alioiii "li mm. from the i nd, whenee it t.ipers rapidly to ii point. Its entire ieiit:lli, ai pre-.eiited in ii moderately lar^e specimen I I'liite liXXII., Fi;,'. 1 1, is aliont two leel from tho crown to the Ulifonn ends ol' llie root. !( Iia.s imnsiiajly loiij; twists, aini (ho joints iiicroiiso coiiiinnally in Ienj,'lli m* they grow wider ; they are oval, ex- cept the two or three proximal ones, whieh are eireidar. 'l"ho lower end of the stem is provided with '-iiri. the upper oC which have a width of .'! mm., tlie lowi'r ones »)f 'J mm. at their proximal ends. The latter, which j;ro\v very slender, are preserved in tlio siiecinien to a length of 10 nun., but woro evidently longer.

Jf>rhiii mil/ Li'i'ii/ih/. — Lower nmlington limestone, Hnrlinglon, Iow:i.

7//JIC in the Mnseiiin of Comparative Zoology.

(I

f

712

Tin: cinxoiDK.v camkhat.v m- xoinii amkrica.

li

PlatycrinuB eminulus iiAir.. rialr LXVIII. I'iiis. J.hi, K c.

ISIil. llvii,; Dixr. New S|HC. iif CriiiiiiiN, |i 17.

A smalliT spi'cios tlian 1'. iri/nlis ; llio dorsal ciii) more sproiidiiiLT, '"id moro distinctly peutiiiij^uliir ; llii" liaso i)ro|i()rtioiiiilly snialiiT ami IJMttor. I'illicr smooili or inmkod liy oI)simiii' coiicfiitric bands paralltd to tlio niar- triii-' of the plates, sometimes si-paratinj^ into di:4inet laeliiTmosi? nodes. Hasi-iiulial and interradial siitnres dei'ply j^roovtul, and the nmrgins of ad- jacent plates lliicki'iu'cl and liiiildy Ijeveled.

Hasals forming a >liallow l>asin. of wliieli the median portions nro rather deeply depressed, and oidv the beveled outer marj^in is visibh- from a side view; inlerbasal sutures rallier distinct, liadials lormiii^' an an;{le of about •I')' witii tlie bottom of" the cup; once and a half — or less — as wide as lonjr. and not (piite one half wider at the top than at <lie bottom. The notches towanl the rciruiar interradial spaces sliiillow, that at tlie anal side consid('ral>ly deep 'r ; the mc(Iian portions stronj^ly thi<'keni'd to lorm the facet, which occupies cbout one thir<l the width of the upper face. The facet is semi-ovate, deeply notched at the upper end. the sinface perfectly flat and directeil horizontally. Cosials almost as Ioul;- as wide, wider at tin- top than at the imttom, the upper angle obtuse. Dislichals. ])a1mars, and post-palmars. two to each order; the plates wider than long, gradually decreasing in size; but the ujipi'i one of each order larger tliaii the lower, wider and also higher. .\rms eight to the ray. given olT as in the preced- ing species ; ipiite heavy, very little tapering, ami curving outwanl. Ventral disk of about the same height as the dtu'sal cup ; composed of a few large j)latos. The orals sharply tumiil ; t!ie posterior one resting between the other four, somewhat larger, and provided with a stronger node. The ambulacral plates large, but smaller than the orals, arranged (|uite regularly in two rows. The interambulacral spaces depressed, formed of three ti-an.s- vcrsi'ly arrangeil ])ieces, of which tlie niiildle one is as large as the orals, but perfectly Hat ; that on the anal side larger and curving longitudinally ; the opening locatecl in the middle of a small, nnnided protuberance, composed of small Jiieces.

JJurhun iiiitl l.iirnHlij. — Lower Burlington limestone, Bmlington, Iowa.

%\'-'

^H

"ft:

I

I

ri.ArvuMNiD.i:.

713

V4r

%

DISCOID E US O IIU I j:

Dorfal Clip low bnsin-slirtped, tlio rudiiils (ind nriii-' s[iroiuliiig almost liorizoiitiilly outwiinl; tlic nnns reinirviny over tin' ilisU.

Platycrinus discoideus '». inul sm m. I'liil, in. F;,j. j:, a,id I'Mc LXVI. Fills. 10,1, h, c.

b'l.'. 0«i N .iiiil Sin MMiii; I'. S. (ii'cil. Siiii. \\ i.e., liiwa iiiiil Minn., |i. ri>>^, I'liitc 'i./, Tiirs. 1./, /,. l'>sl. \\. ;iriil Si'.; Iii\i>inii ruhioi'iv, I'url II., p. 71 (I'lni., cl. AchI, .\;iI Sci. I'liilu., 21'.).

Sui. /• .•nrni,/,i/ii- (). .■mil Sill M , IS.V,' ; 1.'. S. {m.iI. Snrv. \'Mn, WIm'. :>ii<I .Minn , v. ,'iS;), I'j.ite

."»./, Ki^H. :?./-*■. (ill. I /'/. .//■,v,-.,(./f«« llil.l., ls.-,S; ficil. Itr|.. |..\v:i, Vnl. 1,, I'art II., |, j'M, I'hW s, KL-s. s.,,, /, = E'li-Iti'luft-iii/i^ /t/'ttnii'tuiintt.* W'iiili).

Svil. /' th'inln-ilflliiihii Ham., IMll ; l)|.sri'. N'i.«- SpiT. t'lill., |V. \; iiIm) Hi,..1iii1 .liHiril. N.ll. Hist.

I * I ■ ■ I ' •-.-■■"•■ ■' '1. .'■•". ill-..,

p J^; (liiiiiml |s;iiii Hull. N. V, Sl:ili. .\lii> Ni.l. Mist., \'hw i. I'l-v i niiil It (Ti pi- in (•.,ll,c- tlmi (if \V. .'iiiil S|,.). UhiUhld; .\Irin. Am. .Mll^. N.ii. Ili^l., V..I. I. I'.ui I.,' p. 1, I'utc ;t, KiL'i. i I.I I. Syii /'. i,iiillihrii,-lii,ii,(i Mkkk iiiiil W.iUTiiKV, I'lfil; I'roc. Acii.l. N;il, S.'i. I'i.il.i., p. \.\i,

Syil /'. xhunhd-'liltlili II MI,. IS.'iS; C..,,!. H.-p. |.,h;i. V..I. I.. T.-Ill II., p, y.Vi, I'hllr S. Fi..'. .-1. Syil l\ piilrhrHioS. A .Mil. 1.1,11, IMIl ; (u'.il. It.p MisM.lili, Hull, I, p, 11, I'l:,!,. 1, I'l^r. 7,

Cnlj-x pyrniniiliil. wider tlum liiuli ; tlic diii>^al c\\\i di.^^i'uid. almost llaf to tlic iiiidillo of llic radials, llicii cinxiiiir rnpiilly iiiiwards until tlic limli<, wliicli rise far mIiovc tlic lop of tlic facets, stain! at ri,i.;lit angles to tlic plaiic ol tlic hase, i'lali's covci'cd li_v well dedncd corrugations, wliicli in some s|iecimciis arc g.itlicrc.l into imhricatiiig folds covering tlic whole siirf.'ice ; ill oilers arranged In coin-cntric lines confornialdc to tlic sides of tlic iil.ites, IJa^c ]icntiigoiial. with a deep concavilv in the (•cnlr<'. slightly coine.x toward the outer margins, Coluiiiii facet circular; the interhasal sutures inviMld", 1! idiiils almost as long as wide, allowing for the curvature, and near the siini- inil almost twice as wide as at the hase, li'a.lial facet-; l.irgc. lyic-sliapcd. the vertical diameter cipial to one half the length of the plates; the lower rim

projectin._r and on a Icvcd with the hasn]-. 'I'hc siiifu f the facets concave.

aid cov.'i-cd with Sine ndiatiiig sliia' without other markings. IJa^i-radial and intorrailial sutures deeply grooved, the edges of the plates stroii..ilv lievclcd. CosImIs triangular, occupying the full width of the facet. Dis- tichals and palmais twice as wide as higli. .\nns from six to eight to the ray ; one suli.livision in the sjime specimen may have hut throe arms, the other four and exccption.illy five. The anus arc rather stout, simple and liiserial. and are finely striated longitudinally. Disk almost throe times

i

\\ I

ij

I'

ill

Tin; CUINOIDKA CAMKUATA OK XOUTII AMKIIICA.

\l

as high as lla- dorsal ciiii. Aiiiliulacni liiglily fk'vateil, forming lnoail ridges composed of two sories of largo spiiiiform plates altcriiatt'ly arranged, which pass out from between adjoining orals. Orals sjjine-bearing. and larger than the covering pieces; the posterior one larger than the other four. Tnter- radial spaces depressed, composed of five nearly (lat pieces, arranged in two row'.s, all of which are interamhulacral. Tlie middle plate of the first row wry large ; the two at the sidi-s as long as the other, hut niueli narrower. Anus at the summit of a short protutierance. opening out lateially. and placed between the plates of the fii'st and second row, which together with the four smaller orals ami tiie njiper plate of the two posterior nmhulacra form a ring around the larger orals, giving to the latter a strictly central po-ition. Column twisted ; the proximal joint circular, the succeeding ones elliptic ; and increasing in length downward.

Ifi'i-iidii mill Liinilil'i. — Lower IJurlington limestone, Burlington, Iowa, and at the same horizon in New Mi'xico and Missouri.

Jviiiuf/.'s. — This species, although well characterized, is quite variable in details of structure, and has been described under several names, in some .specimens, the corrugations upon the plates are more distinct and coarser than in others, and sometimes are obsolete near the facet. The form of the dorsal cup also varies considerably, being in some specimens much deeper than in uthers, and the outer e<lges of the basal.s rise slightly above the plane of ilie radiaN. Owen and Sliumard's figiu'e of 7'. i/isniii/ii(f< repre- sents iin exirfpicly llat specimen, and its corrugations are very coarse. In their /'. ini-ni;/ii/iis, on the other haixl, the markings are line, and the dorsal cup consiilerably deeper, the two representing the extremes of the sju'cies. Hall's tyjie of I'. s/ri"hnirfii'iitiit. which lias the arms preserved, has the orna- iniiilalion of /'. inrrio/ii/ii.-:. Init the form of/', ilisniiiliiis. In Hall's J'.s/ni- iiiiirili'diii^ the corrng.itions are less conllueiit. and take almost the form of granul's oi- nodes, less marked, however, than indicated by the figure. In /'. iiiu/filiriiiliiii/iis M. and W., the eoriiigations do not exteml to the median portions of the radials. 7'. jiii/rl,i//ii.f is a yoimg specimen of the type of 7*. striiilii'iirliin/iis.

The f//pr of 7". sJiiiiiiiiriJiiiniiif is in the Illinois State colleciion. Spriiigfli'ld. those of /'. striiihfiirliiiit.is miuI 7'. iniillihrniliiiilitK in the .Museum of Com- parative Zoiilogy ; the fate of those of P. illKnilihn^ and /* inrniijutn.i is unknown.

VI

^

rLATYCUIXID.E.

m

PlatycrinuB cavus Mvix. riute LXr/I. FI<js.S,i,b.

1S5S. Kali.; (iml. l{c|i. Icnva, V.il. I., I'.irl 1 1 , |.. .V.>7. I'l.'t.' M, Ki;;s. 1,;, h.

ls<sl. \V. mid Si', i Hrvi»iuii, I'lirt II , ... 71 (rmcml. .\™l. \;il S.'i I'liihi., p. 2i:,)

Of iiiL'diuin size. Dorsal cup saiieer-.sliapcd; tlic l)a'<al disk slijrlitly pro- jecting l)cdi)\v tiic lower inarj^iiis of tlio radials ; llie latter eiirviiii;- ;.;eiiily ujiwards. Tin; facets face soinewliat outward, aud have a >!i.i;lit depres- sion around tiieir lower margins. Surface marked liy concentric; lines of notles or granules, wiiich are sometimes conlluent. There are two or three langes of these nodes parallel to the margins oi' the liasal disk, and similar ranges of nodes surround the radials, leaving a plane space eipial to the granulate portions hetwecn the hitter and the edges of the fiicets. Has!- radial and inierradinl sutures ehann(ded, and the .sides of the plates slightly beveled. Neutral disk high, pyramidal ; the plates moderately convex.

l>asal disk rather largo, concave in the miildle to the width of the stem ; the interbasal sutin'e lines grooved, hut tlie sutures invisihle. Width and length of tile projecting radials as tour to three. Facets projecting, semi- circular; slightly notcheil at the upper end; the surface concave. Costals suiitrigonal, moderately large, occupying the full width of the facets; much wider than high. Distichals rather short; placed ohliipiely against tiie cos- tals, Mud directed outward. The higher orders of brachials are not pre-erved in tlie specimen, but portions of the arms indicate tliat the si)eeies liad from six to eight iirms to the ray, wiiich were comparatively delicate. A'entral disk twice as high as the dorsal cup; the inteiamludiicral spaces depressed, the aml)ulacra rising abruptly above the general surface of the di.^k. Orals iiicoMipletely visible in the specimen, so that their arrangement could not Im; ascertained, but the [liates are lai'ge. Covering nieces alternately arranged in two r(jws ; all eijual in si/e. Interambulacral [ilates .'! ami 12; the two outer ones of tiie lirst row curving outwaril, and the ntiddli' one larger than the others. TJie middle plate of the anid siile soinewli:'! the wide<l and shortest, and its upper margin slightly furrowed by the anus, which is placed low down upon the tlisk an<l directed laterally.

IlnfU'iii ami Lucali/i/. — Lower part of Upper Burlington limestone ; Burlington, Iowa.

'/}/jii in the (Worthen) Illinois Slate cidlection at Springfielil.

t

71(5

TIIK ( UINOIDKA (AMI'. RATA OK XoUTII A.MKHU A.

I!()narJ:s. — Tliis spooien is of tlio typi' of /'. i/ixrnidnin, but llio ilorHiil cup is ilet'iu'r. the facets shorter, seiiii-circiihir instead of lyri^siiiiped, and the limbs do not extend aliove the iieij,'ht of the facets. It also deiiart;! from tiiat species in (lie orna'nentation, and comes from a higher iiori/.on. Tiie description is made from tlu' type specimen sliown in the Iowa Iteport, Plate 8, Fij,'. !(/. wliich is -oniewhat crushed at the base ; figure 1?), on the same plate, is from a dilTerent specimen, which iiuiy be of amxher species.

r

It

Platycriniis Gorbyi s A. Mh.i.ku.

/•A,/, Lxr/ii. f;,j. at.

1S91. S. A. MiLi.i;ii; GoiloijkMl ;>urvc.v uf .Mi>suuru Hull. 4, p. 15, Vl;ilf I., Kis'. U.

In the form of the dorsal cup and the proi)ortions of the plates clo.sely resemliling /'. riirii-\- ; but t' ornanieutation is coarser, anil the radial facets smaller, more projecting, and their faces tiat instead of concave.

Dorsal cup decagonal in a dorsal nsjiect : the ba.sal di.sk projecting ili.s- tinctly below the lower margins of the radials ; the sides of the latter t'X- |iandiiig ra|iidly so as to form a Hat. spreading cup. The ]dates moiK'rately stioMg; their surface covered wilh two irregular rows of rather large nodes, of which the outi'r ones are freipieiitly conlluent. and form an undulated ridge aroun<l the beveled edges of the plates. The basi-radial and inter- radial sutures dee|dy i-hanMeled. Basal disk regulaily pentagonal. Hat around the min'gin, with a slight funnel-shaped depression in the middle; the |iroxi- nial stem jnint iMicular ; interbasal sutures obsolete. IJadials one tliiiil wider tliau long, the ends of their limlis almost on a level with the upper ends of the facets. The t'acets semi-ovate, and but slightly notclied at the upper end ; tlii'V occupy about a third of the width of the plates, and not ipiite one half their length. All other |iarts of the species iniknown.

Jliir'c.mi iiiiil I.nriiH/'/. — T.ower liurlington limestone. Hurlington. Iowa, and Sedalia. Mo.

T>/jie in the collection of Mr. H. A. IJlair o'" Sedalia.

^

TI.ATYCIUMD.K.

17

til

r

'^

Platycrinus subspiDosus Ham,. J'l.itc LXVI. l-'hjs '),tj>.

ISr.S. Ham.: (1...!. liip. |..«:i. Vnl. 1 , |':,il II.. p. .ViCi, I'lliti' ><, I'i'.'H. 0 mill 10. isr.li. Mi.ih Mini WcmniKs; (icnl. It. p llliiinis, \nl, II., p i;:>. I'liiii' l.-|, ri'.-. r,.

Smiiller tlmn /'. disfdli/cn.-! ; its ilor.^iil ciij) Im.-i a siiiiiliir t'onn. Ixit lie .xuifiice of tlio iilntes is Minoolli or very oli.'^ctirely corniirntcd ; tlio vit, nil (li.sk shorter, eoiivex instead of in'raiiiidal, and eomposed of but few large plates; tlie arms iicavier. .shorter, and without striiu.

Hasai ilisU rather small, hroadly and deejtly fiiiniel-shiiiK'd, the excava- tions extending almost to the outer margins. 'J'he iuterhnsal sutures very slightly grooved, hut the hasi-radial and interradial sutures d-jep, and the edges of the plates -trougly heveled. IJadials ahout oiiee and a hall' iis wide as long, anil nearly iwiee as wide at the upper end as at the lnwcr. rising very gradually to tlie facets, whieh project distinetly outward; the li:iilis eurviiig rapidly upward ••ind slightly inwai'd 'I'iie I'aeets, whieii are not tiiicliened around the edges, are dirceted hioi/onlally, and their faces are perfeclly Hal ; tiiey are wider than high and rather large, occujiying nearly two thirds llie width of tlio plates. Costals very large for the genus, and comparatively long ; pentagonal; directed outward and slightly downward, so that the succeiiding distiehals are sometimes at a lower levtd in the sjH'ci- men than either radials or hasals ; the upper angle ([uile ohtuse. Distiidials two; the first (piadrangular ; the second pentangular; hut Iilll<' smaller than the costals, giving olT an arm to the outer side of the ray. and two p.dmars to the inner side; the latter supporting an arm to the inner side, anil two post-pahuai's to the outer, then- heing normally four arms to eaidi main division and eight to the ray, exceptionally six or seven. Arms heavy. nioderat(dy short, rounded on the ha(d\ ; composed of rather long-, slightly convex pieces. Tlioy arc generally outstretcdied to al)out half their lengih. then curve rapidly invvard mitil tlii'ir tips rest \i]ion the outer margins of the tegmen. Disk <leeidedly f|ninfiiieloliate. higher than the dcusal cup; the amliulaeia highly elevated into ridges. Orals very largo, snhsiiinous. occupying one half of the ventral siu'face ; rather regular in their arrange- ment. Disk andmliwra sh<u't. composed of hut few tinnid piece.«. The iiiter- anihulacral spaces small, sonietinn's formed of a ;ii!igle row of throe plates, of which the middle one is (piite large, the outer ones as long hut narrower.

•18

Tin; ( UINOIDK.V C'AMr.KAlA 111' NOinil AMr.UK'A

Tlio liitter L'lirvi' outward to tlio <'()stiil-<, niiil incut (lie Cdvciiiig pieces. Wlicii tlicrc lire imirc tliiiii tliicc pliitc?*, tlic ii])[)cr ones v.yr very suiiill Anns jilii^ il liotwei'u the two posterior oriils. tlie opening direcleii liitcrallv.

//

rc'U

tnitl L'ifiilitii. — I,<.wer Turlington iinieslone; IJurliugton, Iowa,

and Lako A'allcv, Now Mexico,

'I'lJl'i' in tile (Worllicn) Illinois State collei'tion (a rallier poor spccinicn).

Ill iiiiii-l,K. — In a very line specimen, evidi'ntiy ol' this species. I'lalc IjX\'I.. V\,i. 0'/, llierc is an indistinct node within tlic five angles oftlu" lia^al di«l<. and lliree others, even more oiiscine, npon the hevelod edges at tiie lower enil of tiie ladials.

Platycrinns excavatua iim.i.. I'hte L.Wi. I))/..;.

l^i'il. H\i,i. I Di'MT. New S|Mcii'» Ciiji , |i, t: itU, H.isl..ri .I"iirn. Nal. Ili«l., Vnl, VIl , p. ■J-C (liiinroil iNi N. V. SMIr Mil, .\:.l. Ili-l , Hull I , I'luti- i.l. 1-iir 1).

b'j;i Will in I in; M. \iii. Mil,. Nm. Ilisi , V.it. I , I'uri I y. H, l'!,ii- III . Kii:. 5.

S>ii. I'l.iii/.-niiini siil,;ili(i Miri.K.ii, Is'.M ; (u'nl. Surv, Mi,,.iiin, Bull. 4 p. Ill, YU,- i, \\.,. J.

A rather rohii-t , iieiies, not .liiove inediuni size. Dorsal cup discoid, forming a flat ha-ln. Only (Ik- extreme outer mari;in of the hasal di-k |irojecting helow the margin of the radials. the inner portions deeply di- j)ressed so as to emhrace the three or four proximal stem joints, whiidi do not. however, touch the sides of the concavity. The radials expand ver\' ra)iidly. curving hiil liille; their upper faces twice as wide as the lower one-; the lacets suhcirculiir, s(Mnewhat concave, and directed (uitward and slighlly downward. Interhasal sutures ohscure. the hasi-radial and interradial ones profoundly and widely channeled ; the sides of the li;i<.il disk and radials heveled. Outer margins of radials sni'ronnded hy w thickened rim or rugose swelling, anil the facets hy a slight ridge, producing a rather ahrupt depres. sioii in the meilian portions of the plates. Surface of hasals snuioth. Co-tals triangular. frei|uentiy not occu]iying the full width of the ficel ; the distiehals then toucliing the radials. and their sloping upper faces making n right angle. Di-^tiehals two; the lower one twice as wide ns long; the iippei' wider than the lower, the upjier angle ohtuse. Arms four to tlu' ray. \ery stout and short, sliglitly tapering at the tips. Structure of the ventral di-k unknown, except that the aims was at the end of a tidie which extended to tiio full height of the arms, ami was composed ol' spinifon.i jilates.

lL'il::i'a and L'nUdi). — Lower Burlington limestone. IJurlington. Iowa.

J

I'LATYCUINinK,

71!I

Original ////» wiiid In he in the Wliite collection iil Ann AiImh', Miiii., Imt not certiunl_)' idi^ntilied.

Ill Hill lis, — OiU' clesL'i'i|ition was niiule I'lom the (|iiile jierfeet s|)eeiiiien (ijjnreil (111 Piute fiW'I.. l•'iJ,^ 1. wiiicii we have ifU'iitilied ms liidtinyinjj; tn thi.-t Hpucle-'. ultlion^jli niiich smaller tiian Hall's t}'pe. and the s[ieciinuii lij.nii'i'd l)y Miller as the tvpc ul' /'. sulivtim. The specimen (Ij^ured Uy Whitlield as Hall's type is somewhat inipeifeet in the hasal disk; the very larj,'e |)entapet- iilons opening in the centre is dui.- to accident, as no /'/iih/iriiiii.\ in its normal cimdiiion had an opening in the hase for the central canal of any sucli size or shape as the lignro shows. The species is interesting' us lieing the lirst authenlic r/uf'/iriini.-: in America in wlii(di a lung anal tnhe has heen olisei'ved. It is plainly shown in our specimen, hut is hripkeu oil' just within the lips of the arms, and does not appear from the view giscn in our fiifure.

EUCLADOCRINUS Mii'k (.incMilci \V. an.l Sr.).

1^71. Mn K : t,' S. (iiiil. Surny mI' Mi.uliin.i liy IliiMliii. |i .'t;:!

l-rv \\. :iii<l S|.. ; I'm (I \,'w\ N.I. Si'i. I'iiilii ,"|i. -ill, :.ij.l Msl, HrvM„ii, l';irl II., p. Tfl (I'rn.w.l

Ao:iil. N;il .Sri I'liilii., |i. iM) Isyo. S. \. Mii.l.i h; .v.. nil Aimr. (i.-..!. mii.I I'alu-.nl.. \> 2H. Sjll. /V./A/.V(«". (ill inirl) llo.l. IS.-iS; Wllllt l>'li-.>.

Construction of the dorsal cup. ventral ilisk and colunni. as in riiifi/i-riiin.^. hut the hrachials exiendeil outward and toiiuing lar;;e tnhular appendages or arm trunks, whitdi pass out from the caly.x. and givi' ofV the aims alter- nately from opposite sides, These trunks are extensions of the calyx, com- ])osed of II greater or less nnndier of successive (U'ders of liraehials, of two plates to eai'h onler; liiey are roofed over hy large, rigid, or ni.irly rii;id. covering plates throughout their whole length, forming a good si/.eil tnhular passage underneath, which commuincates with the innei' part of the calyx. There are generally two such trunks to the ray, which are in contact to near tiie ti>p of the [lalmai's. and support a single arm from excry axillary. Some species, howcNcr, have hut one appendage to the ray. and their arms are uiven off ii\ clusters of four or more from evrrv second lirachial. The arms are of moderate si/e, hiserial and pinnule-hearinn-. hut were apiiareiilly shoit, and the lowt'r ones did not rise to the top of the crown.

I)!filr!''iili'in. — IJestrictiMl. so far as known, to the upper part of the Rurlington and the lower heds of the Keokuk groups of .\merica. y'l/jii of the genus; Eiii-liiihirr'niiis iiioiiIiiiuiikIx Meek.

Illi; ( IflNttllH.A CAMMiAIA dl' NoIMIl A.\li;l!U A.

; i

lit murk. t. — 'I'liix gi'iiUH Ijoiirs tin- wiim.' relation ti) J'/nli/rriiiiin that S/ii/<i- luirrinii-i (loos to Af/iii'irniin.'t. In Ijoili j^nnipi tin- I'liys hnincli in llu-ir IVi'i' Mtati' ; l)iit wliilo in l'/'il//iriiiiiK ami Arlliinirliiis liu' rovi-rin;^ platox aiv luiivalilo IVoni llii' co-iiiiU iip, llicy aii- in -ntnial contact in Kiirliidnvriiiiis ami Sfn/iiiiiiffliiiis to llic ciul ol' tlic appcnilagi',-*, and liic latter jnaclicaliy I'orni i'\lcn>ion-< ol" lliL' cai_\ \.

In rart II. of llu' l!cvi>i(Mi wi- placed lunlci' this i^cnus only tlu).>'c specio in wliicli llio aim trnids-i i'\tcnil lo llic lull lici;4lil of tlic cinwii, ami in wliicli till' anas arc jrivcn oil" singly t'ldni opposite sides. 'I'liis cNclndcd such loiin» as •• I'/ii/i/rriiiii''" /'/■/./»////'"> and " J'/n/'/friims" hiln i-'isns, which have inii|iiesiional)ly the clni'aetoiistics ol' h'luhi'li'iriiws, but k'ss cuniplotely developod.

Eiicladocrinus millobrachiatus vv. ami Sc.

I'/o/r /..v.Y///. /•';/. /. '^"/ /'A,/, A.VA/r. /•';-/>. .'. .;. .;. .7. (;, 7. s. n.

!»>. \V :ni.l Sr, ; I'p.c'i',1 Aim.! Nm. Sci I'liila.. p. iU. :iii>l bM, |{.\isi..ii, |';,ii 1| , p. ;; (IVnn'iil. Ai.ul. Ni.l. Sri I'liila. |i. -'.-.I).

A ralher lai',u'e sprcii's. resendilinj;' I'/dli/friiuis ij/'/jitiia in the I'onn of the calyx and «!yle of oinainentation. Dofsal cup hell-.sha|)ed. a little lii}:hei' than widi'. ihe rays extended outward and loiniini; aliove the distichals ten pondeious tnhnlar appendajjes, two to the lay. which. cnr\in<.' downward, expose the vi'iilial sinhice. and jjivo oil simple aims to iieai'ly the full heijjhl of the crown. N'eiitral disk vi'ry short and llalleiu'd on the top. Surface ol lia^aN and ladiaN marked liy row-* of small nodes aiicl rnii'ose ridjres. ariiiMjied parallel to (he maij;'ins of the pli.tes. and radiatinjr to their angles.

IJasals roriniuy a s.Lncer-sliapt'd dish, eipial in height to one third the length of the dorsal cup, truncatiM] at the holtom. the middle portions de-

pie 1 to the widih of ihe coliunn: the interliasal sutures invisible. l!adial>

longer than wiile. very >liglilly increasing in width upward, a little gihhous ill liie middle, ami swelling toward the facets: the edges of the plates not lpe\eled. and the interradial suture lines ill-delined. Facets large, semi- circular, facing almost horizontally outward, occupying two thirds the width of the plates and ni'arly one third their height; the surface slightly pitied in the middle. Cosials very sliort lint wide, lilling the entire siirfai'c of the

f I-. ami aliiilting against the lowi'i' end ol" the interradial plates; the

di^lal face.s, although the plates are axillary. aliiio<t parallel with the proxi-

li

■■i&-

I'l.ATVdIIMD.r..

721

I-

1^

iiiiil fnce, Imviii^ only a Hiniill niigiilar projcotion iit l!i" iiu'iliini lino. Dif ticliiil.-i two, mIioiI, four (iiiii's us wide n-* liij^li, lliosc of the Mime niv HUtuniily I'onnecteil us far un the midille ol' the Mcund jihite, whieli latter gives oiT an arm tci ihi' outer xitlu of llu' ray. The Huceeeiliiig orders of brachials furiii the dormil nido of the niipuiida^^es ; tla y an iiiinposed of an iiidelinile niiinher of successive orders of two plalcs eacli. of wiiidi every seconil plate is an axillary, thus K'\'"n "'^ alternately from the one side an nrn>, and from the other the next order of brachials. The arm-liearinj,' faces are much tlie -liorti'sl, and slope altrupily downward; the olhcrs funii a nearly hori/.oiilal line, so that the plates of the n])pcudMj.'es an? transverse but not exaetly parallid, as the axillaries aro slightly eiuieale. The trunks are three to four times thick'-r than the arms; they decrea.se I>ut little in size upwards, and tcnninale in two sIkiiI arms; the plates are of nearly the name length, about three times as wide as long, rounded on the bacU, and transversely angular at the outer faces. The length of the arms cannot be accurately ascertained from the s|)eciiiV'ns. but it appears as if the prosiiual ones did not rise to the top of the crown ; they are biserial, of niixlerate Hizo, iiinnule-beariug, and they decrease slightly in width upwards. The jiroxinial nrni jilntes are rather deeply set into the rny. and while they rest ciiielly upon the cuncMle axillary, llu'y abut also agains die adjoining (ilates above and bidow, which are truncated for theii- reception. In one of the specimens, the arms near the calyx touch live plates, but higher up only four, which is the general rule. The arms are very numerous ; in a speci- men of medium si/e we counled twenty-foiu' arms to one branch, but the extreme end is not preserved; and we have reason to believe that they averaged in largo specimens at least ten more, which would make about tliiriyfive to the half ray, or throe hundred and fifty to the individual. IJi'iioath each arm, within the appendngos. there are two well defined respi- ratory i)ores, one piercing the upper edge of the arm facet and lower end of the node-bearing plate above, the other placed at the angle formed bj' the same plate and two adjoining bnichiiils.

Ventral disk depressed, the orals modei'ately large, almost central, and tlie middle pnit of tlio [dates elevated into rounded, papillate nodes with rougliened or wrinkled surfaces ; the node of the posterior orid largest. Intorambuliu'ral plates ilat and without surface markings ; they generally consist of four <il)loiig plates, of which the three of tlie first row are exposed in a side view, only their upper ends, which bend abruptly inward, being

roo

Till". (Hixoinrv (.\MrnATA ui Noriiii ami:iika.

Iiidilon. Tlio covoi'ing pIntoK of iho niiil)iiliicrit |ii'i)i>(>tMl tVoni tli<' oittor niiKm til' tin- oriilf" lo till' fnil" i)f jIio nppciuliijfi'H ; tlicy lUf Kiifiriillv I'oimcrit'il llii'dii^'liiiiit llii'ir lull It'ii^rtli. Mini loriii, lugi'tlicr uitli llic philrs iil° the (|iir<<al xiilt', nliiio'^t rigid tiibi'^. TIiuhi' uI' (Ik- (link ino !iii'^i>, at long iix wiilo, iiitil tlu'ir FiiirriiccN Hal ; tlioxv ol' the appcixla^'i'^ in part arc oovcinl wiili Mtnui^ nitiK's. 'I'lic plate ovi>i'l}'ing tliu coxtalA, IVoni wliicli tliu liifinration of tlio aiiiliiilarra taki'x |ilaoi'. \* large :i>vl nodoti'. It in niicrofilcd li_v two rowM nl" trancvfiso plaifw nl' iiivgular •<']/>'. cf wliicli llio larger onon aic {•rowi.cd liy nudi'!4 Hiiiiilar tu tlio^u upon tiic oi'al.<«, Imt niuro pi'ouiini'nt, and witli coai'Mcr nittikings; tliey nil' ananged tiaUHVoiM-ly, like t)io plnti'» lioaring tliom. 'I'lio larger plates an- ><> di-ipn-ii'il that llu-re in oiii' nt the hane <>f eacli arm, and liy ronnting tin- nodcv llic niiiiilpur of llie arinn i ,in lie nicortaiii' d from tlii'ni a> readily an from llie liraoliials. Iteiween every two mxla! platen are two or three riuialler onen, wliieli are Hat. except lor the genonil curva- ture. Aiiun low down, faeiiig laterally. Column large and long, iipidly twisting J the pro\imaI joint eir'Milar, the nneceeding ones turning ahruplly into eiougMte-elliptie — tin- long diameter twice the nhorter one — and tlieii' longitudinal ihicknenn iiicrenning an they recede from the calyx. Kacli joint in twisted no tliat the long axes of its reverno facen make a oonnideralde angle with each other; ihe other rim in heveled to an edge, from which small tooth-like spines |)roceed imtwanl. The articular lidgc well (lefincd, and honlereii at the niden liy deep fonna\ Axial canal e.xtromely nimill.

Jliifl'mi iiii'l f,iii(i/ifi/. — Transition hed hetween the I'pper IJurlingtoii and Keokuk heds ; near Ituilinglon and at Pleasant drove. Iowa. Also in the lower part of the Kiokuk /unjnr at Niota and N'auvoo, 111.

7'iijiis in the collection of Wachnmnth and .Springer.

Eucladocrinus millobraohiatiis v:ir. immaturus w m\<\ si>. J'/oIr AAA'///. ^V. 2, 3.

There occur at Burlington in the same hed with Einliiihrrhvin millc- hi-<tihiiitits very much smaller specimens, whiidi are no closely nimilar to that species that they may reiiresent its younger form; hut an no intermediate stages have liecn discovered, and the gap is rather wide, we deem it advin- ahle to place them at present as a variety under that species. The cnlyx' in these specimens, of which we ohtained five examples in excellent [ircicrva- lion, is luiich shorter than wide, the dorsal cup paucer-.sjiaped. the bnnnl disk

T

ri,ATY( IIIMK r.

728

iiliMu^t lliit, iiihI ruvi'ii'il witti iii>li<tiiu>t ii<

wllilc llir I'lliliilN, wllit'll lU'U

wiclcr lliiiii liiii^r, lire I'titiich ^iiiiniili

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ic nilNcmi' niiiiiii(lii^,'i"<, which in

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line of till III iliv prcNfrVLMl to lln' ili-lal ciiil, lii'iil' liiit liru'li.-)'ll iillll^ ill lliu lin'm'^t HjH'ciini'ii, wliicli iin- |iro|i(»i'liiiiiiill)' iiillii-r wiilily Hopuiiilui' !• nil ittlicr rr^|»'Cf«. llic form in i|iu'Mti<iii aurei"* willi A', inil/iltrni liiulr . 1j .»l.'"h it Im'.-i'i iiIkiiiI ilic ••nine I'flaliiiii a.'* S/ii/iiiiii,;iiiiis iirniiititiiH to i. :.• ii'ii^/dhhh.

//../•/'tii/i mill l.iiiiiliti/, — Itiirlingtoii uinl Kuokiik TraiiMtiJii bud, near niir!iii<;luii, Iowa.

Tjjiii ill till' c'lillictioii of Waclismiitii and S|iiin>;('r.

EucladocrinuB moDtanoiiHiM Mmk.

J'lak AAA//. /Vy. J.

l"*,'!. Mrru; Ilnyilfii'i K.'|i. f, S (i.ul. Sun ..I MmiIhhh, p. 3;:l.

nnrj<iil cup appiu'i'iilly mibovnid, ii liltlo lii^jlicr tlian wide, vvidi't't at llic nrin Iiiki-i. SuiIih'i' of platci siiionlli. na^c lia^in-^iiaiicd, foniiiiij; nearly one tliii'd the liei^'lil of llio dorsal cii|>. UadiaU suliiiiiadraii^^iiiar. a little Ion;;!'!- than wide, Klij;hlly upreadinj; ; the lower faec ii litilf convex; the ii|i|ier nn^rk'x Homcwhat tnincaled. Facets nioderatily deep, their width aliont eipial to the width of the radiaN. Coslals very fliort. sn|iportinu' fwo rather KJeinler appendages, composed of nniiierons l^acliials of successive orders, of two plates eai'li, which iVoin the second plate respectively jrive olT the iirnis. Anns roundnl at the dor-al side. Iiiserial anil pinniiledioarinj;. .Ml oilier parts of the species unknown.

Iluri-.iiii iiiiil l.iiviiUlii. — Sniicarlionil'en II" ; Molilalia (the exact locality not lieinjr jrivenl.

7'///"' in llie ."Smithsonian Institution. No. 7S(l5.

It'iii'iiL^. — This species proliahly reseinhlcs Kiifliffiirri'iiiin viUfifirnc/iiiitiin W. and .*^p. ; lint the plates are not ornamenteil. the app. i'dajjes ,'ein to have lieen more slender ami erect. It w;is dcsciihed iVom a .•<inj{le very inipeili'cl specimen, in which the liase is liadly distorted, and only small portions of the calycine appendnj^os are prescrvcil ; tliese. liowexor, show the structural pecnliaritie.s of the ^.'I'lins. while the sin'cinieii is loo imperfect to mlinit of an accnrale specific description.

IMAGE EVALUATION TEST TARGET (MT-3)

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Photographic

Sciences Corporation

23 WEST MAIN STREET

WEBSTER, N.Y. 14S80

(716)872-4503

724

THE CRINOIDEA CAMERATA OF NORTH AMERICA.

i^

1 SI PI

Euoladocrlnus pleuroTlminus White. Plate LXXIII. Fig. 4, Plate LXXIV. Fhj. 1.

lSfi2. PlalyiTiima pteiirorimiiiiin — Wiiitk; I'lMcrcil. Bost. Soc. Niit. Hist., Vul. IV., p. 17.

1S73. EaclwluerbiKa iileiiruviiiiiiiia — W. iirid Sp. ; I'roCL'cd. Acad. Xat. Sci. I'liila., j). 2U, niul 1881, Re- vision, Part II., ]). 77. Syii. Pliili/(-riims iliscoiileiis II.vi.i.! IS.18 (iiul Owen and Sliuu. 1S52) ; Gcul. Upp. Iowa, Vol. I., Tait II,, |). 5;)5, Phte 8, 1'igs. 8(/, b.

A very large species ; the calyx sometimes reaching a width of CO mm. The form of the dorsal cup extremely variable, from discoid to low cup- .shapcd, and from distinctly decangular in its dorsal aspect to almost circular; its height in some of the specimens scarcely a tliird of the width, in others equal to one half. Plates of the cup very heavy, and frequently higidy ornn^ mented over the whole surface, sometimes only around the margins; while in some cases they are almost devoid of any surface markings wiiatever. In most of the specimens, however, the surface is covered by irregular wrinkles and rugose ridges parallel to the margins of the plates, and similar ridges pass from the lower edge of the radial facets to the inferior angles of the radials, and from the coUnnn to tiie upper angles of the basals. Other specimens have a broad, roughened single ridge at some distance from the margins of the plates, and deep grooves at either side of it ; but in all of them the edges of the plates are distinctly beveled, and the basi-radial and interradial suture lines channeled. Ventral disk as high as the dorsal cup, and some- times a little higher, its outer margin rising almost vertically from the upper edges of the radials; the median portions depre.s.sed. The species has ten arm trunks given off from the radials almost iiorizontally, those of the .same ray being in sutural contact to the top of the first palmars ; they are quite heavy at the proximal end, but taper gradually upward, and curve gently from above the palmars upwards and inwards, supporting from the side of every second plate a simple arm.

Base pentagonal, with a funnel-chapcd depression occup3'ing two thirds the diameter of the plate, the margin convex and on a level with the beveled lower end of the radials. The interbasal suture lines more or less deeply grooved, the basi-radial and interradial ones at the bottom of a broad, shal- low channel. Rpdials moderately spreading, the lower face wider than the laterfil ones, the upper end slightly inflected to meet the interani.bulacral plates, and the angles broadly truncated for their reception ; the plates

III

mma

J A' "-IIP-"

PLATYCRIMD7E.

725

I

are thickened around the facets, which project considerably and face almost horizontally. Facets concave, semicircular, the 8>u'face crenidated at the margin, their midillo portions distinctly granular, the upper end provided with shallow fossa" ; the distal faces directed obliquely outward and support- ing a large covering plate at each side of the ainbulacral passage. Costals depressed pentagonal, five to six times as wide as hmg, the upper angles obtuse. Distichals as long as the costals at the median line, those of the same ray interlocking laterally with each other and with the palmnrs above ; the axillary rhomboidal, the arm-bearing face directed obliquely to the side, the opposite one horizontally. The palmars have the same form as the dis- tichals, but are a little shorter. Plates of the succeeding orders more cunoate and less regular in their arrangement ; the axillaries upwards from the fourth or fifth order decidedly triangular, while the plate below is but little higher at one side than at the other, an arrangement which gives to the iipper part of the trunks a waving outline. The arms are set deeply into the trunks, and their two or three proximal plates actually form part of them, being suturally attached to the sides of four or five brachials, which are truncated for their reception. The arms are directed obliquely upwards, are biscrial from the second plate, thicke" at the proximal ends than at the distal, and they are not very long, the lower ones not rising to the top of the crown. The ventral covering of the ajipendages has not been observed in this species, being hidden by the arms, but the transverse section shows that it was similar to that of E. mUlehrachintm.

Ventral disk composed of comparatively few, large, very heavy and con- vex plates, among which the posterior oral occupies the central part. This is surrounded by eight plates of nearly the same size, viz., the four other orals, the proximal covering pieces of the posterior ambulacra, and two plates, which, together with two others of equal si/e, form a protuberance enclosing the anal opening. The covering pieces ire large, but decrease somewhat in size as they approach the appendages. There are but three interambulacral plates in this species, transversely arranged, of which the middle one, although less convex than the other disk plates, is larger than liny of them ; it is hexagonal, somewhat elongate, concave at the sides, and it stands erect, being completely visible in a side view.

Column similar to that of E. millchmehktm,\>nt\i\{\\o\\t nodes ; the lonw diameter of the joints proportionally greater, and the twist more rapid than in that species. The joints increase in length rather rapidly near the calyx,

1

r2C

TIIK CRINOIDEA CAMEUATA OF XUUllI AMKUICA.

but lesH so toward the root, and from Btein fragments wo liavo seen \vc judge that the stem must liave been quite long.

Ilurlxon (Old Lwalili). — Upper Burlington limestone, Burlington and Augusta, Iowa.

Tiipc in tl'.e Wiiite collection at Ann Arbor, Mich.

Jieinar/i — Thi,s is one of the most magnificent known species of Camer- ate Crinoids, and one of tlie two finest specimens of it ever found at Bur- lin^rton is in the British Museum.

Eucladocrinus prsenuntius w. and Si>. Plate LXXIII. Fig. 5.

1S7S. PUili/mmm yirmunlUis — W. nnd Si'. ; I'l-ucced. Aciul. >i'ut. Sci. Thilr., p. 249, Plntc 2, Figs. 1 niiJ 2 ; also llcvisiou, I'lirt IF., p. 71.

Of the type of Eudmlocnnus platrovimimis, but .smaller, the tubular extensions from the caly.x much shorter, and giving oft' less than half the number of arms. Dor.«al cup saucer-shaped, its sides sharply angular. The lower part ot the radials projecting over the deeply excavated basal disk, and not visible in a side view, or only the points of the angles visible, which are thickened and formed into rounded nodes. The margins of the radials are surrounded by a broad, thickened, rugo.se rim ; while the space around the facets is depressed and without markings. The edges of the plates are profoundly beveled, producing deep channels all along the basi-radial and iuterradial sutures.

Basal disk pentangular, very deeply funnel-shaped below ; the sides slightly concave ; suture lines invisible. Eadials rapidly spreading, twice as wide i's long, moderately curving; the truncated upper faces but little slop- ing toward the regular interradial spaces, rather deeply at the anal side. Facet projecting, facing outward, semicircular, concave, very slightly notched at the upper end; the extreme outer margins striated. Costals wedge-.shaped, not extending to the full depth of the facet. Distichals two, both quad- rangular ; the .second narrower on top than at the bottom, its lateral outer face giving off an arm to the side, the lateral inner face suturally united with that of its fellow of the adjoining division. The horizontal upper face sup- ports four or five successive orders of brachials, each one consisting of two rather large pieces, and the upper one irregularly axillary ; one of the sides sloping and giving off an arm, the upper face the next order of brachials.

rLATYCRIXin.K.

727

Arms from six to seven to cnch main division, or twelve to fourteen to the rny ; thej stretch outwnrd to the length of the piilinnrs, and then bend upward and inward, being rounded on the back, (lattened at the sides, and biserial from the second joint.

Ventral disk fully twice as high as the dorsal cup, rather bulging; the plates large, heavy, and highly convex. Orals in contact laterally ; the posterior one central in position and larger than the others, which are o))long and pushed to the anterior side. The fixed covering plates of the ambulacra extend out from the orals beyond the limits of the calyx to about one half the length of the arms, and form together with the different orders of brachials large, tapering, tvibular trunks, from which the arms are given off alternately at the sides. Interambulacral plates : 3, 2, 1, all large, but especially the middle one of the first row. At the anal side the middle plate is still larger, and is followed by nine or ten small plates, which take the place of the second row of plates at the other sides, and form a small pro- tuberance enclosing the anus. Above these plates there are two larger ones, which, together with the smaller orals, form a ring around the pos- terior one. Anal opening directed laterally. Stem elliptical, rapidly twist- ing, its long diameter nearly three times the shorter one; the joints slightly increasing in width, and their proximal and distal faces provided with a well defined ridge.

Horizon and Locnlity. — Lower part of the Upper Burlington limestone, Burlington, Iowa, and several places in Missouri.

Types in the collection of Wachsmuth and Springer.

licmar/cs. — This and the next species have the characters of the genus less pronounced than in the typical forms, and they represent transition forms in different degrees from Platycrinus.

'i

728

llIK CUIXUIDKA CAMKUATA OK .NOIMII A.MKliKA.

i

Euoladoorinus tuberosus (il.M.t.). r/ak LXXII. Fi<js. J, 4 a, b, c.

1S.)S. riiifi/friiim liitirro'iis~\\>.\.\.; Gcnl. l(i'|i. linvn, Vol. I., I'iii-t II., p. W.W, Vliilo 8, Fi'rs. la, h. ISbl. I'liili/i'i-iiim lii/irrusiis— W. iiiiil Sf. ; Ui'visiciii, Tart II., p, 7C> (I'rnc. .Viviil. Nut S'i. I'liil., p. i.jO). Svn. Pliili/miiia um.h.it.i/i- ;>. .\. .Mii.i.KK, IS")! ; (ifiil. Siirv. Misxiuri, liiill. t, p. 10, I'liili' 1, l''ij,'s. 5, 0.

Ctilyx wider flian liigli, Iicini.'<plieric to subjiymmidal, slightly peiitangiilnr in outliiio. Dorsal cup di.scoid and very short, re.sting on the projecting margins of the radial facets; the lower edges of the facetij directed slightly downward, the limbs bending upward at a right angle. Ventral disk .>'oine- what bulging at the posterior side, and portions of the interambulacral j)lates visible from a dorsal aspect. Plates tiiin, without ornamentation, and very little elevated ; the suture-i slightly grooved. This species, in the form of its brachial trunks, of which there is but one to the ray, and in the arrangement of its arms, which are extremely short and given off in clusters from the sides of the trunks, resembles certain species of Oni/cJiocrlinis.

Basal disk proportionally small, with a small depression in the middle for the proximal colunm joint. Interbasal sutures oljsoleto. Radials subhex- ngonal, lying horizontally to near the facets, whore they are twice as wide a-^ at the bottom. The facets occupy less than half the width of the plates ; they are semi-elliptical, greatly projecting, directed more or less obliquely downward ; they are deeper excavated in the miildle, and the margin is obscurely striated. Calycine appendages heavy but slu)rt, their transverse section olilong. They are directed obliquely downward to their full length, and are composed of five successive orders of brachial.;, whicii give off arms from the outer sides. The different orders, except the costals, consist of two plates each, and are roofed by two series of rigid, very large covering pieces. Costals extremely large, reacliing a length of 0 to 7 mm. ; they .re rounded on the back, the sides abruptly curving inward, and the distal faces, although axillary, almost straight. Distiehals 2 X 2, a little wider than long and quadrangular; the second pentangular and irregidarly axillary. The latter plates give off 2 X 2 X 2 palmar.s, of which the outer ones support a cluster of arms; while the inner ones take part in the calycine appendages. The lower plates of the outer series are trigonal, and rest upon the sloping upper faces of the distiehals and against the sloping lov.-er faces of the inner palmars

PLATYCRINID.E. 729

in such a manner, that the direction of tlie arms is at riglit angles to thi- trunks. The second pahnars of the inner sides support two orders of post- palmars, tiie lower one giving olT one arm, the upper two. One of the latter arms hranches again in its biserial stage so that there are four arms to each cluster. Similar sets of arms are given off from the fourth order of brachials at both sides of the trunks, and also from the distal end.

The plates of the ventral disk are comparatively large and rather promi- nent; the posterior oral moie elevated than any of the rest, and slightly excentric, leaning to the posterior side ; the four others somewhat smaller; all sharply angular and sometimes spiniferous at their summits. The cover- ing pieces of the disk are quite regularly arranged in two rows. Interambu- lacral plates : 3, 2, 1 ; the middle one of the first range almost as large as the posterior oral, and the corresponding plate of the anal side even larger. Column rather small for the species, the long diameter of the joints not more than once and a half that of the shorter one ; the pro.vimal joint cir- cular, and those succeeding it increasing moderately in length.

Horizon ami Localitij. — Upper Burlington limestone, Burlington, Iowa, and Sedalia, Mo.

Ti'pe in the (Worthen) Illinois State collection, Springfield.

Ilenuirlxs. — This species departs in its arm structure from all other known Platycrinoids, and also is readily identified by the form of the dorsal cup. There is no other species known from the Burlington limestone in which the arm facets are directed downward, and in which the calyx rests upon the projecting edges of tlie radial facets ; nor any in which the basal disk is so small proportionally as in this species. It is extremely rare, and was always recognized with ease by the Burlington collectors; but one specimen has ever been found showing the structure of the arms, and that is the crushed specimen in our own collection, which we have figured.

I

>'<!

92

730

THE CUlXOinEA CAMERATA 01' NOKTII AMEHICA.

ItM.

1S57. 181)0. 1S78. 1879. I'iSl. IS'JU.

MARSUPIOCRINUS riuLi,.

(Not .Viimi/ji'viiiitct Bi.Ai.vvir.i.K ^--- Miimi/ji/i:< Manx., nor Maraupiocrinilet llill'= fyriocriiim).

I'liH.i.ii's npiul MniciMsdv ; Siliir. Svsluiii, p. (172.

Aisns J Aim. ami Xliig, Niil. Ili>l., Vul. X., p. lUO.

I'liTi.T; Triiili'. lie I'liliuul., Vul. IV., p. 'i:ii.

DrjAUiiiN 1111(1 Ilri't; llisl. iiiilurcllc iles Zoophytes, p. 119.

Anoki.i.n ; li'du. Ciiiioiil. Suoo., p. i.

ZiriKi.; lliindl). iliT I'alifuiil., Vol. I., p. .'105.

W. ami Si'. ; UcvisI riii-l II,, p. Hi' (I'lnoicil. Acad. Nut. Sci. I'lilln. p. SM),

S. A. Mii.i.eH; North Aiiii'i'. (ii'nl. ami I'alii'oiit., p. Mi),

Syii. I'liili/i'riims (In part) — F. Uukmeh, ISIlll; Siliir. l'"aiiiiii AVcsl. Ti'iiii., p. 35. Syn. Ciiiiflhirriiiiis — TiiiinsT; 1>>50, List Crlii. Ti'im., p. 61; doscrlhcd by Shum, ISOBj Cut. I'uhi'u/.. Fossils (Tiaiis. St. Louis Acad. Sci., Vol. II., p. 301).

Closely rcliitcd to Plat/iorlniis, but tiio lower brachials and the first plate of the iiiterradiiil series entering; rather more into the dor.sal cup ; the radial fiiccta, Instead of being excavated, are nearly straight; the column circular instead of elliptic ; and the axial canal very much larger and pentagonal.

Dasals arranged as in Plali/cr'nuiii, and similarly anch3'losed. Radials largo, hexagonal in outline ; tlie upper face supports not only the costals but also the disticiials ; it is straight, or slightly indented for the reception of each plate. Costals one, very small and trigouid. Distichtils one when there is another bifurcation above ; they are siiudl, resting with their lower faces upon the radials, with one of their lateral faces against a large interbrachitil plate, and at the oppo.sito side against the adjoining distichal of the same ray. Anns from two to (bur to the ray, rather stout and biserial ; the pinnules large. Ventral disk hemispheric ; the orals rather small, pushed anteriorly, and quite asj-iumctrieally arranged. The ambulticral i)latcs con- sist of regular rows of covering pieces, which l)riinch upon the disk, and are separated from those of adjoining rays by rather large interamliulacral plates, and the branches from one another by one or two interaxillaries. Column of uniform .size throughout, and, ,«o far as oihserved, without cirri, except periiaps at the extreme end. The joints circular, each pair of nodal joints enclosing an internodal ; the axial canal moderately large and pentagoiiiil.

DistrUnd'ion. — The genus occurs in Europe as well as America, and is restricted to the upper Silurian.

Tijpe of the genus : Jfarsiijjiocrimis ccdatiis Phill.

Remad:s. — Among his list of the Crinoidea of Tennessee, Troost gives under CiqwUct'cniuis the following species: CupdlcKrhius Buehi, C. coiruffoius,

<^

«)»

rLATYCUINIDJ:.

781

C. wjlatiis, C. Iwris, C. moyvlficm, C. jiaihiyoiuilin, C. riiKufunnlx, C. sltlludis, und C. atiiMtm,— o.\\ fioin Dociitiir Co., Westurn Tuniieswec — wliich in all probability arc mere variotiea of M<iitiiij>hivrhius lriiiiisn(it,.si!i (Iiouiiier). A ligiiro of tlic VL'iitnil side of M. ilrprcssiin Aug., from tbe I'liiicr Silurian of Gotland, Sweden, is given on Plate HI., Fig. li.'i.

Marsupioorinus tennesBeensis (Roemku). Plate LXX V. Fi<js. lOa, b.

ISfiO. Pla/^mniis lennmrciixis — Wn.WY.v.; Siliir. Fimim West. Trnn,, p. ;15, ri.ilc 3, Fi(»s. -U, h, e,

(I, f,f. BSl. Mumiiiim-i-iiiiis /niiirsmmh — W. mid Sr. ; Uuvisioii., rurt II., p. 155 ( I'rocfcd. Aniil. Niil. Sei.

riiiiii., ji. 2;i'j).

A rather large species. Calyx greatly depressed, its width about twice its height, the latter equally divided between cup and tcgmen. Dor.<al cup saucer-shaped, the base Hat, the sides slightly convex, rapidly spreading, riatos moderately thin and flat, the ornamentation somewhat variable. In the majority of specimens the surface of the plates deu.sely covered with somewhat irregular, very fine, closely arranged, longitudinal and transverse striaj ; the longitudinal ones running in almo.st parallel lines from the upper edges of the radials to the foot of the basals ; the tranHver.se ones, wiiich are restricted to the lateral margins of the radials, traverse the sutures, and meet the longitudinal ones at an angle ; the successive angles, ns they follow tlie plates, forming an oblique line from the top of the radials to their lower angles. In other specimens the striie are broken up into rows of sin til nodes, some of which arc round, but most of them elongate, giving to the surface a peculiar rugose appearance. Sutures not grooved, and often dilHcult to see.

Basals spreading horizontally, forming a flat, sharply pentangular disk; the column facet surroimded by a small, circular riilge, and the space within slightly excavated; the axial canal rather large and pentagonal. Radials hexagonal ; greatest width to length as seven to four, rapidly spreading to two thirds their height, the upper faces al nost straight, being but very slightly indented for the reception of the -jnls; the sloping upper faces forming a deep notch with corresponding f\ic.. of a<ljoining jdates. Costals extremely small even for the genus, trigonal, a little wider than long. Distichals two, quite unlike in form and size; the first rather large and sub- lunate, one of its sides abutting against the costals and meeting above with

Ala

732

lilK ( lUNOIDKA CAMKRATA OK NORTH AMKRICA

its fullosv of tlio Miuiio ray, tlio opiuwito side iigiiinst tlio liirgu intorrndiiil jiliitu, the lower face rostiiij^ miDii llie ni(1iul«. Tlio Meeoml ilisticluvl trigonitl, very small, not larger timii the costals, the two of the Mamo rny together I'oniiiiig a triangle, from the sloiiing .sides of which the arms are given off, tho lower arm plates resting partly upon the distichalM. Arms two to tho ray, divergent, rapidly tapering at the base, and rather slender ahove ; they aro liisirial from their origin, and the proximal row ol' arm plates takes part in the oalyx. First jdato of the interradial series very largo, its lower portion constituting a part of the dorsal cup, the uitpor part cntorijig into the ventral disk; it hends abruptly inward at two thirds its height, forming a sharp edge along the margin. The lower end of tho plate deeply wedged in lietween the radials, the middle portion resting against the sides of tho distichals, tho inllectod upper end against the covering plates of the ombu. lacra. This plate at the four regular sides is followed by two rows of inter- andndacral plates, generally arranged three and two, of which tho upper row abuts against the orals. The anal side has from ten to twelve plates of irregular arrangement. Ventral disk depressed hemispheric, the plates tumid, with a small tubercle in the middle. Orals oxcentric atid asymmetrical, the posterior one wider than long, but not larger than the others. Ambu- lacral plates much smaller tiian the surrounding plates; the primary ambu- lacra roofed by three series of plates, the two outer ones consisting of short, transverse piece.s, separated by a few elongate plates. Tho covering pieces of the secondary ambulacra much smaller, and separated by one or two largo intoraxillary pieces ; they are composed of two rows of regularly alter- nating plates. Anus almost central. Column round, so far as observed; the axial canal pentogonal.

Ifiiri-MH ami Loralihj. — Niagara group ; Decatur and Wayno Cos., Tenn.

2'iJiH's in the Mineralogical Museum at Breslau, Germany.

*

Marsupiocrinus striatus w. nnd .Si-. (nov, spec,). Plate LXXV. Figs. 17, 18.

A little larger than the preceding species, sometimes attaining a width of G cm. Calyx twice as wide as high, height of the dorsal cup about equal to that of the disk. Dorsal cup truncated to near the middle of tho radials, then abruptly spreading upwards, the upper end .slightly curving inward. Plates densely covered by fine stria) passing from the radial facets out to the

^

'* 1

I'LATYCHIMI)/K.

733

T

<if

w

intcrrndiiu nml IjiiNi-radiiil xutiircN, mihI iVdin llio lait( r to tlio column. Siituru line's faintly gioovi'd, except tlic intoibaHiil onen, wliicli aio obHolctc. Ventral dixk low lieiiiiNfiiierical, the platen convex.

Uasal ili^k a little concaNe, large, decagonal in outline, the faces meeting the radials being more or less dislinelly angidar. Column facet small, cir- cular, slightly excavated, and surrounded by a faint ridge ; the a.sial canal largo and ob.tcurely pentagonal. Itadials at their widest place twice as wi<lo ns long. C'ostals extremely small. Disticlials large, their outer lateral faces longer than those meeting the costals, their lower faces resting upon tiie rndialM. Intcrrrdial plate largo, placed vertically; tho extreme upper end slightly incurving; its lower faces rest between two of the radials, the lateral ones between the second costals, and the three upper support three intcram- bulacrals, which are followed by two others in the next row, and these liy the orals. Orals quite asymmetrical and small. Ambulacra exposed at the di.sk, tho covering pieces very regularly arranged; composed of rather short, transverse pieces alternately disposed.

I/iiraon mid L<icallt>/. — Niagara group; Decatur Co., West. Tennessee.

Ti/ppK in the collection of Wachsniuth and Springer.

Iii:)n(trks. — This species dilTera from M. /onicsansis in the very much larger basal disk, which in this species is generally decagonal. The differ- euces in the ventral di.^k are also quite marked, the ambulacral plates especially being much larger.

Marsupiocrinus tentaculatus * (Ham.). Piute LXXV. luijs. 19a, h.

1S,)S. rinh/miiiisleiil,ii-iihitii' — \\ku.; I'lilininl. N. Yiirii, Vul. III., p. 110, Plntc 5, Figs. 1-4. \is\. Mdrsii/ii'ii-ri/iim Inildi'iiluliia — \V. iiiul Se. ; Kcvisicni, I'art II., p.. li.') (I'rocccil. Aciul. Nat. .Sci. J'hila., p. 2;ty).

A much smaller species than the preceding one, and having twice as many arms. Dorsal cup short, bowl-shaped, slightly lobcd at the top. Surface of plates ornamented by radiating ridges, of which seven or eight proceed from the lower edge of the costals to tho basi-radial and interradial sutures, and to the basals, where they end in a circular rim surrounding the column facet.

* The specific name has refcrcut'c to tlio large piiiimlis, wliii-h by some of tie earlier writers were culled tentacles.

;3i

IIIK » IIINUIDIIA lAMI.ll.Vi.V Ol' NolMIl AMKIJU A.

MumiiIh hIioiI, the .tuim(.'H vliiMo. Itiidiiils mil i|iiii«' iih w'uU- um loii;;, Iiox* aiiguliir; tlu' ii|>|i('r liicu I'ur tlit- I'cci'iilioii of llio cu^italM and iliMticliiilN u littlu coitcuvu; tliu Mlu|iiti^ ii]i|)i>r Iucoh t'oniiing ii dui-p iiutcli for the ro I'litioii ol' a htrgi* inU'i'lirachiul phile. CuntalH iiiudui'ati'l^y lai'gu lur thu guiiim, trigunal, wiiU'r (liaii high. DiNtiehals a little laiyer than the euitajn ; |)eiitag<>iial and iixilhuy. Tliey re«t with their lower laeen npon the radialw, and with ono of their hiteral onus against each other, with the o|i|io.«ile one against a large interhrachial, wliicli rineH to tho top of thu firnt arm plate, incorporating this with the calvv. Ann-* four to the rav ; thu five or six proximal arm platen wedge-form, nnd arrunged in a ningle Herien; tho wncceeding onen gradually changing from cuneatu to pentangular, and dinpoHod in tworowH; the niir- fnco of thu platcH itomewhut convex and thickened in the direction of the piiinuluM. Pinnules heavy, composed of long joints, Ihiekeiied at the ex- tremities, and slightly constricted along the niiildle. The proximal j)ininilo of tiie two inner arms of tho ray is given oil' from the inner wide, that of tho two outer arms from tho outer nido of the ray. JStructuro of ventral disk unknown.

JliirUuii awl Localili/. — Lower Ilelderberg group ; Schoharie, New York.

f (■

('.') MarsupioorinuB priematiiruB (IFm.i. nmi Wmn.). rinte LXXIJ. Fi,js. J la, b.

Is'r). riatiii'i-iiimi pMimitiirim—WKl.l. niiil WiilTKlKl.D! (ioiil Suiv. Oliiii, Vul. Tl., p. 12t, Plntn n,

I'itfs. ;i 1.1 ft.

1835. Miir.viiiiiii'riiiu.1 iiriniiiiliirui — W. iiiiil Si'. ; Itc'visiciu, I'nrt III., p. Uj (I'luri'id. Ai'.'id. Nut. .'*i'i. I'hila., p. 337).

Of medium si/e, Dorsal cup not as high a.s wide, strongly qiiinqudohate in a dor.sal aspect, owing to the thicki'ued, tumid character of the radials, which form the widest part of tho calyx; the sides of the cup rapidly contracting to both end.s. Plates heavy and strongly convex ; tho surface smooth.

Basals moderately large, constituting only a small proportion of the height of the dorsal cup ; their centres tumid, and projecting downward in the form of throe strong, rounded nodes; tho inner portion of the plates, which form.s the columnar attachment, deeply concave. The interbasal sutures distinctly grooved. Kadials largo, more than once and a half as wide as long, the facet for the reception of tho costals and distichals somewhat indented,

..

I'LATYCRtNID.T;.

7;irj

tho oiitor mill to tlio Man of (lii' liicotM Hlijflitly triinniU'd by fl" (liHt inter- rniliiil pliitt', wliich in xtriclly inlorljiiu'liiul, r'\»'u\if only to tliii top of ilio (liMt ilinticlmlH. Co-tiils Hniiill, ns lonj^ iim « idc, trigonal, tlio niilcM convex; tlicy occupy II tliiril of llic riuiiai lacetM, tiio (itlicr two tiiirtls licing occiipicil l<y tlio iliAticlialM, DisticiialH two; tho Ih-Nt a little larger tluin tliu coxtaN. thoHO of llio Maine riiy mt't'tiii;^ aliovo tlio latter. Secoml diHticlials fiil)- f|iiaili'aiignliir. Kcparuleil fioin the CwM liy a deep groove ; their outer eclgew distinctly excavated at tho upper end, I'orining ii well deliiied. .-(emieircular fncot for tho ruocption of tho nriiiH, which llico nearly hori/ontiil. Second diHtichals He[)arated interradially hy two very Hiiiall interlirachial plates. Anns two to the ray; their Htriictiire and that of tlu' ventral disk unknown.

Jftiii-.'iti mill I.iiiiili/i/. — Niagara group; near (Jrecnville, I)arko (>'o., and at Cedarvillo, Ciroonc Co., Ohio.

7Jy/'c in tho collection of Hev. H. Ilert/.er of Herea, Ohio.

li'iiiiiir/,s. — The description and (Igiiro w 'ro made hy Hull from n giittn percha impression of n natural mould in the rock. The specimen ligurcd on I'iate I,XX\'., Fig. 11, may represent a Mursiiphicriiiiia, hut is more prohahly, wc? tliiiik, a Citliivcriniis. It was found in the Niayiira at Miujuo- keta, Iowa.

CORDYLOCRINUS \sut..

]S7S. Am.kiin; liviiiciiir. CiiiMiidcnniiii Sin'ciii', |i, It.

1S*9. ZiTTH.; Iliiiiilli, .111- I'lilii Iiilnuii., v.. I. I., p. lilV>.

ISSl. W. nrul 8p. ; ltivi»iiin, I'lirt II.. p. «() (I'l^ccnl. .Vcnil, Nal. Sci. riiiln., p. illl).

8jn. I'liilneriiim (ill piiil) — I'liii.i.irs; MiuchiKoii's Siliiriii, iA nl., I'liili' 1 1, I'ii;. 9.

Angolin defines this genus ns follows: " Basalia tria, eonnatn. Radialia primaria porniaxinm. cetera magnitudine mnltoties snperantia ; ."ccimdaria et tertiaria transversa. Interrailialia in trihus verticillis. Brachia ([iiin- (|iio hidigitata, pinniiliv longissimie." lie places tho genus niidor the Platycrinidic, and refers (o it a single species from flotland, of which he gives a ligiiro. This s])oci(>s Ims close nfTmities with the three Aiiier- ican species which TIall ( Palo'ontolojry New York, Vol. II., pp. 11.'! to 110) described as P/nfi/rriiuis ji^innofnia, I', piirnin, and P. riiiiiii/iisii)<. The latter nndouhtedly are generically identical with a small form from tho Wenlock group of Dudley, known nnder the name of P/nti/rriinin retlnriiis Phill.. and with two other iindescrihed species which also occur in the neighborhood of Dudley : one with four arms to the ray, the other

73G

IIIK CHINOIDKA CAMKHATA OK NOUIJI A:^IKIiI('A.

Hr

somowlmt larger, wiUi only two arms like " J*hit;/rrliiiis " rtt!<irii(s, but these beautifully sculiHureil. All those species, iiieUuliiig Conli/lovriiiHs cam- tiii>, agree in the basala and ratlials witli I'M;/cn'iiiis, but have two costals instead of one, and their arms are uniserial as in the young Pluti/criims, (heir ])innules large and not in eontact laterally. The only point of doubt, and upon which possibly a generic separation from the Gotland form might be justilied, is tiiat the American and Dudley specimens h"ve whorls of cirri (Vom all their nodal joints, which arc not indicated in the Swedish (Wdi/h- rriiin.i roin/iis. However, cirri may have been represented also in that species, and until their absence is satisfactorily proved, we must refer oil the above forms to that genus. The interradial plates, which Angelin dcsciibed as distributed in three scries, in all those species form a part of the disk, only the lower one resting between the brachials. Hall describes a " probos- cis" in •• Pliifi/crinus" j)Iiimosiis, which is imperfectly shown in the specimen, and it is po.ssible that the other species have a similar structure. We propose the following generic diagnosis: —

Basals and radials as in P/n/i/criiiits. Costals two, narrow, attached to a small facet. Arms from two to four to the ray. When four, the last bifur- cation takes place from the si.xth, or as high .is the ninth disticlml. Tin- arms are long and uniserial ; composed either of wedge-form plates alter- nately arranged, or of quadrangular, transverse pieces. Pinnules stout and long, not in contact. The first interradial plates resting against the costals. Column round, with numcrovis internodal joints, and cirrus-bearing. The cirri very long, directed npward, the upper ones rising to almost half the height of the crown, and arranged in whorls of three to four to the arm joint.

DLstrifiKtidii. — This genus is restricted to the Wenlock group in England and Sweden, and to the lTi)per Helderberg in America.

Tijpc of the genus : Curdz/kcriiius covitus Angl.

P

rLATYClJIMD.i;.

Cordylocrinus plumosus (I I am).

riak Lxxv. rill. JO.

1839. IV.ili/rriiiHS iiliimnsi,^ — \\s\.\,; I'.ilicml. Ni'w Y«d, V.il. 111., |>. 1 Hi, l'l;ilc I. V\'f». 1 to 5.

18S1, Cur,/i/liiiriiiii.i iiliiuimii.i — \V. ami Si'.; Ki'visioii, I'.ul 11., p. lio (I'lnir.il. ,\ciiil. Niil. Sri. I'liilii,,

p.a.'U).

Sj-n. I'/ii/j/rriiiiit /uirnii — n.\u,; i'aliiMiiil. Ni'W York, Vol. 111., p. 1 U, I'liilc !■, l''ii;s. (1 to I). Sjn. Con/i/lofriiiiis /iiirriis — W. ami Siv ; Ki-vi^inii, I'ait 11., |i. (ill.

A ^!^i^ll spccios. Dorsal (,".ii) suhpoiitiinj^uliii', oxpiiiuliiij;- ti) tlio iirni biiso.s ; surfiico of platos lliioly j^nimiliitt'il. IJii.^iil.-* wvy thin, widor tliiiii long, the coluinn fiu'ot .smiill. l\;uliiil.s o.xoiivaltMl l\ir tlio rocoption of tlio oos(m1.><. Till) tlirco radiul.s nu'etiuj; 'iii iiiU'Hia.xal .•^iituro di.stiiu'tly anj;ular at tlio lowor oiid, tlio (wo otlior.s no'irly stinij^'lil. TliO upper Du'os of ilioso udjoiuiiig tlie anal .sido I'orniing a deep notch, occupied \>\ a larjie penlaii- fi;ular ])lato, wiiich is succeeded oy a snuiller plate forming the base of a probo-icidifonn tulu' (Hall, I'late I, Kig, .'I). Costals two. Aims two to the ray, c()in|)0.seil of transverse, slightly wedge-form pieces, giving oil" largo pimiules, which are not in contact laterally. Column composed of nodal and iiiternodal joints, the latter rapidly increasing in number, the nodal joints giving off whorls of cirri, one to each side, interradially arranged. The cirri are formed of short pieces; they are liliform and dirceted upwards, often so long that the tips of the proximal ones pa.ss up to the top of the arms.

IfiirlzDii (iihI Ltwdli/i/. — Tiower Ilelderbcrg group; Schoharie, TIerkimor Co., N. Y.

l{<iiiiirh. — We have not examined Hall's types, but doubt if they show much more of the structure. Tiio form whicii Hall descrilicd as J'laf^rrliiiis jiiirvits is in our opinion a yomiger form of Cordi/hcrlnux pliimmtus.

i

t'

(.') Cordylocrinus ramulosus (II.m.i.).*

1S.')S. rUiliifrinm nimii .«■«.«— ll.u.l,; rala'iinl. New Yiirk, V,,l. HI., |, 1 1.",, I'lalc I, b'iu"^. 10 In I.'!. 1?>SI. Cofihfl"\'riiinn ri.iiiiilv^iis — \V. ami Sr. ; Kcvisioii, Tarl II., p. (10 (Pritci'fil. .\ratl. Nal. Sci. IMiila.,

p. 2;u).

Dorsal cup small. Hasals wider tlian long. Hadials comparative!}' large, wider th;ui long, very {)rominent below tlie facets, and contracted toward the upper lateral angles. Costals two, very smidl. Arm.s bifurcating from

• This .species nwy lieloiii; l.i a w\s (liiri'irnl !;nmp. 11 was iipp;\ri'iilly deserilicil IVcini vciv iiiipi'rfecl specimens, ami luil liavini,' .seen the types, we yive Hall's (lese:ipliiiu wiih our teruiimilogy.

93

U

7jS

TIIK CniXOIDEA CAMKRATA OF XORTII AMERICA.

the second costals, and again from tlie tenth distichal. Ann joints wider than lony, rounded on the back, and with strong pinnules composed of joints a little longer than wide. Column round, rather large, the joints growing thicker downward. Cirri have not been observed.

Iloraon and LucaUty. — Upper Ilelderberg group ; Schoharie, Herkimer Co., N. Y.

I

COCCOCRINUS Mi'LLEu.

1855. JoTr. MClleiii Vcrli. Naturliist. Vcroiii Uhcinliindc, Vol. XII., p. 20.

18,57. ricTKr; Triiilo do P.iluoiit., Viil. IV., p. 310, I'liilo 100, I'ig. 3.

ISrtO. F. lloEMKU; Fuss. I'liuna West. Tennessee, p. 51.

lSfi2. DiM.vitnix mill IIii'B! Hist. Niitiir. des Zocjphylcs, p. 107.

1S70. ZiTTKi, J llaiidl). dor I'aliuoiit., Vol. 1., p. 3t7.

ISSl. \V. and Si'., Revision, Part II., )). 58 (I'meeed. Aead. Nat. Sci. Pliiln., p. 232).

18U. P. llKitB. Caium;xtkii; CliallenijiM- Kep. ol'tlic Stalked Crinoids, pp, 160 to lfi3.

13S5. \V. and Se.; Revision, Part HI., p. Ill (Proceed. Acad. Nat. Sci. I'bila., p. 336).

1887. W. and Si>. ; Proceed. Acad. Nat. Sci. I'liila., p. 22.

18S',). Neim.wr; Stiininic des Tliicrreiches, p. 170.

1890. S. A. Miller; North Anier. Geol. and I'alniont., p. 232.

S.yn. Phili/criiius (in part) Roemeh; Rheia. Ucberganijsiiel)., p. 63, Plate 3, Fig. 3.

Ci)rcorriiins U the simplest po.sfiiblo form of the Camorata, the calyx consisting only of tiiree basals, five radials, two costals, five small inter- briichitils and five orals. As in Pliit//cr!ni(s, two of the basals are larger and equal, and the third, which is but half the size of the others, has the same orientation as in that genus. The radials arc large, as in all Platycrinida3, and excavated at the upper end to form a facet for the reception of the costals, which consist of two short, transverse pl.".tes (not of one as here- tofore supposed). The upper costal is axillary, and supports two arms, which apparenth' were delicate. The interhr.achials rest at all sides upon the trimcated upper angles of the radials. and against both costals. The ventral disk is covered entirely by five large orals which slightly touch the radials ; thej' meet in the centre, but are parted on approaching the arm bases, where they leave narrow slits, at the bottom of which sin.ill portions of the di.sk ambulacra make their appearance; while they are at the upper end altogether subtcgminal. The lower margin of the posterior oral, and the upper of the intorbrachial plate below, are deeply excavated, and form a large, circidar anal opening. Column round.

Distrihutlon. — Two species have been described, one from the Niagara group of Western Tennessee, the other from the Middle Devonian of the Eifel, Germany.

PLATYCRIXID.E.

iO\)

-I

T//pc of the genus : Coccoen'niis rosaccm (Roemor).

Remarks. — Coccocrinm has close affinities witli Cidhcncriiim Miillor. closer even than has been generally supposed. The former was described by Jliiller as having only one costal, while he recognized two in the latter, and made this the principal distinction between the two genera. Specimens iu our collection show conclusively that not only C hacca, but also C. rosacms, has two costals. The only difference in the calyx upon which a generic separation might be upheld, is that in Culkocrhms the disk ambulacra are completely subtegminal, while those of Cuccocrinus are partly exposed. The disk ambulacra, which are indicated in our specimen of C. rosaccus, are very narrow, and composed of minute alternating pieces, but too small to bo satisfactorily represented in our figure 14 on Plate III.

Coccocrinus bacca Kokmek. Plate LXXV. Fig. 15.

1800. F. RoEMEii; Silur. F:iiiim dcs Wcsll. Toiin., p. 51, riafo t, Fif;s. ha. b, c. 18S1. W. ami Sp. ; Ucvisiou, Part II., p. CO (I'locceil. Aciul. Nat, Sci. Pliil'a.,'p. 234).

A small species. Dorsal cup bowl-shaped, wider than high, subpentan- gular from a basal aspect, and somewhat a.symmetrical in its general form. Plates smooth ; the suture lines not grooved and frequently invisible.

Basals large, forming a low, rounded, pentangular basin, provided with a small, circular facet for the reception of the column. Radials a little wider than long, the sides nearly parallel, the median portions slightly curved longitudinally and projecting outward. Three of the radials of similar form and symmetrical, the two posterior ones of irregular otitline : the limbs toward the anal side rising considerably above the level of those of the opposite side; radial facets occupying two thirds the width of the plates. Costals two, very short ; the upper one axillary with obtuse upper angle. The interbracliial pieces as large as the two costals together ; their lower ends resting within a small notch formed by the radials, the sides against both costals, and against tl,e ambulacra, the truncated upper face against the orals. Four of the plates are equal and stand at the same level, their upper ends inflected ; the posterior one is erect and elevated above the others. Anus excentric, at the top of the posterior interbrachial, which at its upper end bends longitudinally inward so that its sides meet and form a small tube. The orals unknown.

i'W

HO

THE CRINUIDEA CAMEBATA OF NOKTII AMERICA.

IlurUon and LucaVitij. — Niiigara group ; Perry Co., Tenn.

Ti/iii's in the Minenilogiciil Museum at Breslau, Germany.

liemurks. — liocnwvA figures are misleading. The calyx is not symmet- rical, as he represented it, and the interbrachial pieces bend but slightly inward, even at the lour regular sides. Neither do we find the small plates at their sides, nor the linear luibulacral .slits; the spaces between the upper ends of the intcrbracliial plates are occupied by several small pieces, whicii are probably covering plates of the ambulacra. He also fails to represent the costals; they are plainly seen in two of the four specimens in our collec- tion occupying the part which in Roemer's figure appears as if constituting a projection of the radials.

.A,

HEXACRINID.E W. and Sp.

jrONOCYCLIC. RaDIALS IN CONTACT EXrKI'T AT THE POSTEniOR SIPE, WHERE TllEV ARE SKrAKATED 1)Y AN ANAL PLATE. BasaLH I'ORMLNO A HEXAGON. StBUCTUHE OTHER- WISE A.S IN THE rLATYtltINII)-E.

Amiti/si's oft/ii! Genera,

A. Basai.s 3.

1. C'ostdl.f 1 or 2.

Arms ill furiii of iii.iin trunks giving off liiti'ral branches; uiii-

scrial Ifcxncriniis.

Arms branching, biserial. I'kitos of tlie caly-\, and some

of the free bracliials, covered with movable spines . Arflinicunthit.

B. Basals 2.

1. Custiih 2,J'iriii!iii/ " si/-:i/ffi/.

riates tliin, cobiiiin nmiid Di-linrrlnus,

Column crcsccnt-shaiii'd, giving olT two rows of long cirri . . CmiijifucriiiKS.

2, Cosfdh 1 ; fr!;/oiial, riri/ miiu//, snnniimeK h'nhh'n hij the dist'ifliiils,

ir'itli jirst ji(i/m<irs titHrliiinj the railliih ; (irniK hiserlnl. Plates thirk ; anal plate in form and size resembling the

anterior radial Tulurocriiuis.

Anal plate much smaller than tlie radials; radial dome plates

produced into wing-like appendages Ptcrotncriiins.

I

.Sfei'-~":

!

1V2

THE CRIXOIDKA CAJIKRATA OF NORTH AMERICA.

Geoluijkiit «ni! fii'oi/rdjihlnil DUtribution,

Number of known species. (Open figures iudii'iiti' Anifrii'iiu j IIkisu iiuuknl (), Europenn).

VnHMATloV.

IIKXAIIIIMI.V;.

American.

Si en

.1 9 S

3

.s

'Ih

1

s c X

1

a.

en

B

•c

3

5

1 1

3

1 1

u c

Ivuskaslcia.

3

1

8

St. Louis.

1

1

c

Warsaw.

(>

Keokuk.

C 1^.

ii

1

I'liper Hurlington.

7

Lower liurliugton.

Kiiulci'liook

;}

'S e

1

Chemung.

O

Hamilton.

Holgiuni.

2(.S)

1

Upper Helilerberg.

Eifcl. (21)

Total species .... 85 - /..T,.,

2 1 ,'5

.so

0-')

2

7

8

jv

IIEXACiaXIIKE.

748

Fig. 2i.

i

Fi!,'. 20. Ti^. 21,

i = b:isiil5; /< . = railials ; .(' = siieciiit niiiil pl.itu ; •' = syzygy.

Remarl-s. — Tlie Hcxncrinidii) are closely allied in general strnctnro niul habitns to the Pliitycriniihi", but arc at f>nce distinguished, a.s already pointed out in the remarks upon that family, b- having a largo anal plate between the two posterior radials, and a hexagonal base, the basals thus supportiiii.- six plates, instead of live. The base of the IIcxacrinid.T may be composed either of three plates, or only two ; but in either case the plates are suli- stantially equal, and form a cup with six salient angles, and cither two or three re-entering angles at the upper margin. ^Yhen the base is bipar- tite, the suture runs from the anal plate to the anterior radial ; but when it is tripartite, the sutures are directed to the anal plate and the right and Id't antero-lateral radials. In either case, therefore, there is always an interbasal suture running to the middle of the anal side, whereas in the Platycrinida> tlie nearest interba.sal suture to the anal side runs to the middle of the right posterior radial.

The genera which we refer to the Tlexacrinidaj were always placed among the Platycrinida> until we separated the two families,* and fm-ther investigation only confirms the validity of their separation. It is based on a fundamental structural modification, for which we find an exact; parallel

* Revision, Piirt III., p. 93.

1

744

TIIK CHINOIDKA CA.MKUATA UK MtUTll A.MKUKA.

At

ill lilt' topical section of tiiu C'liiiii'riitii l)C't\veen the MelocriiiiiUu anil IJnto- ciiiiidii'. Ill both cases tlic group witii iR'iilagoim! Ikim.-, ami in which tho anal is iinreprescntcil, is tlio earliest in gcolojjical sei|Uonco.

The llexacrini(la) have not been discovereil in any I'oiniation oliler than the Devonian; but there they occur abundantly- in the Kii'cl liniestoiies, from wliicli twenty-four species have been described. Tiny iiiiiye through the different divisions of the .Siibcarboiiiferous, and are leiireseiited in the last niombcrof that system, the Kaskaskia group, by twelve species. ISeyond that they are not known ; but we shall not be surprised to hear of a Ile.xa- crinoid being found in the Carboniferous.

Tiic Ilexacrinidtc arc the only Camerata in which the arms are uiiiseiial throughout the Devonian ; they gradually become biseii;il in the Subcarlio- niforous, in the lower part of which all gradations, from uniseriiil to strictly bLserial, are found together in the same genus.

The family consists of six genera and eighty-five species: fifty -two from America, and thirty-three from Europe.

HEXACRINUS Ai stiv.

ISm. AisTIN", Mdiiiisr. Hcc. iiml t'ciss. C'liimiils, p. IS.

IS.Vi. Hi.Ku.visc K iiM.I Li; IImn ; K.cliri-. Crin. Ciiili. IMy. p. IGO.

ISj.'i. !•'. KiiKMKii; Lcthii':! drill,'. (Aiim;. H). p. iH.

Isjr. Jim. .MCli.kk; X<'iii' Kcliinciil. I')ill. Knlk,, p. 217.

lS,-,7. I'lCTKT; Tniili' (!.■ l';ilninl., V(.l. IV., p. lilii.

1862. DujAiuns .mil llrrt;; lli>l. nalur. dcs /diiplivlcs F.cMikhI., ]i. l,j.j.

Isfl7. Stiii-|.TZKi .\1 fir. EchiiMid. hill. Kiilk., p. 71.

1S79. M'. mill Sp, ; I'lcic'ciil. Aciiil. N;il. Sci. I'liila., p. 232.

IsSl. M'. mill Si'.; Ucvision I'iilivnor., It., p. 7!'-

ISSl. \V. mill Si'.; Ui-vi.^oM I'alii'ud-.. HI., p. llCi (l'r.ici'i-,1. Ar.iil. N.'il. Sri. I'iiilii., p. :!:i-),

Svii. /'/((///.■/•///».>— I'lm.i.ii'.s, ISIl (niil \^'M)\ I'lilu'iiz. I'n^--. Ciinnv., p. Js.

Svii. I'/ii/i/critiiix — (iiii.ntrss (iii p,irl)l IS'tS, Novii Act.i .\c. Lnipniil. .MX., p. lil'i.

Svii. J'/ii/i/rniian — .Viiv.s.siz (in purl); IS.'i.j, .Mnii. Sue. Xi'iiciiiil. 1., p. \\)7.

SvM. /V(//y/v;//«.t — AisTix (in purl); 1S12, .\ini. mul .\l;if,'. Niil. Hist., Vol. X., p. lU'.t.

Syii. Pliili/criiiiin — C. K. ItoEMKIi ; l**!;!, Vi'rsli'iii di'S lIiirzijohirRi's, p. 9.

Syii. I'liili/rrifiim — V. A. Uii:;MKll; l^U, liliiinisli. Ui'lirrffiiiftsiicliiri;!', p. fiH.

Syii. I'liiti/rriiiKH — F. .\. lioi.Mi:i<; l'^.Vl, Verlimiill. ii:itiirli. Vrrriii'i I'. Hlii'iiihiuln. p. W'i.

Syii. Phil;in-iiiiiS'-'\.'«^'i; ISdO, Trmis Aini-r. I'liilos. S.ir, Vnl .Mil , p. l.V.).

The dorsal cup composed ahiiost exclusively of basals and radials ; the latter enclosing a large anal jilate. The basals consist of three sube(|ual pieces, forming together a rather large, more or less deep cup or basin, hexagonal in outline. Radials large, subquadrangular; their superior faces excavated so as to form a facet for the reception of the costals; the limbs slightly truncated to receive the fir.-it row of interradials. The intervening

'*ffl>^,ff''tl

IIKXACRINID.K.

745

Jl

nnul pliito \h generally of the Kttine wi/e nn tiie rndiiil-*, but obtusely angular at the loner face, and broadly truncate at the upper. Costaln one or two ; very small, in most cases not filling the whole width of the fucct. When two costals are represented, the plates are closely united, and form a sy/ygy. Anns, so far as known, consisting of ten stout main trunks, witii armlets froM) one or botii sides at intervals. Main arms us well as arndets composed of quadrangular, single joints, and the plates of bolh pinnule-liearing, except the nxillary ones. The piiniules are given off, so far ns observed, from one side of the arms only, not alternately from opposite sides.

Tiie first iiiterradial row of plates consists of one or three pieces, wliieli are in contact with the lower bracdiials, and occupy the peripheral portions of the caly.x. They are followed by inter-ambulaerals which enclose the orals. Ventral disk from low-convex to hemispherical ; the plates more or less nodose. Orals generally well defined ; the posterior one largest, almost central, and pushed in between the other four. The plates covering the food-grooves consist either of a few largo plates, or of two rows of small pieces, alternately arranged.

Column roinid ; axial canal small and circular.

DisfrifiiiHon. — Ilcairriiins is restricted to the Devonian. From America only two species are known, both from the Hamilton group, and of these but one or two specimens have been obtained; while in Europe the genus is represented by many species, r>nd specimens are quite abundant.

7}/pe of the genus: Hr.vucrimis )nd<i Austin.

lliniarhs. — It is wortiiy of note that the two American species of Ihxa- crhvis have two costals. while the European, ,so far as known without excep- tion, have but one. They agree, however, in other respects so closely that ■we doubt the propriety of making this a generic distinction, especially as the two plates obviously form a sy/.ygy, and take the place of one.

Hezaoriaus occidentalis w. and Sp. (nov. spec). PhUe LXXriII. F!</. 10.

A small .species. Dor.sal cup higher than wide, broadly truncate at the base, very gradually spreading to the arm bases; the sides a little convex; the plates moderately thick and without ornamentation ; the suture lines iudistiuct.

04

t

710

TlIK CUIXOIDKA CAMKUATA OK NOHTII AMKUIt'A.

I \,

Bawil Clip projecting latonilly in lonii of n rim ; its lower fiiue xliglitly cxciiviited fur the reception of ii large r*teiii. liaiiialH about one third longer than wide, n little wider at tlie top tiian at the bottom; I'aeetn for the recep- tion of the costals about two-thirds the width of the plates; wemieircidar, and somewhat thiekcned at the lower margin ; tiie limits hut slightly trmi- eated. Costals two, forming a nynygy, the lines of union obscure ; the liypozygal joints very short and siibquadrangular, the epizygal, of which the lower part in placed within the facet, considerably longer and pentangular. Arms ten; stout, cylindrical, composed throughout of rather long, single joints, of which the upper and lower faces arc parallel; the nuiin trunks giving ofl' arndets, one from each fifth or sixth joint, the intervening joints pinnule-bearing. The armlets extend to the same height as the main arms, but have only half their width, Hoth are composed of quadrangular joints, which are somewhat shorter than wide ; while the pinnules arc short, and their joints fully twice as long as wide. Arndets anil piiuiules are borne only on one side of the arms : in the anterior ray from the inner side, in the lateral rays from tlu" outer one. There is but one intcrbraehial plate, but tliifj was apparently followed by several rows of small, nodose, interambu- lacral pieces. Form and position of anus uid^nown. Column round; the nodal joints considerably widest, and distinctly rounded at their edges.

llarizoH and Londify. — Hamilton group, near Davenport, Iowa.

Ti//)c in the Museum of the Davenport Academy of Natural Sciences.

Jii'mfir/t's. — This species is peculiar for its arm structure, but still more for the arrangement of the pinnules. In the latter point it approaches AndiHuhtcrlnun cajmni/ontiis ; but while in that species the position of the pinnules changes from one side to the other after each bifurcation, in this they are apparently given off from the same side throughout the full length of the arm.

Hexacrinus Leai (Lvon).

Plafe LXXVIII. Figs. 12a, h.

ISOO. rh>;/i-niim leni — '[Ann; Trans Amnr. Pliil. Snc. riiiln,, Vol. XIII., p. 159, Tlutc 2t, Vign.ff.ff/. ISHl. Ilejtiii-rinii^ L'lii — W. .anil Si'.; Hcvisiuii PiilH'oor., rail II., p. SO. 13S9. Vliilgrriiitts Leai — S. A. Miller; X. .\iiicr. CIimjI. luiil I'lilivont., (i. i'i\.

Of moderately large size. Dorsal side of the calyx .semi-ovate ; plates thin and without ornamentation ; the suture lines not grooved and rather obscure.

I

(«<'■'

IIKXACHIMI)-K.

747

nuHiil Clip largo, broadly oltcoiiii'iil, its licighl aI)oiit tliioo oiglitiiH ilio loiiglh of tho calyx to tlio aniin, itx lower eiid slightly itroji'ding mul Irim- cated, tho trimcatt'd part coinpletcly occupied by tl'o largo ii])pcr Htoiii joint. Radialn gradually spreading, their upper faces nearly one-third wider than tho lower, and e(|iial to the length of tho pliitos ; the lower faces in three of tho plat(!H a little convex, in tho two meeting the interlmsal sutures slightly angular J facets deep, soniicircniar. Tho outer surface of tho radials iw marked hy a median ridge, rather faint at tho lower end, but growing wider and (piit(< prominent \ipward. Costals two. short, twice as wide as long, rounded on tho back. Of tho disticlmls only two single plates are preserved ; thoy nro as wide an, but shorter than, tho costals, and are connected laterally. All other parts wanting in the two typo specimens, with tho exception of a few joints of the stem, which arc round and extremely short. The nodal joints arc very much the wiilcst, their projecting edges exceedingly thin and knifo-Iike ; while tho edges of tho intornodal joints arc rounded.

llirlziiii and LiicaHli/. — Lower part of Hamilton group ; Louisville, Ky.

Tijiic in the collection of tho late Major S. S. L) on.

T

L

ARTHRAOANTHA Wh.mam^.

ISS.I, n, S. Wru.uMs; rrncml. Aiiicr. riiiliis. Sor. (.\|iiil), p. St.

ISSj. W. mill Si', ; Ui'visiciii, I'lilinirr , I'tiit HI., p. 11(1 (I'rocccJ. Acnd. Nr.t. Sci riiiln,, p. 33S).

18S7. WlllTKWH.S; I'ulltr. til Clilllul. I'illn'iillt., Vol. I., p. 1)1).

18S9. S. A. .Mii.i.Ku; N. Aimr. (i.'nl. mul I'lilinml., p. i-a.

Svii. Ili/tlricriiiiif lliNiiKj 1S>>.), Ann. nnil Miij;. Nut, Ilisl., p. I."i3.

Pliitos arranged a.s in JfrKcriniin, but covered with numerous tubercles, each of them having a small pit for the reception of a movable spine. Uasals tlirei, large, suberiual, and pentangular. Eadials and anal plate as in Ifcm- rn'iiiis. Costals two, comparatively large, and forming part of the doival cup. Disticlmls three to four, small, curved like arm plate.s ond directed outward ; those of tho .«anie ray .separated by intoraxillarios or in contoct laterally. Arms ])ranching, bi.><erial ; pinnules of moderate size.

Literradial plates numerous, covered like the plates of the dor.«nl cup, with irregularly arranged, spine-bearing tubercles. Anal opening cxcentric. Column round.

Uix/n'bi(tlon. — Up]ier Devonian, and only found in the neighborhood of Lake Ontario.

Type of the genus : Arthracuntha ithacams Williams.

f

7IH

'illK CltlNtdhDA lA.MKKAT.V »»K NnltTII AMKIMCA.

h

*.

1 s

^

I'liiuirls. — Tlio fdi III imdt'r foiiNidi-intioii wiih difliu'd in 1S8.1 liy WilliiiinM ar* Aif/iriKiriiiit/i'i, Itiil the initiic uiim aricrwaidH rliaiigi'd hy Iliiidf Id //>/n/rlirliiiin, ln'ciiiim' it \vaf<, nn lit' inniiitaiiiod, iiicori'iM'tly foniicd, and II naino tot) Niinilur (o Arlhrnidiilltnn, prcvioiiNly cinplnyod liy Sclnnardn lor II gonns of liolnloiiu. We Imvu IoiiiutIv in I'nit III. of llio Ifcvivion c>xprof<.«iMl till* ()|iinion lliiit nccordiii)^ tu tlio iuIcm of niiincniliiliirc Williuiiih' nnino would liavo to lio lotaiiu'd, nn it was Hiidiilcnily diHtinrt from llio oflipr. even if clinnircil to Arlhrnrnnllnt. 'I'lu* kiiiiic view of tin' vwi^ via* liiki'ii l>y I'lol'i'.i.Hor Wliitriivi'H and .Mr. S. A. Miller, lioth nft'('|itiii;i' Williams' naiiio. li' till" (|iii'stl()n wi'io to Ik- (Iccidi'il hy notno antlioritativo Ijody of nafiirali*l.«, we hIiooIiI vote in fuvor of Kiippro.s.sini,' Art/iriiiinnil/nt and K'gi- tiini/iii^' Iliiide'H name, on the gronnd that no author should he permitted, at lliii day, to e.'^tahliMh a yeniis of ('liimid.s under any name which does not end with the recojinizeil termination — " i-riniis." As it is, we have eon- eluded, thougli with miieh reluctance, to retain the name proposed hy Williams, hut writiiij^ it Aillivunnillid.

Arlhrnniiilliii is closely allied to J/udfriitiis, from which it differs in Iiaviii;;' hiseriiil arms, and niovahlc opines \\\wu the calyx and arms, The spines were jirohahly attached to the plates hy elastic lij^aments, no as to yield when accidentally lirouj^ht in contact with other olijecis ; hut we douht if they represent either functionally or structurally the spines of the Kchini. In this wo dilTer from Williams, who thouj^ht that this structnro cstahlishes a relationship hetweon Crinoids and Perischiechinoidea. He compares them with the spiiie-bearinj,' jdatcs of hrjiidirinlrxx i IJ'il!iiiiii/< Miiller. an<l is led to helieve that these were proliahly plates in the "vault" of a true Ciinoid like Arllimniiilha. We can sec nothinj^ to support this view; the Eifel species is undouhtedly an Echinoid, and the i)lates of the two forms have a superficial rescmhliinco, hut are not homologous. The movalde spines of Art/irfiniiil/iii. in our opinion, represent the sharp point of an ordinary spini- ferous Crinoid plate, united with the hasal portion hy ligament-^, and iis such are of hut little importance in classification. Wo therefore consider the mohility of llie Pi)ines of only generic importance, difiTering therein from Williams nn<l Ilindo, who wore inclined to make ArZ/inminl/ia the type of a distinct family.

/

IIKXACUINII».i:.

740

Artbraoantba ItbaoonRla Wiii.iam*. J'litlv LXXVl. /Vj/.w. 1,1, U,c.

1SS3, VVlM.I*W'>i I'' -mil. AllllT, riiilns. (*nc., p. '<,^. nilll It |iluU'.

J»*5. \V. iiinl .-> •■ I viM.Mi rulir.icr,, I'iUl III, p. II'J

Spt'fimonM rntluT Ic-low nu'diiiiii si'/x'. Calyx oliconifiil. iiinro rnpidly H|ir('ailiii^' . llif liasi-riidiitl mittiic tliaii from tliiTi! vipwanU. Tin' i\^)\xi\\ cup as wide as liigli ; tlio vi'ntnil .lisk Hat. a lilllo (Ii'iuv^-'imI in (hi; iiiiilillo.

\hw\U I'oriiiiii),' a low, olK-onicul cup, wilh six well dcliiiiMl ndiiiil and (liri'c ro-onti-riiig angles ; ilic latter facing the distal eiidn of the inteihasal BiitiuxH. Suture lines faintly ^iroovcd ; the column facet small ami round. Itadials rapiilly Hpreadinj^; their upper faces one third wider than the lower, and aliout eipial to tiio length of the plates; facets somewhat projecting and occupying from one third to one half tho width of the upper faces; the lindis at both sides slightly inflected. Costals two. fidly twice as wide as long; the upper one shari)ly angular above, its ,>*li)iiing upper faces concave. Arms free heyond the Hrst di.-ticlials ; lirandiing. divergent, bifurcating at least twice ; composed of two series of deeply interlocking plates, from which nt both sides are given oil' delicate thread-liUe pinnules. The anal plate has the same form as the antero-lateral radials, all being slightly angular below. Tho arrangement of tho plates in the ventral di.sk is not satisi'actorily shown in the specimens; enough is seen, however, to show that there are live sets of rigid covering pieces above tho food grooves, which branch close to tlu' arn\ bases, each set composed of two rows of plates alternatidy arranged. The covering pieces are formed into rounded ridges, which grow more prom- inent ns they oppronch the arms. The intcrbrachials consist of three plates, followed by several rows of interandjulacral pieces, and these by the orals. The anus is excentric, surrounded by a number of moderately snmll, slightly convex pieces, which form a little rouiuled protuberance near the outer margin of the disk. Calyx and arm plates profu.sely covered with spine- bearing tubercles, of which there are thirty to thirty-five upon each radial, and a proportionate number upon the basals; tho costals apparently have two, the free arm plates and the covering ])ieces one each. The tubercles arc wanting, so far as observed, on the interambulacral plates, except upon the anal side. The tubercles arc of nearly uniform size ; circidar, rounded and narrower at the top, and pitted nt the apex for the reception of tho

750

THE CRINOIDKA CAMKRATA OF NOUTII AMKUICA.

spine. The Mpiiies, which bristle iipwiud unci outward, arc ncieuhir, very limy and slender, varying in length from ten to twelve mm., somewhat thicker near the jiroxinial end, and sligiilly pitted at tlie bottom. Colunni roim<l and coini>aratively thin.

Horizon and Localiii). — Chemung group, Ithaoa division; Ithaca, N. Y.

7//^/(.v in the collection of Prof. Henry S. Williams at Cornell University.

JlciiHirka. — Tiie description was made fi'oin natural moulds formed in the rocU after disintegration of the calcareous test, aud from gutta percha casts therefrom.

X

■^1 !..

I ^

— Arthracantha punctobrachiata Williams.

Plate LXXVI. Figs. 2a, b.

l^S:!. AVii.i.iAMs; Pi'imril. AiiuT. I'liiliis. Sue. (Api-il), pp. S3 nnd S6.

l^^.-). W. :iiiil Sr.; I(l■vi^i^ll, I'alu'ocr., I';iil 111, p. lit).

1SS7. WlIlTKWHS ; Coiilr. to (jiiiiiil. J'liliviinl,, Vdl. I., p. 93, I'liilc 13, Fip;9. 1, Iff.

Svii. I'liili/.riiiiis {'i) /iii,i,/a//ini/iiii/iis Ham. (ligurcil b^' llall 1S7'.', in Bull. 1. N, Y. Slate Museum Nai.'llist.).

Svu. Ili/sliiiriiiiis Oirpriiffri IIlXDK, 18S,5; Ami. niid Mag. Nat. Hist., p. Ifi2, I'latc 4.

Dorsal cup obcoiiical ; more rapidly spreading at the basals than at the iiidials; the latter somewhat inflected at the upper ends. Ventral disk hoiuisphei'ical. Iliittencd in the central ptirt. Pltites witliout ornamentation, but thickly covered by ininute spine-bearing tubercles, which, when well l)fcserved. resemble small cones truncated at the upper end. The sj)ines are elongate, cylindrical, and measure from fifteen to thirty-five mm. in length; they have a short neck at the proximal end, iind taper distally. The distribution and iirriiiigement of the tubercles is quite irregular; they are. a^ a rule, more numerous upon the basals sind rtiditils, but the number varies even among correspomliug phitcs of the same individuid. There arc but \cry few U})on the disticlials and interbr.achials, but they arc crowded idong the median portions of the disk, where, according to Ilinde, they are shorter and comparatively thicker than at the arms.

Ba'^iils large, almost of uniform size; the suture lines indistinct; the lower end truncated to the width of the column. Radials somewhat irregular in form, tlie two facing the anal phite narrower at the lower face than at the upper, iind narrower throughout, the others almost rectangular, and nearly as long as wide. The upper faces are straight, except the median part, which is slightly excavated for the reception of the costals; the outer faces

11

4

IIEXACRIXID.IC.

Tol

angular along tlic meilian line. Costiils two ; llic first niiirow and very sliort; the seconil sharply angular abovo ; its sloi)ing uij^ier I'at'es coiicaM'. Disticlials thiL'o in the calyx; ihosc of the same ray in contact laterally, or separated by an interdistichal. Anns biserial, generally from the first free plate. There arc three interbrnchials to each regular interradius, of uhich the inner one is larger than the two outer, the latter curving outward so as to meet the disticiials. 'Die intcrbrachials are followed by nmnerous rows of small, rigid intcrambulacral pieces, of which the npper ones from each side meet in the summit, there being apparently no orals. 'J'he fnst anal plate is narrower than the radials; it is succeeded by live plates, of which the middle one is larger and somewhat bulging. Anus c.xcentric, placed within a small protuberance. CoUnnn round, formed at its upper end of short joints with sharp, knife-like edges.

Horizon and Localili/. — Hamilton group ; Arcona and Rartlett's Mill, Ontario, Canada.

]ti)H(ir/is. — Dr. G. J. Ilinde described this .species as ILjdrkrhuiK Car/Kii- krl. Wo have heretofore, in Part 111. of the Revision, stated that in our opinion Williams' prior name should bo retained. Williams' description, although merely comparative, is amply surticient for the identification of the species ; this view is also held by Professor Whiteaves and Mr. S. A. Miller.

. 'T

W

L

Arthracantha depressa w. ami Sr. (nov. spec).

Flute LXXVI. Fitjs. 3a, h.

Dorsal cup short, twice as wide as high. Basals so closely anchylosed that the lines of union are rarely seen ; they form a very shallow, hexagonal basin, which near its outer margin is surronided by two indistinct corrugated ridges. A single ridge, oven more obscure, follows the lower margins of the radials, parallel to the basi-radial sutures. Kadials once and a half as wide as long, their lower faces nearly straight, the upper ones to fully one half their width deeply excavated, their outer ends truncated and distinctly sloping. Costals two, on the same plane with the radials, unusually large for the genus, both of them constituting a part of the dorsal cup; they are three times as wide as long, and of a similar form, except that the first is angular below, the second angular above. Of the disticiials only the two lower ones take part in the caly.v ; they are quadrilateral, and twice as wide as the succeeding ones. The free disticiials arc cuneatc to the second or third

51

( f

'•I 'T

(O-

TIIK CRINOIUKA CAMERATA OF NORTH AJIKRICA.

plate, above wliieli the nrnis are biserial and widely divergent. Whether they branch again is not known. There ia but one intcrbraeiiial at the four regular sides, which is located within the dorsal cup; it is wider than long, very large, and extends to the full height of the distichals. The ventral disk is (|uite low, and depres.sed in the central portions, the ambulacra cou- spieuoiisly projecting, especially on approaching the arms. The j)Osterior area is wide, bulging, and composed of a great number of plates, which form a large, rounded protuberance containing the anal opening, which is directed upward and surrounded by very minute pieces. Orals arranged in the usual way ; the posterior one large, its diameter shorter from the anterior to the posterior side. The plates covering the food-grooves rather large ; consisting of two rows of pieces alternately arranged. The sockets for the reception of tlic spiiu's rather irregularly distributed and far apart; they are large and circular, and have a shallow pit at the upper face. The form of the .spines is not known, but they were evidently large.

Horizon and Loailify. — Lower Chemung group ; Steuben Co., N. Y.

J'l/pcs in the collection of Waclismuth and Springer.

Iii')iiar/<s. — This species is known only from natural moulds and gutta percha casts. We had for description two specimens, one showing the dorsal cup, the other the ventral disk, both presented to us by Prof. J. M. Clarke of Ali)any. The species is readily distinguished from Arthmcanth<i jxiiwto. bnirliiiita Williams by the more depres.sed form of the calyx, the greater width of the costals, the presence of but one intcrbrachial piece and the fact that this is located almost entirely in the dorsal cup, and by the less number and greater width of the .spine-bearing sockets.

t

1^^

tl

HEXACRINID.K.

753

■{

DICHOCBINUS Mi'NSTER.

I'^SS. MOnsteii ; 'Boitr. ziir ritrcfaclcnkundc, T., p. 2.

ISi!). AfsTiN ; Sliiiuigr. Urc. unil Foss, Criiioiils, p. tS,

1850. D'OiiiiKiXT; I'l-oilr. dc riilroiit., I., p. 15fi.

lSr)2. 0\VK\ mill SiiLMAiii); CIciil. Ui'p. lown, Wise, anil Minnosotn, p, 589.

lSj3. ])K KoMMK mill Le Uox; lluch. Criii. Curb, liclg., p. 140.

1857. I'lCTET ; Ti-.iili'' lie Pali'mil., Vol. IV., p. 3;t3.

1800. JIekk mill WnnriiENi I'meooil. Araul. Nut. Sci. riiiin., p. 381.

1500. ll.u.y,; Suppl. (Icul. Hop. lona, p. 83.

I'm'iO. Casskdat ami Lviix (in pmi) ; I'nicecd. Acad. Arts and Sci., Vul. V., p. 10.

1501. IIai.i,; liiisl. .Imirii. Nat. Hist Vol. XIT.. p. 288.

ISOi. DiMAiijiiN and IIi'i'k; Hist, niinrilli? di's ZiKiplutrs licliin., p. 155.

1S03. M'lliTE; I'ldCC'i-d. Bust. >TMnrn. Nat. Hist., Vol. ix., ji. 19.

ISOO. Mei:k and WoiiTiiEN ; Gi'ol. Hop. Illinois, Vol. II., pp. 107 and 203.

1S79. ZiTTKL ; llandli. drr l'alaeontolof,'ie, Vol. I., p. 305.

ISSl. W. ami Si'.; Ucvision I'ala!ncr., I'ait II., p. 81.

1S83. I)e Lorioi,; I'ali'ont. Franvaiso, C.'rimiidcs, I'art T., p. 33.

1S83. AVuKTllEX ; Cii'ol. lU'p. Illinois, Vol. VII., p. 313.

18S5. W. and Sp. j Itrvision I'alrcoor., Part III,, p. 110 (Proceed. Acad. Nat. Sci. Pliila., p. 311).

1S90. ^V. and Sr. ; Ceol. Kep. Illinois, Vol. VI II., \i. 190.

1890. S. A. Mii.i.Ku; North Anier. Geolo-iy and Palicontolopy, p. 239.

Not Hall IS.jS; Gi'ol. Hep. Iowa, Vol. I., Part II., pp. 05 1 and 089; nor Slinmard 1S57; Trans. St. Louis Aeail. Nat. Hist., Vol. I., p. 5.

Svii. Pldlitri-iiiiis (ill part) — Phillips; Geol. of Yorlisliivc, Vol. II., Plate 3, Pigs. 21 ami 20.

Syn. Coli/leiluiioci-iiiiis — Cass, and Lvox, 1800, Proc. Am. Ac. Arts and Sci., V., p. 20.

Calyx oblong, conical to alino.st cylindrical. The dor.sal cup consists almost exclusively of basals, radials, and a largo anal plate. Tiie costals and disticlial<, .iltliough laterally connected by interbracliials, and taking part in the composition of the calyx, more or less, retain the form of arm plates. Plates deliciite ; their surfaces smooth, or covered with longitudinal stria) or rows of small tubercles. Basals two, the suture lino running from the anal plate to the anterior radial. They form together a deep obconical or rounded cup, which in height often equals the length of the radiid.s. Radials largo, subquiulrangular, except the anterior one, which is pentangular; their upper fiices excavated for the reception of the brachials. Costals two, very short and narrow. In some species the axillary costals support the arms, in others those of the distichals or palmars, and the first .and second plate of each order are united by s3'Z3-gy. Arms thin, either uniserial or bisorial, some- times pendent. Pinnules unusually long and rather stout. Interbracliials three, arranged transversel}- ; they rest upon the upper faces of the radials and are succeeded by a number of interambulacral pieces. The covering plates of the ambulacra generally exposed and forming continuous rows. Anal plate frequently a little smaller than the radials, pentangular, narrower at the upper end than at the lower. Anus cxcentric, placed within a wart-

95

J

lOi

TUIC CKINOIDKA CAMKUATA OF NOUTII AMERICA.

like i)iotul)eiiuice, or at the outer end of a sliort conical tube. Column 101111(1; axial canal minute.

Didnbiittiiii- — This genus is largely ropresentcil in, and nearly to tlio close of, the Carboniferous, both in America and Europe ; but not a solitary species is known from the Devonian, nor from the Coal measures.

Tiii>c ol the genus; Dtvhncriiiug radiatus Munster.

licntufks. — There has been some diilerence of opinion as to the number of "primary railials" in Dicliocrinits. The Austins represent their D. fusi- formis* with throe costals, and De Koninck and Le lion, in their generic formula, fix tiie number of "primary radials" at four, on the strength of Austin's figure. Shumard, on the other hand, describes two of his species, D. ciirnifjcnts and D. sexlobatus, with a single large radial followed directly by the distichals. Cassoday and Lyon give the number of "radials" as one to three, and with this Meek and Worthen agree.

From a careful examination of extensive material, we are convinced that all sjiecies of iJic/iocriitiis have three so-called radials, i. e. two small costals above the radial, united by syzygy; but that D. corniijcrns, D. scxlahatus, and the other species for which we proposed the genus I'alwommis, have but one, and this so extremely small that it was overlooked by Shumard.

The genus Cot(jlvihnocrinus Casseday and Lyon is based on incorrect observation. Examination of the type specimens shows that C. jyenialohiis, the type of the genus, has two basals, followed by a ring of six plates, and not by five as described by the autliors.

Dichocrinus lachrymosus Hall. riatc LXXVII. Fif/s. 2a, I, c.

1SJ9. T>it-/in.\-iiiiis luchn/iiiosiis — IIau. ; Siippl. Gcol. Krp. Iowa, p. Si; figured Bull. I. N. Y. State

Museum of N,il. Hist., I'liilc iA, l-'ii;. ]1. ISSl. Vldli/i-riiitts milj'iiimitosiis — W. and Sp. ; Hcvisioii rulTocr., Part II.. p. 75. 1SS5. Vi.-liucriiiiin liielii-i/mosKs — W. and Si'. ; iliid.. Part 111., p. 1 19.

A rather large and grotesquely ornamented species. Calyx large in proportion to the size of the arms, broadly conical, as wide as high ; sides rapidly and uniformly spreading from the base of the basal cup to the base of the brachials ; the radials rounded on the back, producing angular depres- sions along the suture lines. Surface of plates covered by series of prominent wart-like proces.ses of abrupt and irregular form, those of the same plate being generally confluent. On the ba.«al cup, these processes occupy the lower end, there being two or three of thom to each basal, each set separated • Rcc. nad Foss. Criu., Plate 5, Fig. 04.

IIKXACRIXID.E.

100

T

by nn obscure groove, nnd similar grooves, but dccpor, marli (lie :ii(ci1)iisal suture lines. The processes upon the radiiils occupy tiie upper two tliirds of the plates, leaving their lower ends and the upper portions of the basals almost free from ornamentation. The facet which supi)orts the costals is surrounded by a thickened collar, from which three — exceptiounlly two — ridii-cs or series of nodes pass downward ; the two outer ones in the direction of the lower angles of the plates, the other following the median line.

Ba.sal cup large, occupying over two fifths the lieight of the caly.x. Radials considerably wider above than below, their Kngth about e(iual to their width at the upper end ; the lower faces very little convex, the upper slightly excavated ; the facet directed upwards, occupying one third the width of the plates; the limbs somewhat inllected but not notched. Costals two, rounded on the back, the lower very short and linear ; the second a little longer and axillary, its sloping upper faces at right angles. Dis- tichals three, narrower than the costals ; the two lower ones coml)ined but little longer than the third, and united by syzygy, the second giving off a strong pinnule to the outer sides of the rays; the third axillary. Arms gener- ally four to the ray, occasionally five to six in one of the three anterior rays, or in all of them ; they are widely divergent, comparatively thin, rather short, and composed of a single series of cuneate pieces alternately arranged. Ventral disk depressed-convex, the median portions flattened and occupied b}' five, small but well defined onds, from which five rows of comparatively wide but short covering pieces pass out to the arms. The three interbrachial plates are followed by eight to ten interaml)ulacral pieces, distributed in four ranges. Anal plate a little narrower at the top than below, succeeded by five small pieces transversely arranged, which in turn are followed by numer- ous smaller plates forming a protuberance which contains the anal opening. Tiie anus is almost marginal and opens out laterally. Column small, round ; the joints short, the nodal ones somewhat projecting.

Uorkon and Locality. — Upper Burlington limestone ; Burlington, Iowa.

7)/pe in the (Worthen) Illinois State collection.

licmarl's. — This species is readily distingui.ihed from anj- other of this genus by its peculiar style of ornamentation, in which, however, it closely re- sembles Platijcri)ws stthqjiiiuhsiis Hall, to which we erroneously referred it in Part II. of the Revision. The type specimen, which wo had examined, was im- perfect, showing neither the anal plate nor the form of the calyx. Fine speci- mens since obtained by us in considerable number leave no doubt that it is an exceedingly well marked species, and was correctly described as a Bic/iocrtiitis.

4

700 THE CRINOIDKA CAMERATA OF NORTH AMERICA.

Dichocrinus polydactylus Casskday ami Lvon. Plate LXXVII. FUjs. la, b.

1800. Casskday unci Lyon ; rrocccd. Ainer. Aciul. of Arts ami Si'i., Vul. V., p, IS. 1S81. W. niul Sr.-, Uovismn I'liliiwr., Vnrt II., p. 8t.

S\n. J)ii-/ioeriiiii< r.r/ni/iiiis MtEK nml WuiiiiiKN (lint l)e Koiiiiick nml Lc lion 1S63); Proceed. Acail. Xal. Sci. I'liila., p. 3U; also (itul. Hop. Illinois, Vol. V., p. SOU, I'lalu 11, I'ig. 1.

Of tho typo of D. l((cIiri/)iiosiis. Calyx oxpiiiuling rather rapidly along the ba.sals, thence more abruptly to the top of tho radials, where its width is once and a half its height. The calyx in a dorsal aspect is shurjily hexagonal, owing to the convexity of the radials and anal plate, especially in the upper parts where the median portions are conspicuously gibbous, producing an angular depression along the interradial sutures. The basi-radinl and inter- basal sutures arc olso slightly grooved, and the margins of the plates some- what beveled. Surface of plates ornamented with scattered, irregular, wart-like nodes, which show a tendency to form vertical rows. Similar markings occur upon the radials, where they start from the projecting upper rim and run to tho lower end of the plates.

Base large, its height almost one half that of the entire cup; its lower face surrounded by conspicuous nodes, which are sometimes confluent and form a rim around the lower margin. Kadials nearly twice as wide at the upper end as at the lower, the upper face almost equal to the length of the plates; the facet bounded by a heavy, thickened rim. Anal plate wider and longer than the radials, strongly convex in the middle, somewhat inflected at the top. Co.stals two, twice as wide as long. Distichals three; the first and second, like the first and .second costals generally united by sy/.ygy, their suture lines being less distinct than those between the other bracliials ; the third distichal largest and axillary ; it supports on its outer face a simple arm, which .slopes oljliquely upward, and on tho inner face two palinars arranged almost in vortical lino with the distichals, and resembling them in form and size. Tho .second palmar bifurcates again, giving off in the same manner as the preceding axillary an arm from the outer side, and from tho inner two or three post-palmars, which support two simple arms, making four arms from each main division, or eight from each ray. Arms biserial from the fourth or fifth plate ; they are long, rounded on the back, and taper ver}' slightly ; pinnules closely set and of moderate length. Ventral disk higlicr than tho dorsal cup, composed of comparatively largo plates;

1

IIKXACUINID.K.

757

the summit somewlint flattcnud nnd covered hy large oriil.s, from which two row.s of tuberculous covering pieces puss out to the arms. Iiiternidial spsices slightly depressed and paved by numerous riither large plates, all having a small tubercle in the centre; the anal interradius has (Ivc plates in the first row as against three at the otlier sides, and is very wide and bulging, the plates throughout being large, except those innnediately surrounding the anus. The anal opening is placed near the summit in close proximity to the posterior oi'al. Column round, of moderate size, slightly tapering downward, the nodal joints but little wider than the internodals.

ILirhdu 011(1 L'lcdliti/. — Keokuk limestone; Crawfordsville, Ind.

Ti/jjin in the collection of the late Major Sidney S. L\on, Jefl'erson- ville, Ind.

RiiiKir/iii. — Dkhocrbuis c.r/wH«»s Meek and Worthen is undoubtedly iden- tical with this species, nlthough the specimen figured has only six arms to the ray. Moreover, that name was pre-occupied by De Koninck and Lo Hon in 1853.

Dicbocrinus striatus 0. ami Sm m.

rintt LXXVn. Fi,js. J J a. h.

1S52. 0\vi:n .iiiil SiiiMUin; I'. S. Godl. Ucp. Wise, Iciwa, imliI Minn., p. 590, rintc 5./, Kigs. 10^, b. Ibbl. W. 1111(1 Sp. i Uc'visiiiu I'liliiupi-., I'iirt It., |). 85.

Calyx subglobose, widest at the basi-radial suture ; compo.«ed of thin plates, which are thic^kly covered with conspicuous, abruptly elevated, longi- tudinal ridges. These ridges form around the calyx six well defined rhombs, which meet interradially at the basi-radial suture, the acute upper angles of five of them reaching to the radial facets, that of the sixth to the upper part of the anal plate, and their lower angles to the lower ends of the basals. The rhombs are subdivided into two triangles by the basi-radial suture, and the included spaces are occupied by three or four vertical ridges, often with smaller ont's between, which all cross the sutiu'e line unbroken. Other ridges, but less distinct and easily overlooked, fill the triangles formed between the upper sides of adjoining rhumbs, and these as well as those within the rhond).s, when examined under a lens, have an iindidated outline.

Basal cup hemispherical, slightly trimcated at the lower end ; column facet well defined and bordered by the lower ends of the ridges; height equal to that of the railials; superior margin distinctly hexangular. Railials quadri- lateral, narrower at the top than at the bottom; the width at the lower faces

758

TIIK C'lUXOIUKA CAMKHATA OI" XOHTIt AMKHICA.

tMiimllo, or greater tlinn the Ii'iigtli ; tlieir upper fiires one lliiid narrower; facets heiiiieireular, directed ii[)\VMrtl, and oceiipviiij,' one liall'tlio widlli of the plnteH. Anal plate of a niniilar form to the radiidf", lint narrower at the top, the upper portion somewhat bidyiii},''. CoHlals two, vei'^' f<liort. Arms two from eaeh ray, rather strong, hiseriul from the (iflli plale; Ihittciied on tin' haek. Arm joiiitw twice us wide as long. Pinnules heavy and unusually long even for this guniiM. Column tsmall ; the nodal joints consideraMy widest, and their edges knife-like and serrated.

Iloi'kon and Lurulili/, — Upper IJurlingtou limestone ; Burlington, Iowa, uiul several places in western Illinois and Missouri.

Dichocrlnus plicatus Hu.i,. rialc LXXVn.Fi,js.r,a,b.

]^r,\. IIai.i.; W^Um imm. N;it. lIUl., Vul. Vll., p. 2ss.

18sl. W. mill Sr. ; \WsWm» 1";.1,ti«m-., I'miI 11., [.. s| (I'n.crtl. Adul, XmI, Sci. riiilii., p. 2J'').

Of the type of D. .ifrialiis, which it resendiles in the style of oriiamentn- tion ; but the plates are thicker, the ridges upon the plates comparatively larger, loss in number, and the species is snuiUer throughout. Calyx globu- lar, slightly conical at the lower end; greatest diameter at the lower part of the radials, the upper part curving gradually inward. The ribs or ridges covering the surface are undulated and very strong, the inlervening grooves deep and wider in the middle than at the ends. They form six well defined rhombs, distributed around the calyx in a similar manner as tho>e in (ho preceding species; but their inner spaces are occupied liy one or two in place of three to foiu' ridges, and the triangles at each side of the I'hombs, which are longitudinally divided by the interradial sutures, nie .smooth or oidy occupied by low pustules.

J?asals longer than the radials, forming a deep cup with rounded .sides and slightly truncated lower end. Kadials sidjcpiadrangidar, widest at the lower margin ; facets wide, occ\ipying two thirds the width of the plate, and directed upward. Anal plate generally a little narrower than the radials. Costals two, small, supporting two arnis. Arms thin, long; composed of rather long cuneate pieces, which interlock from the fourth or fifth plate. Pinnules stout and very long, the joints three times longer than wide. Column small.

Ilorhon ami Lacaltly. — Upper Burlington limestone; Burlington, Iowa.

Ti/pcs in the Museum of Comparative Zoology.

\

^

IIKXACUINID.i:.

7.VJ

Dichoorinus oblongua w. ami Sp. (nov. spec). I'htcLXSVII. Fiij.O.

Til tlio stylo of orimiiicntation rcsemhliiiy 1). ''ifits, from wliicli it (lilTt'r.M cssfiitiiilly in it^ vory cloiigiitc cnlyx, and in tlie proportions of tlio pliitos. Ciilyx iiImoHt twico iis liigli its wiilc, oJjconicnl, not contnicti'tl nt tlio upper end; tlio sides convex. Surface covered by six nets of from five to six rather prominent, lon^iludinal ridges, wliiuh in gentle curves pass from the facets of tlie radiiils and lop of the anal j)lale to Iho foot of the linsals. These ridges do not cover tiio entire siiriaoe of the calyx, but leave upon ihe lateral margins of ntljoiniiig rndials a trigonal space, divided by the interradial suture, and covered by obscure, longitudinal ridges, which rest obli(iuely against tlie otiier ridges.

Basal cup conical, iilniost as high as the radials, and nearly as high as wide; slightly truncated at tlie bottom; the upper face but little excavated, liudials .....0 and a half as long ns the width of the lower end, a little wider above than below, the lower face almost straight ; facets narrow, a little concave, ami slightly protruding outward. Structure of arms and ventrnl disk not known.

Horizon ami Loculili/. — Warsaw limepionc. near Woomington, Ind.

Ti/j)c in the collection of Wachsmuth and Springer.

Dlchocrinus liratus Hall. riate LXXVIL Fhja. Ja, h, ami Plate LXXVI. Fi(j. 8.

ISnO. IIai.1. ; I'l-iliin. Dcscr. (if Nrw Pnln'oz. Criii., p. 5.

ISOl. IIau; lio^l. Jniim. Niil llisl., Veil. VII., |i. -290.

T<72. IIau, ; N'. Y. Slalc .Mus. NmI. lliM. (linll. l), I'lalc 2./, Figs. 7, 8.

ISSl. W. mid Sp.; Revision Piilieocr., I'int II., p. 8t.

Of the type of D. jxili/iliit'ti/liis and D. larhri/nwsus, difTcring from the former in having four or five instead of six to eight arm.s to the ray, and showing a tendency toward the rhombic sculpturing of D, striatus. Calyx abruptly spreading to the basi-radial suture, and more moderately from there to the arm bases, at which the width \s about equal to the length. Surface marked by a few strong radiating ridges, somewhat tending to form triangles or rhombs, modified by transverse lines; eompo.sed of small, closely

I

I

ruo

niK CltlNolDKA ('A.MKUAIA Ul' NolMll A.MMdl A.

sot, l)c'ii(l-liko iiKico.iKCS, which give to llio riilgett n, soiiiuwhut Hornitod ucpcct. Suturo liiK's i)li>c'ui'o.

IJasals Iiir;ic, occupying two finii.i to one Imlf tho height of the doimil cup, ihiir iowi'i' oiiiU projei'tiiig into ii siiliunt nmrgin; their suifiice covered with I'i-lil riiige.s, t<ix of tlieni nidiuting from tlic column to tho nix fidiciit luijrles wliicii foiiii tlio upper nmigiii of tiiu (U)r.-'al- cup ; tlie two ollici> fdiiow tho inlorbaciil suture. Kadiaitt as long us their width at tho toi), tho median portions obtusely angular, projecting outward, especially in I he upper part, where the outer nuirgins of tho plates Ibruj a depression or groove along the inlorradial sutures; tho outer edges of the facets sur- rounded by a large, (|uito proininent, thickened rim, from which two ridges pass out Id tho lower angles of tho jdates. The spaces between tiieso ridges and those of tho basals arc marked with a few small nodes, wliich below tho bii.si-radial suture are arranged in transverse lines. Tho upper lateral angles of the ladials are not truncated, and the facets are shallow. Anal plate similar in I'oiin to the radials, but narrower and angular at the top. (Jostals two. short, and closely united. Distichals throe; tho length of tho two lower plates tog.'liii'r about eipial to that of the third. Arms four to tho ray, suljcylindrical, very little tapering; composed of two rows of rallier largo interlocking pieces. Pinnules long. iStructuro of the disk not known. Column round and of moderate thickness; the joints veiy even and short near the calyx, but growing longer downward, and the nodal joints project- ing above the internodals.

Jfiiri.V'in Kill! f.'niili/^. — Upper Biu'lington limestone; Burlington, Iowa. T'/j/c in tho University Museum at Aim Arl)or, Michigan.

DichocrinuB ovatus o. .uut .s;iii >i. PM.' LXXVf. nil. r, and Phifr LXXVIl /'/>. 8r/, h.

\<ii. Owr.N :inil SiirMMin; V. S, fii'ol. l(i|i. \Vi«c, Imvn nml Minn., I'iiil II., p. SOU, riato .')./, l'ii:>.

11./, Ii, c. ISSl. AV. :uM Si'. ; l(,vi»i(iii I'alivncr., I'lirt II., p. SI.

Form of caly.x ovoid, higher than wide, widest across the middle of the radials; the edges of the plates slightly beveled, and the suture lines well defined ; plates strong. The basals form a rounded, .somewhat conical cup, which at its lower end is truncated and slightly excavated. The truncated part is completely filled by the upper face of the column, and there is around its edge a ring of well defined spinous nodes. The sides of the cup are

IIKXACHINID.E.

701

(k'liMily covered hy small gmiiiik.s nnanged in row some of wli i run from tlio truiiciited Inver part tu the upper faeex, and n wvmowlmt stru -^r one t" each angle; otlier-< run parallel to llie undulating upper niaigiu.

Ilasals largo, occupving more than tlireo I'iglitlis tlio lieiglit of the eal^Tl. HailiaU varialilc in form, hut alwayn lunger than vviile, nn<l narrower ni t, upper face than at the lower; their orujimenlation is himilar to that of thu hasnlf", con.xiHting of narrow rows of granules passing up and ilown the plates, and others crossing them transversely; facets occupying ahout one half the •wiilth of the radials at their upper end, shallow, and direcled upwards. Anal l)late generally \vi<ler at the hottom than the radials, an<l narrower ahove ; the lower faces distinctly angular. Costals two; the first shorter than the hii'urcating second. Arms ten. strong, slightly tapering upward, and hiserial. PinnulcH very long and closely packed ; composeil of si.\ or seven joints, each one about eight times as long as wide, Structure of the ventral disk, and form and position of the anu.s unknown. Column round, the nodal joints larger and rounded at their edges, the internodals (|uilc short.

Ilurlznn iiiid Lvcalifi/. — Lower Ilurliugton limestone, Burlington, Iowa.

DichOOrinUS linoatUS "SU-.m mul \V(iiirm:\. Phitc LXXVI. Fiijs. 4a, 0, c.

1309. Mbkr nml Wortiikn j PrDCrcd. Acnd. Nut. Sci. I'liilii., p. fiO.

Wi. Mkbk nnd W.jutiieni (iv«\. Ili'p. Uliiiuj.,, Vul. V., p. IHl, I'lale 3, Fi(,'s. l/(, 6, e.

18S1. W. nml Sim Uivisidii I'liln'ucr., I'liil 11., \<. St.

A large species, intermediate between D. ovuIkh nnd JJ. jhxhdi, with delicate longitudinally striate ornamentation. Calyx pyriform, about as wide as high, not rounded at the base as in the former, nor llattened as in the latter ; it is widest at midway, and contracts but little at the upper end. Sinface densely and uniformly covered with minute, closely arranged longi- tudinal ridges, proceeding in parallel lines from the upper part of the radials downward; those following the median portions of the plates continuous to the foot of the basal cup, the outer ones meeting at acute angles ^,'ith corresponding ridges from adjacent radials. On the anal plate, in which the upper face is mucli narrower than the lower, the ridges run parallel to the lateral margins of the plate, and nieeL the inner ridges at acute angles in a similar manner to those upon the basals.

Basal cup conical, with slightly curving sides ; its height equal to the length of the radials. Basi-radial and interradial sutures rather well defined.

^

762

TIIK C'RINOIDKA CAMKUATA OK NOUIII AMKUICA.

liiulialft 11 lilllc loii}(or limn wido, tlio lowi-r Iiu'cm moiK'mli'l>' convex ; tlic liiloriil iiiii'H iiaiiill«.'l ; llif ii|ipi'i' nuiirly ftiiiiglit. not ,>.1(i|m'(1 itl tlio oiitiT cikN, iiMil bill lilllo iiniiiLwc'd lit the liioct, wliicli !.•< narrow and nonu'wlial lliii'k- L'nod aioiuid the margin. Anal pluto genemlly wider at the lower end than the nulialH, an<l one fourth narrower at the top; its lower face ohtucely angular. All parts ahove the radials unixnown. t'ldunm roinid and small.

Jl'iiixmi mill /,'iiii/i/>/, — Lower Hurlingtun limestone, IJurlington, lowu,

'J'l/jii. in the Museum of Comparative Zottlogy.

Dicboorlnua omatua w. miil sp. I'liik LXX\'I/.ri!/.n.

bSl. Dii-hfi-iiiiit iiriiiilim — W. iiiiil Hp.i Hcvinluli I'lilinicr., I'lirl II , p. SI.

Svii. Itirtiuniiii' sriili,lin — i'\*M\>\\ niul I.VdN (mil Di' Kniiiiick iiiiil I,i! lliiii, Wh\)\ I'rnoccil. AiiiiT. Aciicl. Arts ami Sci., Vul. V,, |i. ijj.

A very small speeien. Calyx to the top of the radials ahont tt.s wide no liiyli ; regularly cup-shaped ; hroadly trimcaled at the lower end ; the sides a little convex ; the upper margin slightly contracting. IMati'.s covered by cons|iicuous. irregular, undulating ridges, two of which descend from the top of the dorsal cup to the foot of the basals, two others olditiuely in the direction of tlio lower lateral angles of the radials, touching slightly the upjicr end of the hasals, and two shorter ones pass out to the lateral faces of the railials.

llasal cup sancer-slmpcd, occupying two fifths the height of tho calyx ; the truncated lower face surrounded by a well defined undulating rim. Itadiiils a little longer than wide, widest at the top; facets small and pro- jecting outward. Anal plate almost us large as the radials, narrowest ahove. Costals two, short; occupying less than one half tho width of the radials. Disiichals two or three. Arms four to the ray, slender ; composed of long cuneate joints which gradually interlock without being truly bi.serial. I'iii- iiules long. The arms in most of the specimens are spread out horizontally. Ventral disk low-convex ; ntius directed laterally. Column round ; the nodal joints projecting and provided with one or two long cirri.

Jfnrizon mill LnntJilij. — St. Ijouis group; tho typo specimen in the collection of Major S. S. Lyon caino from Ilardin County, Ky., that figured by us from near Mt. Pleasant, Iowa.

liiiiiiirl-^. — This is tho smalloat known species of Dwhorriinis, and is readily recognized by tho spreading arms, long pinnules, and tho stria; along the calyx plates.

3

IIKXAMIINID.K.

7C3

DlohoorlDiia ooxanui WonTiirx. /•A//, I.XXVl. yiu.o.

liir WonTiir.N ; (icnl. llrp Illiiuns Vnl. VII., |i. III.). I'l.iir il7, Kiirn. 7.

Its.V W, iiihl Si', i III UMnii I'ul cr,, I'lirl III , |i. I Ji< (I'mcnil. Arm!. Nul. 8ri, Pliiln., |<. Wi).

A very mimll iiml »lt'iitlor upocioH of tlic \y\M' nf />. iininhia. Culyx ovnto, nliiio,st poiiiti'd lit, till' liiwiT cml, coiiHtrieUMl uciiw.'h tlii' I'Of^tulH ; gruiilfHt tlin- iiu'ti'r 11 littlo uliovo lln' Ita^'i-i'udial siitiiii'. Siiil'iiuo of tin- plutes covtMi'd ^vit)l irrci^niliir Inii^riliuliiiiil I'id^a'H, iVnui {\\\w (o four locacli plate, wliicli nni |iiii'alli'l to tlio latfial liorilui'H ol tlu> railiuU, and art' t'onliiiiu'd aloiij^ tliu bannU to the coliniiii.

Dawalrt iiM Ioti{? M tlio radials ; foriiiiiig a rntlior liij,'li, obronicnl oiip. with a very iiiirrow columnar iittiiolmuMit. IJadiulM loiij,'('r tliaii wido, tlicir lowtM* fiici's iiiodi'i'atcly coiivi'x. tilt! Iiitcriil rncc.'H nearly pandlel, tliu upper margins constricted and to nearly one liall' tlieir width excavated for the I'acetM. Costal.t two, very whort. forming a t^yy^y' Arms ten, Hlcndcr, roinided on (he hack; composed of .><lightly cuneatc piece-*. I'iininles long. All other parts nnknown.

IIiir'r.iiH mill f,iiriili/i/. — Upper part of Keokuk limestone (Crnwfordsvillo division), Hamilton, Illinois.

7''//>c in the collection of Mr. T-. A. Cox, Ki'okuk. Iowa.

Ill iinirhs. — IHrliiirn'iiiin in iiiiliix, w\i\\ which this spceien ha^ the closest nfnnities. has twenty arms instead of ten, the calyx is less ctunlracted at the arm hascs, broadly truncated at the lower end, and it conii ^ from a dilVerent hori/on,

Dlchoorinus pisum Mkkk nni Wdiniu-N-, Plate LXXVJ. Flij. o, „>iil Phil,' LXXVII. Fig. 10.

l«nn. Mkfk mimI Wmutiikn; I'rocci'il, Aivul. Nut, Sri, riiilii., y. li'J.

!><;;), .\ln K mi.l W.iUTMKN ; (l.nl. Itc|,. llliiHiis, V.il, V„ p, tH, I'lnlc 3, Fips, in. //, c.

I'o-l, W. ,'iiul .><.■.; Iti'visiiiM r.ilinirr. I'lirl II., |i. SI (I'nicci'il. Acn.l. Nat. 8ci. I'liilii., |i. i.')').

Of the type of 7). /i/!rii,,is, hut the calyx, instead of globular, sub([uadran' gular in outline, the basal portions more or lc,ss flattened, and the .sides along the radials but very slightly convex. It also re.seud)les D. Uncdlim in the stylo of ornamontation, but the ridges are coarser and more prominent, and the b.isal cup proportionally smaller and less conical. Height one fourth loss than the width. Plates thin; the radials covered by from six to eiglit

(04

TIIK CKIXOIUKA CAMKUATA OV NORTH AMKHICA.

striic '.(.•rliciilly arranged, and all contimicil to the basals, whore the coire- sponiliiig OIK'S meet witli tlioso from adjoining radials at acute angles; the stria' in well preserved specimens showing a rliombic arrangement.

Basal cup rather Hat, i)resenting a shallow basin; the columnar attach- moiit very small. Kadials a little longer than wide; the lower faces a little convex ; facets shallow, occupying about one half the width of the plates. Structure of the di.sk and arms unknown.

IJiiriion and Loaditij. — Lower Burlington limestone; Burlington, Iowa.

Ti/iic in the Museum of Comparative Zoology.

Dichocrinus oinctus :\riLLF.i! and Giulet. Phdc LXXV. Fhj. ,5, and Platv. LXXVII. Figs. 4a, b, c.

ISflO. ^tii.i.KR iiiul GrHLKV; Joura, Cinciii. Scic. Nnt. Hist., Vol. XIII., p. 21, Tlatc i, Figs. 10 to 12.

A small and slender species. Calyx fusiform, widest across the middle of the radials, whence it tapers both ways; cross section circular; suture linos indistinct ; surface of plates highly ornamented. The radials are covered with five or six longitudinal ridges, which follow the median portions of the plates to near the foot of the basals. The ridges do not quite reach the top of the radials, and their upper ends are rather obscure ; but toward tlie lower end, and especiiiUy upon the basals, they grow quite prominent, and terminate in a sort of thickened collar around the column facet, giving to the specimens an appearance as if the inner part of the base con.-^isted of an independent set of plates. The longitudinal ridges are faced laterally by horizontal ones, which traverse the interradial sutures, and enter the margin of the adjoining plate.

Basal cup obconical, rising to two fifths the height of the calyx, the upper angles slightly bending inward ; radials somewhat projecting next to the facet into a lip ; facets directed upward, not occupying more than one third the widtii of the plates. Costals short, very closely united. Arms free after the first bifurcation ; simple, slender, long, and iiniserial throughout ; joints convex, slightly cuneate, and very short; the two proximal ones united by .syzygy, with striated, apposed faces (Plate LXXVII., Fig. 4c). Pinnules in close contact, and of moderate length and width. Anal plate longer thiin the radials, and more inllectod at the ujtper end. It supports a number of small irregular plates, which form a small protuberance enclo.s- ing the anus; the latter opening out laterally. Ventral disk low-pyramidal;

1 ■

/

IIEXACRIXIDvE.

766

the summit coverud by a largo, single oral plate, from the sidcw of which the covering pieces pass out to tiie arms. Column large compared to the size of the species ; composed of liigli joints with serrated edges.

Iforhoii ami Lmilifi/. —Khuhn-hook group, Le Grand, Marshall Co., Iowa.

7"i/pts in the collection of Mr. Wm. F. E. Gurloy, Danville, Ills.

n ■

Dichocrinus leevis Hall, Pkle LXXVII. Figs. 7a, h, c.

1SJ9. II.iLl ; Suppl. Gcol. Rep. Iciwn, V(.l. I., p. S3. ISbl. W. nnd Sr.j Revision I'lilivocr., Part II., p. St.

A beautiful little species. Calyx goblot-shaped, obconioal to the basi- radial suture, not expanding above; the cross section slightly hexagonal. Plates remarkably thin and flat, their surfaces thickly covered with small granules.

IJasals forming a small obconical cup, which extends to about one third the height of the calyx, and sometimes a little higher. Radials nearly as long as wide ; the sides parallel, except in the tivo posterior rays, where they are wider above ; the lower faces moderately convex ; the upper almost straight; facets small, occupying but one third the width of the plates; their lower margins slightly thickened. Costals two, a little wider than long ; the second sharply pentangular. Distichals almost as wide as the costals, the lino of union between the first and second loss distinct than that between the succeeding joints ; the second giving off cither a very large pinnule or an arm; in the former case somotimes another bifurcation takes place higher up. Arms unisorial, long, rather stout, very little tapering; composed of cuneate joints alternately arranged, which at the tips do not touch the opposite side of the arm. Pinnules long, very stout, and not in contact; the joints as wide as long. Intorradials not visible from a side view. Anal plate a little higher than the radials, narrowest at the upper Olid, and distinctly angular at the basi-radial suture. Anus placed near the margin of the ventral disk, in the middle of a small protuberance. Column round, small.

Ilorl~oii (tnd Loccditij. — Lower Burlington limestone ; Burlington, Iowa.

The specimens figured are in the collection of Mr. F. M. Fultz, of Bur- lington. Towa.

TOG

THE ClUXOIDEA CAMKHATA OF NORTH AMKUICA.

Dichocrinus delicatus W. and Pp. (nov. spec). Flak LXXVIL Ftcj. IJ.

Of tlie type of Z). irvix, but siniillur; tlie calyx more elongate, Its hoiglit twice its width; cros.s suction circular; plates thin anil aiiparently without oinanientation ; suture lines indistinct.

Uasals occupying two fifths the height of the dorsal cup, the sides a little convex. Kadials fully twice as long as wide ; the lateral faces about parallel; tlie upper I'acc nearly straight, not sloping a. the sides; the facet for the reception of the brachials slightly indented, occupying less than one half the width of the plates. Primary brachials two, siioit, of eipial width; the sec- ond a lillle longer, its upper sidfs rorniing an obtuse angle, and giving off two anus which remain simple throughout. Arms long, cylindrical, but little tapering; uniserial, composed of very short qua('irangiilar Joints ; their upper and lower faces almost parallel; the pinnules in rather close contact, long, .slender. Anal plate of etiual length with the radials, the upper end narrower than the lower. Ventral disk and anal opening not visible in the specimens.

Ilorivi))). (Di'I Lordllti/. — Kinderhook group of Jlarsliall Co., Iowa, and Lower ]5iu'liiigton limestone of lUirlington.

T'/jKx in the collection of Wachsmuth and Springer.

llijiiiiirks. — Diiliocy'iiiti^ (Ji/ivafia made its ai)pearance before D. keris, and may bo regarded in a phylogenetic •ense as the earlier stage of that species, as indicated by the arm structure; the arm joints are rpiadrangidar i?i the several specimens found, while in that species they are cuneate and inter- locking at the tips of the arm.s. Besides, this has invariably two arms to the ray instead of four as in D. hvrk, and the specimens are generally smaller.

Dichocrinus siiperstes w. ami Sr. (nov. siicc).

P/a/r LXXVT. F/ff. 11

A small species of the type of Z>. di/icitlitx. Dorsal cup obconical, higher than wide, spreading more rapidl}- at the basal cup than from there upwards. Cross section hexangular, owing to an angularity passing from the radial facets and upper part of the anal plate to the lower ends of the basals. Plates without ornamentation, thick, and the sutures obscure, except the interradial, which are somewhat grooved at the upper end.

iiexac'uimdj:.

roT

Biisal cup iiboiit two thirds as Iiigli as tlie rndials ; the saliuiit angles obtuse and lie uitervening spaces very little concave ; cohunn facet small, rtadials from one third to one half longer tlian wide; irregular in form, some of them much wider above than below, otiiers of nearly equal width through- out ; the upper faces distinctly sloping at the sides, forming rather deep notches for the reception of the interbrachials ; facets but slightly excavated, occupying a little more than one tiiird the widtii of the plates. Anal plate generally narrower than the radiids. Costals two, comparatively large, supporting two simple arms, which from the third or fourth plate up are composed of two series of transverse pieces alternately arranged. The arms are heavy throughout, bisorial, and rounded on the back. Pinnules cylin- drical, \pry long and stout. All other parts unknown.

Ilorlnon and Luculiti/. — Kuskaskia group; Pulaski Co., Ky., and Ilunts- ville, Ala.

Ti/2)c in the collection of Wachsmuth and Springer.

L'< marl's. — The form of the calyx, thickness of plates, deep notches for the reception of the interradials, and the stoutness of the arms, arc character.s which distinguish this species readily from I). (hUvatus.

Dichocrinus scitulus Haii.. riate LXXVIII. Fnp. lui, h, and I4.

Isiil. IIau,; ,Touni. Host. Soc. Nut. Ilisl., p. 2>^9.

l^li. IIm.1.; \. Y. Sliito Museum X.'it. Hist., Hull. I., I'liitc 2./, Fitrs. 12 aiul 13.

ISiil. W. iuiil Sr.; Uovision ralavicr., I'lirt 11., p. St.

Svii. Dli-h'vriinis iwrillim Hai.i,. \^f<\ ; h»m\. nc.sl. S.ic. X;it. Hist., p. 291 j figured Bull. I. N. Y. State Mus. Nut. Hist., F .te i.l. Figs. 10 iiud 17 {""t 11 = D. I,tch).

Larger than the two preceding species, the calyx more conical, the radials comparatively shorter. Calyx obconical, less rtipidly spreading at the radials than along the basals. Plates thin ; their surface smooth or iinely corrugated.

Basal cup nearly one half the height of the calyx to the arm bases ; column facet small, circular, sliglitly projecting. Badials a little wider than long, narrowest at the lower end, the upper face but little sloping at the sides ; somewhat elevated longitudinally in the middle, forming an ob.scure ri<lge, which disappears before reaching the basals ; facets semi-circular, nar- row, occupying less than one-third the width of the plates at the toj). Costals small, bending outward ; the first very short, linear ; the second depres.'?ed pentagonal, sharply angular at the top. Distichals divergent, as long as wide, and almost as wide as the costals ; the second one axillary,

708

rilK CUINOIDKA CAMKllATA 01" NOHTIl AMKKirA.

siippoi'tiiig (wo ni'iiis from eacli division, or four to tlio nxy. Anus divorgciil. long and riitlier slender; composed of modenitely long cuneiUe pieces, wliicli griidnaliy intorlociv, and from about tlie eighth piate are strictly biserial. Anal plato narrower than the nidials, its sides almost parallel. Form and position of the anus uid\iio\vn. Cohnnn roimd and small.

Ilurizim and Localili/. — Upper and Lower Burlington limestone; Uurllng- ton. Towa.

The specimens figured arc in the collection of Wachsnuith and Springer.

7i'r;H«/'/'s. — Hall's D. jiocillum, Bull. I. N. Y. State .Afuseum, Plate 2.1, Figs. IG and 17, is a large example of this species, and his figure 11 on the same plato is probably D. livrln.

Dichocrinus angustus Whitk.

P/utcLXXVf.Fii/.Jl.

isr,2. Wmn;; I'l-doccil. liost. Soc. Nut. Hist., p. 1!). ISSl. AV. and Si'.; ltc\i>iciii I'alxdPr , I'ail II.. )). «3.

A small and slender species. Calyx nciirly twice as high as wide ; sub- ovoid ; \{iry little spreading above the basals, the upper end slightly con- trading. Plates without ornamentation or convexity beyond their general curvature. Suture lines not grooved or indented.

Basals forming a cup with rounded sides; the face for the attachment of the column not protuberant ; it is circular and proportionally larger than in the precL'ding species. Radials nhnost twice as long as their width at tho basi-radial suture ; fiicets wide, but shallow, and pointing upward. Costals two. forming a syzygy, each i)late marked b}- two small nodes. Distiehals thiee ; the two lower, which form a second f'yy-yiiy, together but little larger than tiie third, or axillary. Arms four to the ray, composed of a single row of sliglitly wedge-shaped plates. Pinnules long. Anal plate a little wider below than at the top. All other parts unknown.

llnri-on ami Localitij. — Upjjer Burlington limestone; near Burlington, Iowa.

Tijiiix m the Museum of Comparative Zoiilogy.

liciitiirl\i. — This species is so closely allied to D. hrrU Hall from tho Lower Burlington limestone, that there is reason to doubt whether it is a gooil species; however, as a rule, tho specimens from the upper bed are smaller, the arm plates less cuneate, and there are, so far as observed, always four arms to the ray, which are invariably given off from the third distichal.

IIKXACIUMIU:.

7C9

Dichocrinus crassitostus White. riute LXXVI. Fiyn. Ga, b, c.

18fi2. Wiiitk; Vrnoccil. Host. Soc. Nat. Hist., p. 19. ISSl. Vi'. iiiul Sr. J Ituvibiuii, rulteucr., VmI 11., p. S3.

Of motlcratc size. Calyx up to the arm bn.scs once and a half as liifili ns wide; cylindrical along the radial.^ obconical below; the posterior side extended into a short conical tube, siii)ported by the larj;e anal plate ; ventral disk depressed-convex ; plates perfectly smooth ; the suture lines rather obscure.

Basal cup fully one third the length of the cal^-x ; conical, the sides straight, the lower end sufhciently truncated to form the columnar attach- ment. Kadials twice ns long as wide, the sides parallel or nearly so, th(( lower margins convex (at the anterior plate obtusely angular) ; the upper faces excavated to three fourths their width, slightly sloping at the ends. Costals two, linear, their combined length less than their width, and so closely nnchylosed that the lines of union are seen with dilTiculty; upper face of the second plate very obtusely angular. Distichals 2 X 10, nearly one half narrower than the costals, equally short, and anchylosed in a similar manner. Arms four to the ray, rather delicate, twice as long as the cal^x ; composed throughout of a single series of short joints, united by parallel sutures. Pinnules of moderate size. Anal plate of the same width ns the radials, but considerably longer; its lower face distinctly angular, the upper truncated, slightly sloping to the sides, and supported by three medium-sized plates, which form the base of an anal tube. The tube is rather short, conical, placed at the margin of the disk, but bending inward to a position between the arms. The plates of the interradial series are not numerous ; the three in contact with the radials are followed by two intcrambulacrals, and these by a third. Column small, composed of circular joints, which increase in length downward, the nodal joints longest and widest.

Horizon and Locality. — Upper Burlington limestone ; Burlington, Iowa.

Ti/j>e in the Museum of Comparative Zoology.

Ecmarks. — This species diflers from all others heretofore described in the form of the costals and distichal.?, and in having an anal tube.

97

4

I

770 THE CKIXOIDKA CAMERATA OV NOK'l'II AMEUICA.

Dichoorinus conus Mm-k and Wouthek.

I'M. LXxr.Fi'j.a.

ISOO. Mkkk and Woutiiks; I'l-ncixd. Aciul. Nul. Sci. riiihi., p. ;^^l ; niul (ic(il. Ui'p Illinois, Vii II,

p. lfi',1, I'liilo 1(5, Kics 5//, 4. ISSl. \V. Hill! Si'.; Ucvisioii I'liliiMicr., I'liil II., p. SH.

Largo for tliis goims. Ciil3-\- ol)conicnl ; widtli nml length ns four to five ; constricteil nt the upper end ; distiiiptly licxasroiial in outline, a keel- like angularity proceeding from tlic radial faeet all the way to the lower end of the hasals. Plates thin, without ornamentation, and unite'' by closely fitting linear sutures.

Basal cup obconieal, nearly as high as the radials, the sides perfectly straight ; the basal concavity unusually small, being not larger than the widtii of the column; the re-entering angles at the upper face deep. Radials varying in size, their length from once and a halt to twice their width, the antero-lateral ones wider than the others, but nil increasing in width upwards ; facets surrounded by a thickened angidar vim, occupying nearly one third the width of the plates, and extending down to about one fifth their length, forming large limlis at the sides, which bend decidedly in- Avard. Anal plate narrower than the radials, hexanguhir, fully twice ns long as wide; the sides nearly parallel. All other parts of the species unknown.

IIi>rh.(in ami LnraJil//. — Lower Burlington limestone; Burlington, Iowa.

T'//H' in the Illinois State collection, Springfield.

RemarJcK. — DilTering tVom nil other species in the Inrger size, the angu- larities which extou<l to the whole length of the cup, the constriction of the cup at tiie upper end, and the great depth of the radinl facets, with well defined limbs at the sides.

Dichocrinus inornatus w. ami Sp.

Pl<ttc LXXVII. Fi,j.s. 12,1, b.

1S90. W. and Sp. ; Gc.d. Ucp. lllinnis, Vol. VIII., p. 190, Pliite IC, Fig.s. I and 2.

Not above medium size. Calyx subovoid ; the sides uniformly curving from the column to the arm bases; the ventral disk almost fiat. Surface of plates devoid of ornamentation or other marking.s, except a faint longitu- dinal angularity along the middle of the radials.

h

I

t

IIKXACHIXID.i:.

771

li

Biisals largo, occupying fully one tliinl the height ol" the ciilyx, and lorui- ing a rounded cui) with obtuse angles uiiuu the upper face ; the eoluuin faeet circular and slightly projecting. Radials one (juarter to one half lunger than wide, a little contracted at their lower ends, somewhat bidging at the middle portions, and abruptly inflected at the upper ; facets less tlian half the width of the plates. Anal piece about the size of the radials, but narrower at the top and more distinctly bulging. Costals two, small ; the first quadrangular, twice as wide as long; the second a little larger and triangular, the upper angle rather .sharply pointed and bending inward, its sloping sides concave. The line of union between the two costals, compared with those above and below, quite obscure, constituting a s^zygy, the cpizygal joint supporting an arm. A second syzygy unites the two proximal arm plates, with a pinnule given off from the second. Arms two to the ray, twice or three times as long as the calyx, comparatively stout, tapering to the tips, and biserial from the third plate up. Arm plates of moderate length, with faces transversely parallel ; tlie two series united by a zigzag suture. Pinnules extremely long, rather stout and closely packed; they are composed of from ten to fourteen joints, about three times as long as wide. Plates of the regular iuterradial scries three and two, all forming a part of the ventral disk. The anal side has five plates in the lower range. Orals arranged in the usual way ; the posterior one largest and pushed in between the other four. They form a slight elevation, from which six well defined ridges pass out to the margin, five of them ambulacral, which divide and follow the arms ; the sixth con- nects with the anus; the ambulacra! ridges are composed of two rows of irregular pieces. The column in .several perfect specimens averages eight to nine inches in length ; it terminates in a fine point, and gives ofi' at inter- vals, one by one, short cirri. All stem joints, except close to the calyx, are of equal le.gth, and the older or nodal joints cannot be distinguished from the intervening younger ones. Axial canal minute.

Ilorison and Lncaliti/. — Kinderhook group ; Le Grand, Marshall Co., Iowa, where it is one of the most abundant species.

Ti/pcs in the collection of Wachsmuth and Springer.

. ,sl.ii,»^.=&fatm^^4A^^.^ X

772

THE ClUNOIUEA CAMEUATA t>l' XOUTIl AMERICA.

Diohocrinus Ulrlchi >rii.Lr.nan(lGiuLKY.

1S90. Joiiru. Cinoiii Soc. Nat. lli,-t., Vnl. XIU. (Aiillior's Eil, p. IS), I'lut.' 8, Tig?. 12 mid 13.

A .small species. Cnlyx subovoid. once mid a Imlf n.s liigh ns wide, somewhat constricted at tlie upper end, pointed at the lower; the plates smooth. Ba-^nl.s large, forming a higli oijconical cup, with a deep notch at the anal xide; the column facet small. Radials nearly twice as long as wide, spreading upwards, reaching their greatest width at three fourths their height, contracting at the upper end; the sides slightly dopresscJ, leaving the sutures rather distinct ; facets narrow, and occupying but one third the width of the radials. Costals two, apparently united by syzygj', as well as the two proximal disticli.als, both being so closely iniited that the lines are frequently invisible. Arms two to the ray, rather long and comparatively stout; they are composed of single joints, of which the upper and lower edges are almost parallel, and not so decidedly eunoate as '^gured by Miller and Gurley. Pinnules coarse, long, ar ^. closely packed. First interbrachial plates visible in a side view. Anal p! .tc a little longer and narrower than the radials.

Ilarhon and Locali/y. — Upper part of the Keokuk group ; Bono, Law- rence Co., lud.

Ti//jc in the collection of Wm. F. E. Gurley.

licmarl's. — This species resembles so closely Dkhocrinus sd/iihts from the Upper Burlington limestone, that wo doubt if the two forms represent dillerent species. Wc find it impossiljlc to separate them in our collection, in which we have specimens from both horizons.

•i»»

DichocriQus Hamiltonensis WonrnEx. Pkttc LXXVI. Fig. 10.

1852. Bulletin I., llliiiiiis Sl.ito Miispuin Xiit. History, p. 35.

iss;i. (icoi. R.'ii. iiii.iuis, V..1. VI 1,, |i. ;n;i, riati' -2;, ri^-. in.

A little larger than the preceding species. The specimen from which the description was made, and the only one known to us, is badly crushed, and the exact proportions of the calyx cannot be given. From its appearance, however, we take the length of the dorsal cup to bo about equal to its width, and the height of the basals about half that of the raditds. The latter are subquadrangular, narrower at the lower end, the length equal to their

•'««.

IIKXACIMMD.K. 773

greatest wiiUli, the .sides stniight, the facet for tlio reception of tlio costals narrow and but slightly excavated. Costals two, opi)arcntly followed liy a single distielial, no lino of division being visible in the speeinien. Arms four to the ray; of niedimn length, lather strong, and composed of long, cuneato plates, which slightly interlock. Pinnules stout, long, and not in contact. Anal plate narrower than the radials, but longer and ratiior dis- tinctly angular at the lower end. Structure of the ventral disk unknown. Plates of the calyx without ornamentation.

ILiflmi ami Lucttli///. — Up[ier part of Keokuk group ; Hamilton, Ills, RviiKirks, — Profe.s.sor Worthen described this species as having probably two arms to the ray, which is certainly incorrect. It is clearly shown from the type specimen in the collection of Mr. Lisbon A. Cox, whi<di we have figured, that it has four arms, and ])ut two costals followed by a disticluil, instead of three costals, as he supposed.

Dichocrinus Huntsvillse w. and Sr. (nov. spec). riute LXXV. F!u. 4.

Sv'i. Pliili/criiiiD pumilim Meek imcl Wuutiien; 18ii5, Gcol. Ui'p. Illinois, Vol. V, p. 5J5, Pliite 20,

'r>s- 7.

Of very small size. Dorsal cup gradually spreading to the fop of the basals, the sides along the radials almost parallel. Plates delicate and per- fectly smooth, the suture lines indistinct. Dasals forming an obconical cup, of which the height is equal to two fifths the length of the calyx to the arm bases. Kadials twice as long as wide ; the two posterior ones considerably wider above than below, tlie sides of the three anterior ones almost parallel ; the upper faces nearly straight, their median portions but sliglitly excavated, and the sides but little sloping. The anal plate narrower at the top than the radials, but wider at the lower end. Costals two, more than twice as wide as long and about half the width of the radials; the upper faces of the axil- lary somewhat concave. Distichals two, frequently as largo as the costals, the first sometimes a little narrower. Arms four to the rn}-, small, rounded on the back. They are composed of a few transverse single pieces, followed l)y cuneato ones, which gradually interlock, but the smaller ends do not reach tlie sides of the arm. Pinnules long and stout. Structure of ventral disk not known.

Horizon and LocaUti/. — St. Louis group; Iluntsvillo and Whitesbnrg, Ala.

Ti/pcs in the collection of Wachsmuth and Springer.

Tin: c'i;iNnii»i;A camku.vt.v oi' mumii a.mlkic.v,

Dicbocrlnus pendens w. iin'l si . (nuv. hiicc). I'hilr LXXVIll. /•/'/. AT.

Of iiieiliiiiii si/i'. Calvx iipiKuontl}' suliovoiil. a little liij;Iit'r than wiilr ; tlio jilutL's very dulicate ami willioiit oniamoiitalioii ; the wutiiie lines not grooved ; tlie arms j. ■lulenl.

Dasal ciiii buwl-HJiaped, the plates a little shorter than tho radials. Badi- al-i nearly imee and a hall' a.i wide as loiij,', widest at one third their height, the .sides heinj^ dislinctly convex; radial facets directed iii)waids, rather shallow, hnt wide, and occnpyin;^ I'onr fifths the width of the plates at tho upper end. C'oslals two, short, tiie njiper wider than the h'^ver. Distielials two, axillary, giving off loin' arni.i to the ray. The arms from tiie fouilli or fifth pahnnrs cnrve abruptly downward in sneli a maimer as to envelope the caly.\ and ihe njiper part of the stem, exposing the ventral furrows of ariii.s and pinnules. Arms ton, l)i>erial at the np|H'r ends, the lower arm joints cnneate, nlternately arranged. Pinnules stout, long, and llattened. Colnuin round ; the nodal joints w ider and longer than the internodals, the latter, po far as ohserved, consisting of a single ossicle to tiie internode.

J/iiir.dii 1(11(1 LdddUj. — I'pper ]5urlingU)n liiiieslone ; IJnrlingtoii, Iowa.

7''/^;i > in the collection of Wachsmuth and Springer.

Ii((((i(ii.s. — Distinguished from all preceding species Iiy the pendent, anus, which is a constant feature in half a dozen specimens.

DichOCrinUS flCllS 'ass. and Lvov.

riuh LXXVIll. Fi'js. Ida. h.

IsfiO, CAssrOAV ami T.Yox ; Prncp<'(l. Amcr. Acad. Arls niul Sri., Viil V., p. 3t.

ls;:i, Mkkk ami WnuTiux; (1.^)1. lirp. Illinois, Vul. V., \y SUi, I'late 11, Figs. 5«, A (not iljiJ., Vol. VI.,

I'lalc i'.), I'i-. 7). Issl. W au.l Sp. ; Itovi.siim Paln'on-. I'ail 11.. ]i. '-:!.

A small and very .slender species. Calyx ovate, twice n.s long as wide, widest near the middle of the radials, whence it curves gradually and evenly to the end of the basals, and .somewhat more rajjiilly to the arm bases. PJate.s .smooth, without markings, except a small angularity following up and down the median portions of the radials.

Ba.sals formed into a doop, obconieal cup, about as high as wide ; only truncated for the reception of the column, the 'owcr face slightly concave.

IIK.XAt'lllNMD.i:.

778

nniIiiiKs onco and a Imlf n-* loiij,' ms widf, widest nrrosi tlio iniddlo ; the iippoi' liu'OH deeply exciiviiti'd to more tlinii diu- liiill' llio widlliof llio idiiti's. Coslid.t two, olosfly iiticliyloML'd and very Annt, tlioir combiiUMl k-ngtli Ichm tliaii tlicii" widtli; till,' lowLT pliito, and partly tlii) upper, resting; ('(jiiiplcti'ly williin tlio facet, the distal fa(!eH of tlio upper Imt slij,ditly niii,'idar. Distidials tliree; the two lower plates no closely anehylosed that the Mutiire line is t'reiiuently obsolete. The costals ami distiehals, in place of takiii)^' the usual uutwanl eiuve, heud slightly inward, so as to make the width of the specimen directly ahove tlie radials less than the width of the cup. .\ruis twenty (not twelve, us stated iiy Casseday and Ly<Mi), closely folded at their i)roxiuial ends, recurving ahove the .second hifureation. and tiie tips hanging downward, exposing the ainhuhicra. Pinnules long. An.'d [ilato of the same width as the radials, hut the U)wcr margin distinctly angular, and the upper concave; it is followed hy nuui' loiis ^mall plates forming a small, rounded protuber- ance. Position of the amis almost marginid. Column round.

Jlorizon and Lo'nlllij. — Keokuk limestone; Crawfordsvillo, Ind., and Hardin Co., Ky.

T1//1111 in the collection of the late Major Lyon at JefTersonville, Ind.

L'i'iiutrks. — The specimen which Professor Wortheii erroneously figured in the Illinois Geol. liepoil of 1871! under tiiis name has but ten arms, while JJ. firiix has twenty, liesides, it dilTeis ((uilo essentially in the I'orin of the calyx. Curiously enough, Worthen described his specimen as having five radials and six costals, evidently supposing, as Ca.s.seday and Lyon did, that the anal plate sup[)orted two arm.s.

This sp'cies approaches D. iHiuknn in its tendency to pendent nrms; but the latter is larger, the dorsal cup proportionally wider, the base .shorter, and bowl-shaped instead of obconical.

DichOCrinuS pontalobUS (Cass, and T-von). Piik LXXVIII. rirjs. 11a, h, c.

lSf)0. Cotnlntminerhms p<-/ilii/ii'iiis — Cx'^srAtw riiicl I.von ; I'niccnl. .\incr, AfnJ. of Arts and Sci., Vol.

v., p. 2C,. isr,5. (?) ('■ tghiloiinrriiiiin i)''iil<iluljiix — SiM'M.uui; Oiliil. I'.'ilii'nz, Viiss. X. Amer., Y .'iGO. 1S77. (:,h/l,-,fi,iinr,-i,iii< i)-ii/(i/n/,iii — S. A.Mit.i.Kii; (';iliil. Aiiicr. I'.ila'iiz , Fuss., p. 'J2. ISSl. (?) t 'u/i/lf(lo)iod-iiiii.i peii/iilo/iii3 — UpvWmn Tiitirncr., Piirt TI,, p. 7S.

Calyx elongate ; plates thin and without ornamentation. Ba?als largo, forming a sub-ovoid cup with a thickened rim around the lower margin ; bottom but partly occupied by the column. Radials gradually increasing in

770

Tin; (UINOIDKA t AMI'.II.VTA or Noiiril A.MKIIK A.

; I

■I

wiilili, \\iiK>t lit two lliinl'* tla'ir liciijlit ; xliglitly coiifrncti'il m ilu' loji ninl twice iiN long III* tlicii' width iit tliu botloiii; tliu outer Nurfacu ii little convex, mill soiiiewlmt aiitrnliir aioiij,' the nietliim line ; ruectH deepiv eveaviiti'd Id ahiio.it the lull widlli of the jdate, ieaviiij,' a ^li^ht tniiieatioii at each ."ide. Contain and difttiehali two each, united \iy "} zvgy, their eoinhined length ahout ei|Ual to the widih; liotli contaU mid the lower dir^tielud eoiii|detely resting within the radial liicit. Lines of union In .ween the hv|ioz\^'al and e|M/y.i.'al joiiit.i Mtraigiit, liiit those between the eostals and distiehals, and between tiie (listichals and |iidniai'H, decidedly waving and much more distinct. The up|ier laces of the epizygal joiutH proviilud with lougue-liko processes, which enter enrresponding recesses upon the lower I'aees ul' the plates u[ the suceeeiling order. First palmar deeply e.veavateil along the ujiper I'aee, and constituting n part of the calyx ; the succeeding oiien are free nrni plates, and bend ab- ruptly outwnril. Anns twenty, »trong, simple, biserial and pendent, resting by their dorsal surfaces upon the radials and anal plate, which are slightly impressed thereliy. I'imiiiles stout and long; tbcii' aiiibiilaeral furrows wide, and roofed over by small covering plates. N'entnil disk .slightly convex, almost (lat. tlu' amhulacni exposed to view. Four of the interradil have but one ])late in contact with the radials, while the anal plate supports three, the I'uiiiier as well as the latter abutting against the second distichals, but not against the first, nor against the costals. which rest within the radial facet. Anal opening subcentral, pa.ssing through the Hat surface of the di.sk. Column round and small.

If'iri:('ii and Loni/iti/. — KaskasUia group; Grayson Springs, Gray.son Co., Ky., and .Sloans Valley, I'ldaski Co., Ky.

2}/j)cs in the Major Lyon collection, .leffcr.sonvillc, Ind.

licinarks. — A strict enforcement of the rules of nomenclature would, amu'ding to some o[)iiiions, re(|iiire the above speeilic name to bo rejcetcil on account of erroneous composition. After being so long recognized in Hcientific literature we prefer not to clinnge it, — at least not until greater necessity api)ears for doing so.

!»•

IIKXACllIXID.i:

Dioboorlnuii diohotomuR \i.\u..

l"«5n. II\|,I, , Sm|.ii1 (;,..|. I(i|i, |m»,i, p s-, (,|i,i((iniu I'liilc 1. I'lit. 5).

bM. W iihil Sr; Iti'viMnii, I'iilir.irr.. I'ltrl II , |>, M. . '

Aocoidiiij^ to Hull, tlio calyx is hlmllciw oii[i-r(iiin, tlio l)nKnli^ occuiiyin^ ono tliiid In lii'i;;lit. IJailiiil^^ wiiliT than lon^', ilif lower inar>,'in of llif I'acc t fliglilly tliicUi'iifd. C'o.«tals I'xtii'iiii'Iy tlioit and narrow, icciiji^ ing Hoarcciv tlio lil'lli part of tlio widlli <il llic ladials at tliu lo]). Al'liix dicliotoiiii/iii^ twice or oftoiuT. uni^'oiial in the lower portions j comiiosed of eniientc iilate^i, wliieli (gradually inleiiijcU U|nvard. Suilaee of iilatc.-* " ininctale or iimrked l)y f<li;(lit rounded dejiressionn, Hcparaled liy narrow, elevated lines."

IJorhnn anil Local i/i/. — V-'armw limestone, Warnaw, III.

lumar/cs. — Tliis ppocicM wiim descrilied from a eniHlicd fpociineii in llie collection of llic late I'rofex.tor Wortlieii, from which the characters cannot bo mitisliictorily asccrluined.

II

I

^*

Dichocrlnus Humburgi H. \. :\tit,M:ii.

l<ifll. S. A. MiM.ni; (i,"l. Suit. Mi«»iin, Hull. I, p. 2(\, I'liilo 3, I'ij,".. 1) nml in, nml Ailv. Sheds Kill Hep. (Irnl. Siirv. Iniliiiiiii, p, ;!ii, I'liitc (1, Fiu'. .'is.

Descrilied from two HpecimeiiH, which are only preserved to the second piiliiiars, nnd, according to Miller, " show considerable variation in Hize und relative proportions," the radials of the one "only about one half loiij^er than wide," in the other " twice as long as wide." Hasal cup a little less tlum h;df the length of the calyx, obeonical, truncated, and slightly concave nt the botloiii, the cidninn not tilling the lower concavity, the re-entering angles "hardly disct'iiiiMe on either side." Kadials expanding byt little. the facets oceiiii)ing nearly the entire width of the plates, ("ostals "one," thill and axillary. Distichals two. Arms twenty, uniserial so far as observed. Anal plate a very little smaller than the radials, the upper end contracting. Surface of plates smooth.

Ilurizoii and LiivaHtij. — Lower part of Warsaw limestone ; Boonville, Mo.

7//p in the eidlection of Mr. R. A. lUiiir, of Sedalia, Mo.

L'oniirl,!^. — The two specimens alluded to aliove not only differ in the proportions of the plates, but also the reentering angles meeting the basi- radial suture, which in the one were .«aiJ to be " hardly discernible," are in the other, according to figure, imusually deep. The speciinen.j evidently

778 TIIK CniXOIDKA CAMKRATA OF NOKTII AMKHICA.

have two costals, as all other D'lclwcrbu, and Miller overlooked the syzjgial suture, which is often quite obscure in this genus. This form should bo compared with D.Jiciis, with which it is probably synonymous.

Dichocrinus parvulus s. A. jiilleh.

1S91. S. A. .MiLl.tii; Clool. Siirv. Missouri, UuU. t, p. 27, I'liitc 4, Figs. 7, 3.

Caly.\ small. Dorsal cup higher than wide, somewhat obconi ^al ; sutures slightly depressed, giving a little convexity to the plates; surface granular. Biisuls forming a short obconical cup, twice as wide as high, pointed to the small colunm below ; the re-entering angles toward the basi-radial suture deeper at the posterior side than at the anterior. Eadials one half longer than wide; their width increasing upwards; the facet broad and but slightly excavated. Costals one — according to Miller, but probably two — a little wider than long, and occupying three fourths of the width of the radials. Arms ten, rounded on the back, and composed of a single series of short cuneate pieces. Pinnules heavy and closely packed. Anal plate a little narrower than the radials. Cohunn round.

Ilurcon and LocaU/y. — Lower part of AVarsaw limestone; Boonville, Mo.

2'i/j>c in the collection of Mr. R. A. Blair, Sedalia.

li

1 1

1

DichOCrinus Blairi S. A. Miller. Plate LXXr. Fig. 3.

1^91. S. A. Miller ; .Vdv. Sheets 17th Hop. Geol. Surv. Iiuliaim, p. Sfi, Phitc 8, FIr. 12.

Calyx short, obconoidtd or hubtnrbinatc; plates thin; surface granular. Basal cup a little more than one third the length of the calyx to the top of the radials ; the re-entering angles rather deep. Badials slightly ex- panding-, twice as long as wide, longitudinally convex, and projecting at the facets, which occupy half the width of the plates, and slope downward. Costals two, supporting 2X2 distichals, which apparently are free from the costal axillary. Arms four to the ra}-, large, long, and composed of a single series of short, cinieiform pieces. Pinnules long and heavy. Column round, composed of short pieces; the nodal ones somewhat projecting.

IIor!.;oii and Locdllly. — Same as last.

Ti/pc in the collection of Mr. R. A. Blair.

liaiuulis, — The calyx of the type specimen is much flattened, and it is

IIEXACRIXII).!;.

771)

dilTicult to make comparison with allicil foniis. The descriptions of thi.s and tlie two preceiling species are made after Miller, we having no authentic specimens for comparison.

CAMPTOCRINUS W. ami Sr. (MOV. siil.gcn.). (xa/iTrros Ijliailt, k(u'ioi' a lilj'.)

In the construction of the calyx and arms identical with Dlchocrhms, but differing in the structure of the stem, wliicii in all the .siiecimcns in which we observed it is curled around the crown. The .«tem joints are circular near the calyx, but at some distance off gradually turn into crescent-shaped, and the two horns of the crescent give off long, stout, and pliant cirri IVom every joint. The stem coils to the concave side.

The structure of this stem reminds us of Hall's genus ^f//clo(h(cti/liis * of the Niagara group; and similar stems occur in the Wenlock limestone of Dudley, England, and Gotland, Sweden, which have been referred by Angelin, and also by Bather, to the inadunate genus Uirjiclocrinus Salter, a genus with close allinities to Ilitcrocrlnus. Such stems are also found among the Potcriocriiiiikv of the Kaskaskia group, showing that they occur not only at various horizons, but also in very dilTercnt groups ; and we doubt if this structure is of much importance for classilication. We therefore place Caiiip- tovriniis Rubgenorically under Dlc/iocriiius.

DiKtrihidhn. — Found from the Keokuk limestone to the Kaskaskia group, and apparently restricted to America.

7,'^2)C. — Camplocriinis mydodadijhts.

Camptocrinus myelodactylus w. ami Si>. (nov. spec).

riak LXXV. Fhjx. 1, 2a, h.

A small species with curving stem and long paired cirri, which are given off in longitudin..'. rows on the concave side, as in Hall's Mi/dodaclyhis. Calyx elongate, slightly spreading ; the plates smooth ; the suture lines indistinct. Base one third the height of the dor.sal cup, its sides convex. Radials twice as long as wide ; the facets not excavated, and the costals resting upon the straight upper faces, occupying throe fourths their width. Costals two, very short ; the second obtusely angular above. Arms two to the ray, in close contact laterally, twice and a half as long as the calyx, and composed of • PaliEout. N. York, Vol. II., ik 233, Piute \i, Figs. 5, G, and Pliitc 45, Figs. 7, 8, 9.

7S0

THE CRIXOIDEA CAMERATA OF NORTH AMERICA.

rather long quatliangular pieces. Pinnules long. Anal plate in size anil form resembling the radials. Anus and ventral disk not visible in the specimens.

Column near the calyx straight, but at 5 mm. from the calyx it curves abruptly back upon the crown, then it enlarges, and by a reverse curve coils upon itself and the included calyx and arms, giving off from alternate joints at the concave side two rows of long cirri, which .sometimes completely envelope and conci'al the crown. Near the calyx, the stem joints are short and circular, but they gradually grow longer and crescent-shaped, their width increasing from 2 to 3 mm. The cirri arc very long and stout at their proximal ends, but terminate in a sharp point. They arc composed of about sixteen to eighteen joints, which arc as wide as long, and radiate from the centre of the .spiral curvature of the stem.

Hiinzon and Locality. — Keokuk group ; Indian creek, Montgomery Co., Ind.

Types in the collection of Wachsmuth and Springer.

Camptocrinus cirrifer w. .ind Sp. (nov. spec). Plate LXXVI. FIffs. 13a, b, c.

In its general aspect closely resembling the preceding species, the calyx, however, shorter, especially the basal part, which occupies only one third the length of the dorsal cup, being but slightly convex at the bottom, and rather deeply depressed in the centre for the reception of the column. Eadi- als once and a half as long as wide, the sides nearly parallel, the upper faces slightly excavated to one halt their width. Costals two, very short, the intervening sr^ure lines obscure; the first linear, the second subtrigonal, its sloping iipper 'aces at right angles. Arms two to the ray, simple, slender, divergent, thread-like in the upper portions, and composed of long, quadran- gular joints. Pinnules of moderate length and not in contact. All plates perfectly smooth. Structure of ventral disk and anus unknown.

The column is narrow in the up])er portions, but gradually increases in width downward, until at an inch and a half from the basals it is twice as wide as at the top. Close to the calyx it bonds abruptly upward to a level with tlie top of the radials, then reversing it curves downward, either gently to the end, or — more generally — forming a coil around the crown. The stem joints are short and circular near the calyx, hut soon grow longer, and the section becomes oval and gradually crescent-shaped with the concave

IlEXACRINIDvE.

7S1

side inward. Both liorns of the croscont give olTE cirri from nUer.intc plutcs, communicating with tlie axial canal of the stem, which is oval, its long dia- meter at right angles to the curvature of the column. There are no cirri in the upper part of the stem ; {\wy commence at some distance from the calyx, and are restricted to the convoluted part. In specimens with a closely coiled stem, tiio ends of the cirri meet in the centre, and resemble the spokes of a wheel ; they are stout at the proximal end and extremely long, being com- po.scd of thirty or more pieces, of which the five proximal ones are longer than wide, the upper somewhat shorter.

Iforkoii ami LocaJitij. — Kaskaskia group, near Sloans Valley, Pulaski Co., Ky.

Typca in the collecti(m of Wachsmuth and Springer.

TALAROCRINUS AV. ai.,1 Sp.

ISSl. W. nml Si'. ; IJiivisiiiii TuIic lor., P.iit 11., |v S,j (IVicrrd. Arul. X:it. Sci. riiiln., p 250). l^<\. S. .\. MiT.i.i.K! Ciiliil. .\iMir. I'liluM/.. Fciss. (Sicdud Kilil.), 'JSS.

lS^j. W. luul Si'.; Kcvisi.iii I'lil.i'Hcr, hut III , p. 120 (I'rticci'il. Aciid. Nat. Sci. riiilii., p. 313), ISSa. S. A. Mii.i.Kii; X. Amcr. (Icdl. mid I'ldicdul., p. 2--,).

Sj'ii. IHrhorriiiiii (in part) — Sin MMUi; Tiaiis. St. Lniiis Arad. Sci., Vid. I., p. 71.

Svii. Dii'/iocriiins (ill part) — Ciss. and Lvon ; Vrncfi'd. Aiiii'r. Arad. .\rts and Sci., pp. 10-23.

Sj-ii. rtrrutocriiiiis (iu pail) — S. A. .\lii.i.Kii ; Catal. Amcr. I'alii'uz. Foss. (First Kdit.), p. S'J.

Specimens small. Calyx, as a rule, higher than wide ; the ventral disk as high as the dorsal cup ; the plates thick and devoid of ornamentation.

Basals two, of equal size and similar form, the suture between them passing from the tmal plate to tiie anterior radiid ; they form together ii shallow cu]), which is more or less tran.sversely elongate, and somewhat excavated at the bottom ; tlie superior margin of the cup octagonal, six angles being salient and two retreating, the latter directed to the sides which correspond to the longer ditimeter of the ba.se.

Radials five, enclosing an anal plate of the same size or even larger; fi)ur of them having .slightly convex lower faces ; while the anterior one is angular below. The upper faces are somewhat excavated in the middle, and trun- cated at the outer ends. Costals one, very smtdl, often completely hidden IVom view by the distichals ; when visible, triangular in outline. Distichtds one or two, small ; their lower faces resting obliquely against the costals ; tlieir sides touching the radials. The third order of brachials supports the free arms, of which there are four to the ray. The arms, so far as observed, are simple and biscrial.

I

782

THE CRIXOIDEA CAMERATA OK NOKTII A.AIEUICA.

Inturradiiils one or tlircc in tlie first row, followed by one or two in the second, all forming a part of the ventral disk. The largo anid plate of the dorsal cup is generally followed at the tcginen by two rows of three plates each, and these by a large number of minute pieces, which enclose the anus. The anal opening is directed laterally and placed near the upper end of the anal area. The posterior oral occupies a central — or nearly central — posi- tion ; it is highly protuberant, and very large compared with the other four, which arc small, scarcely convex, and ])ushed to the anterior side ; but sometimes they ma}" be unrepresented altogether. In this case, small cover- ing pieces follow the sides of the posterior oral ; but when all the orals arc represented, generally largo radial dome plates of a first and second order take the place of the covering plates.

Colmnn round, small; axial canal minute.

Dint rihiit it'll. — Probably restricted to the age of the Warsaw and St. Louis groups.

T^/jic of the genus: TalarorrhniH coruii/criifi (Shumard). licinar/i-s. — Tnhtrorrliuis forms a transition Ijctwecn Didwcrinm and Phro- focriiiifs. It preceded J'/cro/ocriitiis in geological time, while Dic/iocriiiii'!, although surviving Tidurocrinus, reached its climax before the latter was introduced. The species U|)on which the genus was founded were originally described by Slannard and Casseday and Lyon under DkhocriiuiK, whence S. A. Miller removed them to Ptcro/vcrlniis.

Tiihirommts difTers from Dir/iocn'niis in the more massive plates, and in having but one costal to the ray. The latter is the case also in Ptcrotocrimis, but the distichals in that genus are comparatively large, and form an import- ant part of the calyx ; while those of I'li/iiriirrliii'S are small, and retain the form of free arm plates. Besides, Pliratocr'nuis has large, wing-like ai)pendages fastoned to the surface of the test, like which nothing is foimd in Talnro- rriiiKS ; the corresponding plates of the latter are much sr'.dler and are inserted between the other plates, instead of resting against their be\ led outer edges.

A.

i

m

llEXACRINID^E. 7S3

Talarocrinus oornigeruB (Sntsi.). Plate LXXVIII. Fiij^. Ga, h, and 7a, h.

1858. Dii-hrriiiiia coriiii/mis — Smawiu; Tnins. St. Louis AciiJ. Sri., Vol. I., p. 7i, riato 1, Figs.

hi-(l. ISO,'. Pfm/oi'i-iiiiis roniiyrrus — SinniAun; C'nliil. Palicoz. Foss. N. Aincr., p. 39:i. 1877. I'/entMriiittn rur/ii'i/mis — S. A. Mii.lkii; Ciiliil. Ainci. r.iliuoz. Foss. (1st Kdit.), p. S9. 18S1. Tiiliiron-iiiKH coniir/friis — \V. iiiiil Si'.; R.-visinu I'lilu'ocr., I'lU't 11., p, '•7. 1S83. 2'iiliinrri/iiis coniy'-riis — S. A. Mii.i.Kli ; C;iliil. Amei-. Fala'c)/.. Foss. (l'(1 Edit.), p. 2S8.

Ciilj'X ovato, the bn-ic sliylitly truncated iiiid cxcavntcd at the bottom. Dorsal cup a little lower tlian the ventral disk, and .soniewliat shorter than wide; the plates strong, moderately convex, but without other markings; suture lines distinctly grooved.

Basiils forming a shallow cup, which is transversely elongated, and occu- pies about one tliird the liL'ight of the dorsal cup ; it is concave at the lower face, and the cavity is only partly filled by the column. Kadials sub- quadrangular, slightly increasing in width upward, their length equal to the greatest width ; the plates arc a little tumid, the greatest convexity being at two thirds their height, whence they .slope considerably to the upper margin, producing a moderate depression or constriction beneath the arm regions. Anal plate considerably longer than the radials, its upper face on a level with the top of the distichals, its lower face angular, the lateral faces parallel. Costals and distichals very small, the former trigonttl, often not visible externally, and the distichals appear as if they rested upon the radials, as described by Shumard ; they bend slightly outward, and are wider than high, their upper faces concave, forming a sharp angle. First palmars narrower and shorter than the distichals, rounded like arm plates ; the two outer ones touching the radials. Arm openings four to the ray. The arms are not preserved in any of the specimens. Ventral di.sk highly elevated and bulging ; the interambulacral spaces depressed, and the plates flat. The radial dome plates strongly tuberculous, the other disk plates con- vex. Posterior oral strictly central and of extreme size, forming a large ovato tubercle, the shorter diameter facing the posterior and anterior sides. The other orals quite small and scarcely convex. Four of the interambulacral spaces narrow, and the plates elongate; arranged 1, 2, 2, with sometimes one or two small accessory pieces interposed between them. The posterior interradius is wide, being composed above the anal plate

784

TIIK CKINOIUKA CAMKRATA OK NOKTU AMKUICA.

of four or (Ivo inoilerutc sized pliitc-', followed by n very liivgo miniber of small pieeeM, foniriig nn elongate, convex area, wliieli rises from tlie largo nnal plate, nnd extends to the posterior oral, being siu'rounded on all sides by a sliallow groove. The plates of the area, although irregular in form, arc arranged with a certain regul.'.rity, and the lower ones arc con- giderably larger than those surromuling the anal opening, wliieh are very minute. The nnu.s is located in the upper part of the area, and opens out laterally. Column .«mall and round.

ILtrhm and Locaflti/. — Upper part of St. Louis group ; Fran'vlin Co., Ala., and Tateville, Pulaski Co., Ky.

Ti/jic in the Shumard collection at the Museum of Washington University, St. Louis.

Talarocrinus sexlobatus (.'^m m.). Plate LXXVIII. Fnjs. ;■!, h, c.

ISJC). Dichocrinuf sej-lu'/ii/iix — SiiuMMin; Tniiis. St. l.iniis Acail. Sci., Vol. I., p. 73, I'igs. 3, 3a-e,

I'^fij. P/rrol'ifriiiii.i si-x/ii'mi/iis — ^'Uysiww, Catiil. I'lilii'n/,. Fuss. N. .\mrr. p. 3!)i.

ISfi;. l'/,;-u/'jcriiiiis srxh/M/ii' — S. A. .Mir.Miir, C'al.'il. AiiiiT. I'ala'nz. Fuss. ()st Kilit ). p. SO.

18SI. Tiiliirorriims scxlu/,iif,is — \V. anil Si\ ; Ki'visimi I'ahv.icr., I'ai't 1 1., p. S7.

18S3. Tiihirocriiiiis scxlubuliii — i*. A. Mll.l.Kii ; Catal. Aiiur. Palanz. Fuss. (2(1 Eilit.), p. 2SS.

Calyx a little higher than wide, constricted at the arm regions, and Furmounted by five short heavy .spines. Dorsal cup more depressed tlian in the preceding species, the plates more rapidly sin-eading and more tmuid, making the outline of the cup, as seen from below, (piite distinctly six-lobed. The plates devoid of ornamentation.

Ba.sal cup shallow, its heiglit from a side view less than one fourth the length of tlie radials; tiie salient angles at the upper margin very obtuse, ns are also the re-entering angles toward the anal plate and anterior radial; the centre .^lightly excavated for the reception of the column. Hailials about as wide as long, widest at two thirds theii height, very thick and tumid in the middle ; their greatest convexity is near the ui)per end, whence they slope rapidly to the arm bases, forming a rounded, transverse node. The lower faces in four of the radials are straight, or nearly so, in the anterior one obtusely angular; all the superior faces are deeply excavated, and their outer ends project somewhat like the limits of the radials in Blastoids. The anal plate is longer than the radials. and, like them, tunud near the top nnd widest across the middle. Costals very small, not visible externally, being perfectly covered by the distiehals. Distiehals comparatively large, resting

-f •

i\

IIKXACRINID.E.

785

completely within the radial facets; wider thnn long, shnrply angular at the top, their sloping upper faces concave. Arms four to the ray, their structure unknown. Ventral disk liiglily elevated, resting upon the inflected upper ends of the radials and anal plate, and hence narrower than the dorsal cup; the sides almost vertical, and the sunnnit Hat. The posterior oral, which is subcentral, is large and strongly convex, tiio four others considerably nar- rower and almost flat ; the outer ends of tlie latter curve abruptly down- wanl, and take part in the sides of the disk. Tiie radial dome plates rest at right angles between two orals; they are quite large, and are extended into short, heavy obliquely directed spines. The first range of interradials consists of three pieces, of which the two outer ones are very narrow and do not touch the radials; they are followed by two small interambulacrals, and these by the orals. The anal plate supports upon its truncate upper face a rather large quadrangular piece, and upon its upper slopii faces an elon- gate narrow one, followed by other rows of three plates of smaller size, and by a moderate number of other pieces, which form a small protuberance containing the anus. Anal opening on a level with the posterior radial dome plates.

Il>ri::on and Loral'ttij. — Upper part of St. Louis group; Russell ville, Ky.; Logan Co., Ky., and Fiagpont, Va.

The tijpe specimen, formerly in Dr. Shnmard's collection, could not be found in the Museum of Washington University at St. Louis, and is probably lost. The specimens figured are from the collection of Wachsmuth and Springer.

Eonarls, — This species is readily distmgnished from T. cornujerus by the greater depression and tumidity of the dorsal cup, the constriction at the arm bases, tiie erect form of the disk, the narrowness of the anal interradius, and the comparatively small number of disk plates.

780

TIIK tUlXOIDKA CAMKUAIA Ol' NDIMII AMKIUCA.

Talaroorinua symmetricua Cas". nml Lvov. Plate LXX Vflf. Fir/a. 4a, h, ami -7.

ISnO. /lir/iurriiiHii nyiimelriciif — CAssi.nw ninl TiV(i\ ; I'mcri'il. .nrr. Ariid. Ails ami Sci., Viil. V., p. i\.

ISftli I)i,-lin,-riiiiiA ri/iiiiiirtri,-ii.i — SiiiMMin; Ciil.il. I'.ilimz, Kn- . N. AiiiiT., |i. .'1117.

1S77. lticho,-riiiii» >i)iiimelni'ii> — S. A. >lii,r.iii; Ciiliil. I'lilnn/.. Fuss. Anicr. (1st Kdil.), p. 76.

1S31. Talitrufriiiiis syuimi'/rieii.' — W. niiil ^^l'. i lti'\\>inii Talii r., I'lii't II., p. S",

18S3. Tiihrocriiiiii >;/mnirlri,-iif—H. A. Mll.I.FIi; Ciil.'il. Till. l''n»s. Aiiicr. (lM I'Mii.), p. 2SS,

8\ii. /lii'iiu'i-iiiii) cliyiiiif — Lvos niul ('\ss.j I'mriTil. Aiiicr. Acml. Arls iiiiil Sci., Vdl. V., p. 22.

Sya. T'lliiiwriiiaa cUyuns — \V. niul Sr. J Itrvisimi ]':ihi'cirr., J'arl II., p. '-7.

This .><peeie9 is closely nllicd to tlic proci'diiiir one, liiit somcwlmt sinnllcr; tho (lor.'ial cup is more doprcxscd, the form of tlio vuiitml disk more conical. Ics.s contrncted at tho periphery, mid tlie anal nreii wider. Dorsal cup semi- glohose, slightly lobod ns seen from above or below, tho plates without ornamentation ; suture lines distinctly giooved.

Basal cup quite shallow, widest at right angles to the interhasal suture. Radials .spreading rapidly to the middle, le.ss rapidly in tho upper portions; the superior faces a little excavated, and their outer edges slightly truncated. Anal plate longer than the radials, widest in the middle, the upper end inilected, making the lateral faces convex. Costals nnd distichals very small ; not exposed upon the surface ; they are hidden by the two inner palmars of the first row, which ovcrla|) them. The two outer palmars of the first row rest upon the radials, their lateral faces support an interbrachial, which also slightly touches tho rndials. Palmars four in the calyx, in contact later- ally, short and rather deeply e.xcavated for the reception of tho higher brachials, which are not preserved in the specimens. The arms of the same ray are equidistant, while those of dilferent rays are farther apart and sepa- rated by a shallow groove. Ventral disk higher than the dorsal cup. Tho interambulacral spaces filled by one nnd two narrow plates follcv,ed by tho orals ; tho first radial dome plate is conical. The large anal plate supports tiiree plates, of which the middle one is considerably wider than high and somewhat depressed, the two others (piite narrow. The second row also con- sists of three pieces, and these are succc .'ded by numerous smaller ones, which form an elongate roimded lidge containing tho anus. This ridge, which is bounded laterally by a .shallow groove, extends to tho posterior oral in an almost vertical line. The primary radial dome plates alternate with the orals ; they are large and either spinous or strongly tuberculous. The secondary radial dome plates are elongate and enclose a largo interdistichal.

^

r

1-

IIKXACUINID.E.

787

Jliin'ivn and LucaUhj. — Uppor part of St, Louis liiiiuHtoiic ; Gni)>oii, PMinoiidson, iiiid I'uliiski Cos., Ky,

JuiiiKr/i^. — Tliu iy[)o «i)uciiiic'n, wliicli i.s liyiirud on I'liito LXXVIII., Fig. 5, is in tliu Lyon culioctiun ; tiuit of Figs. 4<(, 0 on tlio miniu pluto i.s in the collection of Waclisnmth anil Springer.

Diihumnus de(j<tm Cii^H. and L3on, in our opinion, belongs to this species. Tiii^ type specimen, wliicli is badly crushed, is po.ssibly u little more lobid at the ventral disk, but that alone is not sullicient to make it a (lilYerent species. The differences to which the authors refer are not borne out by the facts. Tiilurnrruuis ti)/)innctr!ci(f>, like T. dvyms, has four arms to the ray, and not two, as stated in the description.

TalarocriDus ovatus WoisTurN riiilc LXX VIII. Fl'j... 2a, h.

1892. AVoiiTilKNi Bulk-till I., 'liiiKiis SInIc Miis. N:il. Ilisl., p. 30.

1>>SI). AVullTMKNi (iw.l llup. llliiiuis, Vol. VII., p. .'tl t. I'liilu ii',1, l'\'. U.

1S8.'). W. anil Si-. ■ itcvisiou I'lilivdcr., I'lirl 111., |i. UO.

Calyx more elongate than in the preceding species, ovate in its general outline, the dorsal cup proportionately higher and less spreading, the radials more evenly convex, and not tumid at the upper end. Basal cup compara- tively large and deep, truncate at the bottom, and slightly excavated for the reception of the column; the sides but little expanding. IJadials somewhat longer than wiilc, a little wider aljove than below, .slightly inllected at the upper end ; their lower faces .straight, except at the anterior plate where they are distinctly angidar ; the upper deeply excavated to about one half their width, and the facet directed obliquely outward. Anal plate longer than the radials and heplagonal. The costals rest oblifjuely upon the radials, and are larger than usual in tliif genu.s, forming a small triangle with con- cave sides. Of the distichals only one row of plates is visible, which arc short and excavated at the upfjcr face. Tiiis may have been followed by an axillary distichal, or have directly supported the arms. The number and structm-e of the arm.? unknown. Ventral di.>:k highly elevated, the intcraiubulacral spaces depressed, especially near the arm bases. Anal area projecting, giving to the ventral disk, as seen from the -^unnnit, a distinctly hexagonal outline. Interradial plates three and one ; the middle plate of the first range, and the upper, very large, the two at the sides small, about half as long as the middle one and considerably narrower. Anal area clou-

t

'i

788

TIIK CKINOIDKA CA.MKHATA OV NOIMII A.MKKU A,

giito convex 1111(1 lioiilert'il !)_)• II giDovi'; it Iiiim tlnee nulici' liirgi' platus in tiio lirst row, iiiid tiiroo in tin- hocoii'I, roilowud \ty ii niuilenitu iimiiljor of winalli'r pioci's; tlio opening is iliiectoil obliiiiiely upwind. Posterior oral twico tlio Hiz.0 of tlio other four and i<pinoii.s, while the latter are uliglilly convex. radial doiiie plate.s large and tiihereuiouH. ''''• , arrangement of tlie other di.sli phites is Himiiar to that of tiie pieeeiliiig .speeie.s.

lliir'aim und Luculiti/. — ('.') Kaskaskia group; Monroe Co., III.1.

Tiie (1//11: aiu", only known .speeinien is in the llIinoiM State collection.

Iii:iii(ivln. — Professor Worthen gives the horizon of this Hpecies hh •' Chester liinesloiu-," which piohalily should he changed \\\U\ upper \wvi ol St. Louis group. Wo infer this from the preservation of the upecimen, and the fact that all the other .species como from that horizon.

TalarocrinuB deoornis w. ^unl Sr. (mov, siicc). riute nXXVIII. Fi<jx. 3ii. />, c.

(?) Syii. r)i-ho.-riii«i eoii»lri-lii> M. ;iiul \V; M',0, (I.. 1. Ii, p. 111>., p, Jfiri, Vol. II . Hate 10, FiRs. 2i/, b, c

Siiiidler than any of the preceding .species. Calyx once and a half as wide as high, eliiiitical in outline, the aim bases jirojecting, the interradial spaces depressed. Dorsal cup iiigher than the ventral disk; the plates con- vex and without ornamentation ; suture lines slightly grooved.

Basiils large, foriuing a rounded cup. which, viewed in i)rofile, has about half the height of the radials; lower face of the cup a little concave, lladials erect, a shade wider at the top than at the bottom, about as wide as long; their lower faces nearly straight, the upper excavated to one half their width at the middle, and the outer ends distinctly truncate<l for the reception of a small iiiterbrachial. Anal plate a little longer than the anterior radial, the upper eiiil somewhat inflected so as to form a widl defined (l(|iressioii at the upper end. Distichals two; the lower one quite short, re-^ting completely within the radial facets, and not coining in contact with the iiiterbrachial plate. Second distichals much larger, sharply angular above, and directed slightly outward. The first palmars take part in the calyx; the others are iVee. Arms four to the ray, biserial above the third or fourth jilate; they are rather stout, rounded on the back, and composed of moderately long, slightly convex pieces, which interlock by a zigzag suture lino. Ventral disk liighly convex; the summit surmounted iiy an immense nodose jilate. Tntor- ambulacral spaces narrow, deeply depressed, having a single elongate plate

T

lIKXACHIMD.r..

780

ill tlio first row, wliieli is followed liy n Mtiinllcr one. TIic nnnl intfrriuliiin, which is iiitii'li tho widust, 1ms oiu' [ihito in tire two [iroxiiiml rows, I'oUowi'il \>y siimll piuces foriiiing a littlo pioliihcruiico aroiiiul tho nmw. Onils n-pic- wonted ]ty a siii^Io [licco, from tin- sidi-s of whicii tlie covcriii;^' iiliitcs of tho ainhiihiPiii puss out to tln' miiis ; thu pinto is liit,dily coiivi'X or nodoso, nnd us iiii'j^o ns the fivo ornls in otJK'r spocies. Aiiibuliicra projfctiii}^, tho cover- iiif? pintos consisting; of two iowh of »tnmll pieces, which iiro nltorniitcly urnui^^i'd ; they hifiiiciid' on ii riitlior Inrgo nxiliiiry, and tho two lirnnchos are sopiiratod l>y a lnr;;o intordistichid.

Jlorixon (iiiil Luntli/i/. — Upper part of St. Louis group ; Tate\illi', Pida^lu Co., Ky.

Ti/iiin ill tho collection of Wachsmnth nnd Springer,

livinnrkK. — This spe(;ies is reinarkalile for having 'jut a single oral plate ; tho other four orals are either undeveloped, or, more prohahly, were resorhed ill tho growing criiiuid. Another pecnliarity of this species is tho uhsenco of spines, and the presence of regular covering pieces in tho disk.

JleeU and Worthen's Dlclinrriiuin ciiiftrlrtnn may possildy ho identieid with this species, but as only tho busuls and radiuls are known no satis- factory comparison can ho made.

Talarocrinus subglobosus w. and sp. (nov si^c). r/ato LXX/X. Fl.js. hi, h.

A small species. Calyx proportionidly shorter than in T. dccornh, and snbglohoso instead of ovate; tho interradial spaces depressed at the arm regions; plates of the dorsal cup ronmleil and a little conve.x; suture lines somewhat grooved.

Basal cup small and quite shallow ; widest at right angles to tho suture line; tho lower face slightly excavateil. Radials about as wide as long, rapidly spreading from the base upward, tumid, nnd a little inllected at tho upper part ; radial facets broadly excavated, and the limbs slightly trnnrnted for tho reception of tho interbrachials. Anal plate larger than tho radials and considerably widest across the miildle. Costals (|uite large for the genus, filling almost the entire width of tho facets in whicli the}' rest. Distichnls 2X2, short, those of tho first range .slightly touching tho radials, and all, together with tho costals, facing outward. Anns four to tho ray, free above the distichals. Ventral disk subpyramidal, a little shorter than the dorsal

rito

llli; < I(INU||I|;.V ( AMI.IIAIA (II' MMilll A.MI.ltK A.

cuji; till.' iiitiTi'iiiliiil h|iiu'('M (l('|>i'i'«!<('il mill wilier llmii iiniitil in llii.i giMUin; tlii-y iiio t'om|io,-<i'il of lour jilutos, nf wliirli the tlnoo of llii' (iret row rent iilioii till! niiliiil'*, llicir xiiK'.s luiuliiii}; llio ili>tii'lml.'<, tliu utlicr lieing much Iarj{i'r mill iiili'i[ii),«r(l lifiwccii lliu nuliul ilmiH' |i1iiIi'm. OmU vi-r^' irregular ill tlii-'ir iirrmii^i'iiii'iil ; tlu' posicrior oiio i-trirlly ccntiiil, wry l.irge uiul ^<l>illl)ll■' ; till' iillii'is iK'uii}' llat, tin; |iu>itii>ii ol' ilic iiiitorinr one ^tljt'tl_)• iiitiT- railial, wliilo tlmt of the two miti'ro-lati nil oiit'i iiii|i('arj< to bo iiIiiiomI railial. Till' cii.i'riiig jru'ci'i I'lilor llio I'alvx al'lrr tin' lir.it iliNinioii of llio aiiiliulaora, ami till- two liraiicla'.t are MOparateil \ty a ralliiT larj,'!- platt'. The anal opi'ii- iiig t)PtMi|iifs till' ii|)|u'r part of a wi'll di'lliii'il iirotulporaiu'i', a sort of rtniinli'il viTtioal riiljfL', wliii'li uxti'iuls froiu tlio K|)ei'ial anal jilato to tlie ^)o^*t^.■rior oral, anil i^ Hiirrouiidt'il \>y a lU'i'p groove.

J/i'ri.ioii tiiiil Liiridi/i/. — I'lipLT jtart of tlii' St. Louis group, at Tatoville, Pula-ki Co., Ky.. assoriaii'il with tin- pri-ci'ilinj.' spi'i'ii's,

T^/jiai ill tlio collection oi" \Vaeli."*inutli ami .Springer.

TalarocriniiB aimplox (Smim.).

i'/.,t, i.xxviii. rh/s.s„, h.

I^,"i7. Hi.-i'irriiiHi tiiii/i/'-r — SiiiMMUi; Tniis. SI. I.iiuis Ai'iul. Sci., |i. ' i, I'liilo 1, Fit'i. ;'.(. i. IS.-.s. /ii,'t,„viiiii.r fii.i/i/.'X — Ihi.i.; (iiol \W\K lu»a. Vul. I., I'iirl II., \i (ijt, riutt' iii, Kit,'!". IJ.i, «. l^Si. l)i:-liiii-riiiHn iiiiiiil''x — W. niul Sr. ; llcvisiuii I'liln'ncr., Part II., p. Si.

A .■iiiiall spi'cic'.-i, tliu wiiltli of tlio calyx varying from 5 to 0 mm. Dor.sil cup generally a little higher than wiile, wiile.st at the ha.'^i-railial .xiituro or a little ahovr, .•<i)iiii'wliiit c_\ liinlrii-.I along the median portions, and gradually loiilracting towanl the arm ha.ses. I'lates thick, and without ornamentation or other markings; suture lines distinct, hut not grooved.

15asal cui) large, semiglohose, extending to fully one half the height of the calyx ; the lower end slightly llatteiud. the central part excavated, I'orining a narrow circular pit of considerahle depth ; the salient angles at the upper margin ipiite ohtuso, the re-entering angles toward the anal plato and anterior radial conqiaratively shaii>. IJadials slightly dilTering in form, some i)eiiig wider than others, luit all, as a rule, longer than wide ami narrowest at the top. The .superior faces of the plates are directed ol»lii|uely inward, and the ends are but slightly truncated ; they are excavated to one half their width by the facets which contain the coslals and distichals. Anal plate generally wider at the bottom than the radials, but narrower at the top.

>.

iii;xA(RiMi>.i;.

''I

Conlnl* very niiimtc. I)i;.ficIinlH I X 10 in flio rnlyx; of flio oaiiio piopDifiDii'* (iH tlio ovi'rlyiiiK '"'" iilnti". Ahih niiimii'iitly liii, ilu'ir Mtnicttiru iiml tlint ol'llii' vciitnil (link iiiikiiiiNvti,

ll>ii.i>i\ iiiiil l.iiiiilili/. — WiiiHiiw llmcwfoiii', Kciiiiiil lit S|i('i'p'ii Hill. IihI,, Coni'vicvo Co., Mo., iiml in iimiiy iiIiu'ch in Ktiiliuky iiihI Tciiiii'^i't'.

Iiiii»irl,».-'V\iU Hpocii's liiiN hiiii liorotoforu icri'iinl in Ifiili'irn'mi.t, willi wliich, no (lonlif, it hnn Honic iiHinitit.'H ; tlio in'cwfiifi', liowuviT, of n i»inj{Io voi'v niiinito I'tHtiil, ili(> I'oini iiml arnin^cnicnt of tlic ili'^licliiilH in>il .xurct't'il- ing linicliiiiN, mIihw ilisiinclly its closo ri'lulion.H wiili 'I'lilniurriniix. Tli" (•pc'cinnMH vary consicitTiiliIy in si/o ami •^unu'wliiil in I'dini ; in im -I n| flu'iu the .xiili's (if liio fiilyx arc i-vcnly rianidi'il. uhilc in otlu'iH tlicy are cnnfrni'tt'fl alini'i the liasi-radial .-nfnri-. Mn'k ami Wmilicn di'^iciilicd a (tpuoiincn of tliix kind ax ii ili.»tint't mjiocIi'm nndiT tiic naino />. innslriititH.

PTER0T0CRINU8 I n-n hM Cam.

I'.V). t.vnx mill CxNi.; Anii-r. ,1 i. S,i., Vul "XIX., p. M.

ISIill. Mkkk iiimI WiiliniKN; lii'ul. Iti'|> llliuniH, 'il. ||„ p. ;><tS.

Itim. Sim MAiMi; 'rniiis. Si. L.mln .\iiul. Spi., V '. It., p. lUt.

1S7!), Wniii iiiiv 1 .liiiini. Ciiiriii. ,"<ii|.. Nui. 111-'., Vol. II. 'April iiiiii ' ir).

!">*'.•. Wkiiihiiiv; M/V. (I Ii'IhIkt iiiinilici).

\^Vi. /.UTKI.; lluMilli ili'i' I'mIiioiiI , Vul. I., p. an.'i.

l^^l. \\. iiM.l Sr. J l|riiM,,ii |\iliii,cr,, I'lirt II , p s7.

1>H-,. W. ■.m\ Sp. ; ,l,i.l.. I'ail III,, p. \H).

ISMJ. S, \. .MiM.KIi; N. .\iiuT. V,mWy mill I'lilinnil., p. r,(\.

Smi. .lsi,,:irri.iH> I.viiv (m.i Miiii-i, i- |s:;;i); (I,.. I. II. p. Ki'iiliii'l>,v, V..1.

p. 17.'.

Calyx nioiv or K-sx tnrliinalc; llio plali'M lioiivy nnd \.iili(Mit ornivion. lation. Dorsal cnp sant'i'r-flai|K'd, wider than li'jl ; the vciilnil di, ■• ,iy- raniidal, hijflicr than the cnp. 'I'lii; disk has l,vo \\'iy larjfo oonspicnous plates (M" procossos disposed radially, wiiieh in the I'orMi of wings or Imrns j)a.ss ont from hetween the arms,

llastds two. liotli pentaj;onal ; the sntnre passing from (ho posterior to the anterior side of the ealys. Masai eiip shallow, and upon the posterior and anteriiir sides angnlarly eseavated for the U'Ception of the anal plate anil the anterior radial. Hadials wider than long, rapidly increasing in width npwards; snl)f|iiadrangular in onlline. except the anterior one, which is angular helow, while the others are tnnicate; the snjierior faces slightly nndnlated. Cosfals hiit one to the ray, which is often hidden from view, anil is always minnto and triangular. It snpports two distichnls, both axillary, which meet over the ape.x of tli? o'- d, their lateral faces renting npon the

702

TllK CIMXOIDKA CAMKUATA VV .NOUTII AMKHK'A.

i'

I. i

radials. tluii' slojiiiig u\t\wv faces ciippoi'ting from 1 (o 3 X 4 fixed palinars, of wliicli llie proximal oius toucli with tlieir outer faces the radi.ils. There arc no intorradials iior ititeraxillaries witliiii '.lie dorsal cup, aud, as a rule, there is hut one anal [dale,* whieh is elonyate-suhtriangular, aud always considernhly smaller than the radiais. The plate generally I'ises to the height of the railials and sometiuies beyond tlioni, but occasionally is shorter, and the two jiosterior radiais meet over its apex. Anns twenty', short, bise- rial, simple, arranged in groups of four, separated by the aiipendage.s, so as to divide the arms ot the same ray among two compartments. Pinnules short; in (do.'O contact. Tegnien highly elevated, p^'rainidal, pentagonal in outline; the sides of the pyramid interradially disposeil, and longitudinally depressed so as to form niches for the reception of the arms; the angles arc excavated or pierced, and support the large radial iirocesses, which do not necessarily pierce the test. Four of the interradiid spaces are of similar siz?, and composed of tiiree to six oblong plates; the posterior one is widest, and its plates are most numerous. The first interambulacral rests upon the ."iloping outer ends of two ailjoiuing palmars, and between two secondary I'adial dome plates ; it is Ibilowed by others, which are distributed around the bases of the wing-like appendages. The anus is almost central, and surrounded by a large numlier of minute pieces, which form a little cone, or. moie frei|uently. a sort of mammiform protuberance. Orals large, resting directly upon the intcrambulacr.tN ; the posterior one wedged in between the oilier four.

The wing-like append.iges, which probably represent the first radial dome plates, form tlie nio-^t cii:ua('teristie feature of this genus. Their form is very variable, being in some species spatulatc, in others daviform or cuneiform ; in somi! thin and knife-like, in others thick and rounded, while they bifurcate in still others. Tiie plates rise to the fidl height of the disk, and extend later- ally far beyond it and beyond the arms; they generally rest upon the surface iif tiie disk, within pits or grooves formed by the bevel'ed or inclined lateral edges of the intcrradial and oral plates. IJeneath them there arc over each ray two smaller radial dome plates of a second order, which rest against the plates of the dorsal cup. and enclose a large interanibulacnil jdatc. The upper edges of the latter plate arc excavated, an<l form the lower ends of the sockets tor the appendages. Ambulacra subtegminal. Colunni round ; axial canal small.

• 111 mil' -|«'ciiiii'ii \vc iiIkciviiI .1 siniill Iri.'iugiilir piece abiivr the rcu'nlar .iii.il jil^iti', wliich wc rog.inl as iiiciili'iital, auii imI uf .structural value.

f

V^:

IIKXAClUNID.i:.

703

Dklribution. — Restricted, so fur as known, to tlic Kiiskaskiii group of North America. Detiielied appeniliiycs are found in larj^e numbers in certiiiu localities of Alabama, Kentucky, Tennessee, anil Illinois, but perfect speci- mens arc extremely rare.

Type of the f^enus; I'tcrdlorriiii's rajiilalls (Lyon).

Remarks. — This genus was originally described b^' Lyon under vl.sVtvc- crinu.i, a name jirt'occupied l)y Miinr.ler. Meek and Worlhen, in ISCiCi. in revising the genus, stated that in some species the inlerradials rest upon the superior lateral laces of the ra<lials, wiiich is the case in the allied Talnvucriiiim, but not in I'liro/'irn'iiiin. Wetherby regarded the small trigonal costals, which Meek and Worthcn identilied as ''second radials," and which Lyon and Casseday had overlooked entirely, as accessory pieces. These plates, although present in every specimen, are in some cases completely covered by the distiehals.

Ci/a//iocriiiii!i protiificmiis Hall very probably belongs to this genus, but as only the basals and portions of radials arc known, wo are unable to descril)C it .satisfactorily.

It is very interesting that the anus in almost every .specimen of this gemis is covered with a Pluljccms, and in every case the anterior uuirgin of the shell is diretsted to the posterior side of the crinoid, contrary to the cases of 7V'(/'/o'/,'))/.s- /irmifji/urii'iiK and (lilhirls'irnimK /iifu roans, m wliicli the anterior margin of the shell lies to the anterior side of the crinoid.* That the Gastcropod invariably occupies the same position prove>, we think, that its presence then- is the result of h.abit and not of accid'.-nt. In PliroforriiiKS it could not have been washed in by the currents of the arms, as suggested by Meek and Worthen in the case of I'luli/criiitisi hrniis/i/icn'riis, for the arms in some species of I'/rrol(wriiiiis are so short that they do not reach the sum- mit of the calyx.

I't, roforriims is an aberrant and highly diffi'rentiated form. It approaches the typical form of the Camerat.i in the couiparatively large si/o of the fixed brachials, which to the third onler. contrary to what is the case in all tyjjical llexacrinida>. constitute a part of tin; calyx proper. The genus has its closest aiVmities with Tiilitrorr'nuis!, which precedes it in tiuu\ and is doubtless its ancestral tyi)(\ Their structural peculiarities tend in the siime direction; but while feebly indicated in the latter form, thoy attain in P/rrnlocrliii(s the climax of extravagant development. rur"l"rriiiiis, so far as wo know, is the

• To lliis fact ^^r. riiiiHcs it. Ki'vcs ilircclcil allonliim in liN iiilrrotiiiL.' |i.'i|u'r, On (lie Allacluiiuit of I'lat.vccnis In raliroci'iiiuuls (l'roci.'cil. .Vuur. riiil'>^ IS")-., Vul. X.W., p. i'i7)-

791

TIIK CRIXOIDKA CAMKRATA OK NORTH AMKHICA.

Inst surviving genus of the Ilex.icriiiitliV! ; and it is most interesting to find here again euipiiasi/.ed the truth which Palivontology teaelics us b\- so many examples, tiiut extravagance of' lorm and rank development in any group is the signal for its speedy extinction.

Fterotocrinus capitalis (Lrox). Phtto LXXIX. Figs. Ga, b.

l"!,??. Atterncriims cd/ii/iili' — Lvox ; (iicil. Krp. Kentucky, Vul. III., p. i'i, Phlc 3, Figs. 1, la-*. Isj'J. J'/iYutwri/n^f ni/ii/ii/is — Lviix iiiul CAs^^:DAT; .\iiicr. Juuni. Sci , Vi.l. XXIX., p. OS. 1891. Plerolucrliim ciij)i/ii/is — W. and Si'. ; Uevisiiiii I'alipncr., l*:irt II., p. UI.

Crown as viewed from above irregularly star-slmped, in profile resembling the form of a Corinthian capital. Dorsal cup about as wide as high, the plates heavy and without ornamentation.

Basals proportioi\alIy larger tiian in any other known species of the genus, forming a rather deep Ijasin, almost as large as the remaining portions of the dorsal cup together; the sides rounded, contracting at the upper end, and somewhat llattened at the bottom ; the median portions slightly concave, with a deep pit iu the centre, completely filled by the column. The upiier margin of tiie basal cup is indented for the reception of the radials, and deeply notched for the anal plate. The latter extends to the full height of the radials. but is considerably narrower ; it is trapezoidal, the upper angle being acute, the lower one obtuse. Radials ver}' short, their width almost four times their height ; the lower face convex, the upper excavated by the radial facets. Costals larger than usual in the genus, wider than long, trian- gular; the lateral faces a little concave. Disticlials twice the si/e of the costals, wider than long, the upper angles oijtuse. Fixed ]iMliiiars ] X 4, in contact laterally ; the two outer ones resting with one of their lower faces upon the radials, with the other against the disticlials; the two inner plates of the rays supported exclusively liy the disticlials; all succeeding brachials free. Arms four to the ray, short, rather strong, tapering to the tips, and incurving. They are biserial from the second plate, and tiie two series arc united by a zigzag suture. Structure of the greater jiart of the ventral disk not known. Tiie orals, of which portions are exposed, are elongate and almost — sonic of them completely — .separated by the wiug-likc ajipendages. The latter, as viewed from the side, are elongate subtrigonal, wilii rounded outer angles ; they are massive, deep, and llattened at the sides, thicker at

■<»

I

c-4

IIKXACRIXID.E.

795

the upper end tluiii at the lower, inul stouter in the niitlille than along tlie margins. Tlie sockets in wliicli they rest have not been observed, but must have been large, and probably extended to near the arm bases. Anus sub- central. Cohunn round and small.

Ilorkmi 'iiid fjicality. — Kaskaskia group; Crittenden Co., Ky.

l^ijpe in the Lyon collection.

Iiiiiitir/,'s. — Lvon described this species as having but one " primary radial," and two series of "secondaiy radials," oF wliieh the first series is said to consist of two, the other of .^ur plates. He overlooked the small costal, and regarded the two succeeding rows, which are partly distichals and partly pahnars, as " secondary radials." He further supposed (lie wing- like appendages to bo composed of three pieces ; but the fact is that the suture lines indicated in his B'iguro \h on Plate .3 are cracks in the specimen, and that plate evidently does not belong to this species.

t

Pterotocrinus coronarius Lvox. Flafc LXXIX. Fiijs. To, h.

1SJ7. Jsleroiriiiii) (?) i-oroiiariiis — Lvox ; Geol. Uip. Kentucky, Vol. III., p. 4"fi, Plate 1, Fips. 1, l<i. 1'5J9. l'/i'rii/i>i'fiiiii-i ci)miiii,'iii.t — Ij\us iuhI Cass., Svu. List I'ulii'oz. Kuliimid. (I'l-uuced. Ainer. Acad.

Arts ami t!i'i., VdI. IV., p. Wt-2). lS~il. Plci-ohn'i-iiiits f'lrniKdiis — W. mill Si'. J Revision Paia'ocr., Part II., p, 91 (I'rocceil. Acad. Nat. Sci.

Pliiia., p. iir>).

The structure of the dorsal cup is not known,* but the parts preserved are so characteristic of the genus, and again dilTer so essentially from the same parts of all other known species, that there can be no doubt that they belong to a distinct .species. The tegmen is remarkable for the extravagance of its wing(Ml processes, which project out almost horizontally from the calyx, an<l form with it, as seen from above, a five-rayed petaloid star. The petals, viewed from above, are broad, narrowest at the extremities and slightly bending downwiird ; the margin:' of the upper face curve upward and form a well defined riin around the median portions. The ai)pcndages are massive

• This sju'cirs was doscrilicd hy T.ynii from a single " unique criuoidal fragment," having, as lie said, "nrilluT l)a>al, radial, nor arm p.lales." This is tl:c type spoeimen wliieli we li.ave Hgiircd, and no other i^ known to have heen discovered. Yet il is a singular fact that tlicre is in ihe Museum of (.'omparative Zooloiry at Candu'idge a learl east of what seems to have heen the same specimen, lint having the nussing dorsal portion of :lu' ealy\ intact and showin? all the eliaraelers of the genus. This east is supposed to have liecn given to Professor L. Ag.assiz ahout ISJO; but whether il was un\de from a partial n'sloration of the specimen which afterwards became I.yon's type, or from another almost duplicate spcciuien, or vvhelher the lypo was couipleic as originally fouiul, and the dorsal cup broken off and lost before Lyon's description was made, can only be conjcclnrej.

720

THE CRINOIDEA CA5IERATA OE NORTH A3IERICA.

and form irregular triliedron.s with uiululating faces and rounded angles, the side by which tiicy are nttacheil to the calyx touching with one end the orals, and with the other the plates of the dorsal cup. Tiie median part of the tegmen (the nucleus of the star) is concave, except its posterior side, which is slightly raised by the anal structures, which occupy fully one third of the central space. Anal opening subcentral ; surrounded by numerous small plates, wliieli are cnclo.-icd by larger ones of irregular arrangement. The orals vary in size as well as in form; the posterior one, which is wedged in between the others, is pushed over to the anterior side ; it is rather snnill, slightly convex, and subtrigonal in outline, though actually pentagonal ; the two anterior orals are larger than the lateral ones. The extreme outer cnd.s of the orals are bent abruptly downward so as to produce, together with the depressed inner ends, sharp edges, which connect with the projecting mar- gins following the appendages, forming with them n well defined rim around the whole upper surface of the calyx. The .spaces between the appendages are placed at right angles to the ujiper face ; they are snbtriangular in out- line, and distinctly grooved for the reception of each separate arm. At the four regular sides there are apparently six interambulacral pieces, and prob- ably eight at the anal side.

II<in~.on and L"calitij. — Kaskaskia group ; Crittenden Co., Ky,

I'Ujic in the Lyon collection, Jeflfersonville, Ind.

Pterotocrinus depressus Lyon and Cass. Phde LXXIX. Figs. 2a, h, c, d, e.

1559. LvoN mill Casskoav; A)iicr .Inurn. Sci., Vol. XXIX., p. fiS.

ISdO. SiHMAKD-, Trans. C't. I.ouis Ara<l. of Sci,, Vi.l. II., p. MI.

ISi.l. MekK illlil WoUTllKN; Orol. Hep. mill. .is, V.,1. v., p. 55U, V\:\W 21, Figs. 1,1, 13,7-C.

ISsl. AV. mill Si'. ; H.'visi.iii ralicuci-. Tart II., p. 91.

This .species is distinguished from all otliers by its enormous, flat, knife- like appendages, and by the po-^ition of the anns, which occupies the top of a central slender cone. C.ilyx a little higher than wide; the dorsal cup shorter than the ventral disk, doprt'ssed howl-shaped ; the sides straight or slightly convex; the lower portions rounded. Plates smooth and the suture lines rather indistinct.

Basals of moderate size, but very .slightly projecting, with a shallow con- cavity at the bottom, which is completely filled by the column. Radials irregularly pentagonal, the sides rapidly .spreading, especially tlio.se facing

A

niCXACRINID.E.

(97

the nnul pinto; the uiipor faces at both onds nro sliglitly oxo.avntod for tlio reception of the two oiUor pnliimrs of the proximal row, and tliL're are similar excavations at the middle portions for the costals and distichal.s. The anal plate, whiidi is placed within a notch formed by the basals, is either pentan- gular or triangular; when pentangular, its lower part rests between the rndials, the upper between two of the palnmrs; when triangular, the two posterior radials meet over its apex. Costals small, trigonal. Distichals as largo as the fixed pnlinars. The latter, of which there are throe plates to each series, are wider than high, and quadrangular, except the outer ones of the first row, which arc cither pentagonal or hexagonal. Anns short, slightly tapering, flattened on the back, and bi.xerial from the fourth or fifth plate. They are composed of very short transverse pieces, which are united laterally by a .sharply zigzag suture. Pinnules strong and closely packed. Ventral disk conical, once and a half as high as the dorsal cup ; the plates arranged similarly to those of P. pijrutuHliili'i ; but the posterior oral, instead of being central, is pushed completely to the anterior side by tho anus. The anal opening is located at tho top of a small elongate cone or short tube, which occupies almost tho centre of tho disk. Tho interradial spaces are lon- gitudinally grooved to their full length. Those of tho four regular sides are constructed of three good-sized interambulacral pieces, succeeded by the oral plates. The posterior side has 2, 3, and 4 pieces, followed by numerous smaller ones, which sui)port the anal tube. The sockets for tho reception of tho winged appendages are narrow, the appendages leaf-like, perfectly fiat on their lateral faces, and thickest at the place of attachment, whence they thin out gradually into a sharp, knifo-liko edge. As seen in tho specimen, they look like fivo innnenso blades, which project out in all directions far beyond the limits of the arm.s. The interdistichals and seconchny radial dome plates are comparatively small, the former le.ss protuberant than in the preceding spi ios.

Ilorizmi and LocnJihj. — Kaskaskia group ; Gray.-^on, Edmonson and Pu- laski Cos., Ky.

T'ljpes in the Lyon collection.

VJS

XUK I inXOIDKA CAMKHATA Ul' NUIMII AMEUICA.

Pterotocrinus pyrimidalis Taon ami Cass. riute LXXIX. Fhjs. 4,1, b.

1859. I.voN niul Cassbp.w ; Ampr. Journ. Sci., Vol. XXIX., p. CO. ISOfl. SlUM.lUD; Trans. SI. l,i)uis Aciid. Sci., Vol II., p. 3Ui. ISSl. \V. iiiul Si'.; Hivi.Mim I'aln'ocr., Tart 11., p. Ul.

A litl.' liirj^er tlinu tlio preceding .<<|iccios. I)or,«iil cup fiiiicor-«liapetl, broadly truncttte at tlie lower end ; llie sides rapidly 8prea<lini;, especially from tlio top of the rudials upward, liringing the upper portions into a nearly liorizontal po.sitioii. riates tiiick and without ornamentation.

Basal cup very short, a little projecting laterally ; ohlong, the longer diameter transver.«o to the suture ; the (H)[)er margin distinctly notched for the reception of the aual plate, and somewhat less toward the anterior radial. Radials subfiuadrangular, rai)idly spreading, fully one third wider at the upper end than at the lower ; the median portion.^ of the upper faces slightly excavated for the reception of the distichids and the middle part for the costals. Costals very small, trigonal. Distichals snuiUer than the palinars. The Hrst and second palmars lai'ger than the third, and forming part of the calyx ; the third partly free. The lirst palmars of the two outer divisions of tlie ray are pentangular, and rest with their lower faces against the sIoi)iug upper faces of the disticlials, with one of their lateral faces upon the radials, and the other against the (hst palmar of the inner division. The second palmars are sujiported by the llrst. and rest at one side against the second and third of the two inner divisions, and at the op[iosite side against the })almars of adjacent rays. The three palmars of the two inner divisions thus meet laterally, and interlock with those of the outer divisions. Arms four to the ray, short, biserial above the third palmar. Anal plate lo/enge-shaped, largo, its upper cud inllectiil and not seen in a side view. Ventral disk, the appendages removed, pyramidal, the sides llattened or slightly concave, cov- ered with longitudinal grooves for the reception of the arms. The iuteram- bidacrais at the four regular siiles consist of three plates in two rows ; they are of (djout equal .size, and all longer than wide; the first, which is Hanked by two st'condary radial dome plates, is hexagonal, the two succeeding ours j)entagonal and in contact laterally with those of adjacent sides. The latter plates, as also the orals, are bevelled olT at one side to a third of their width, and the depressions thereby produced form the sockets for the ujipeudages,

1

11

IIKXACIUXID.K.

709

wliich in tliis spwiiw do not iH'netriitc the test, but rost cxclusivi'ly iigninst the sloping faces of iidjoining plates. The nnal xhh lins two intorninbulacial pieces in the firsft row, and three in tho second, wliiuh latter arc followed hy ninncrouM siiialler plates. Anal openini,' Hulicontral. directed obliciuely up- ward.x. The posterior ornl Ofcupies a central position, being pushed in between the other lour; tlie latter rest against the interanibuliieral plates. Tiie form of tiio appendages is not dednitely known, but we judge from the form of the sockets, which are narrow and elongate, and from fragments in contact with tho specimen, fiiat they were probably similar in form to tho.se figured by Lyon (Geol. l{ep. Kentucky, Vol. III., Plato 111., Figs. 1,^, /;), which he mistook for tho appendages of P. cajjitalis. The interdistichal plates are large, greatly projecting and angular in the lower portions, while tlioy form deep grooves in tho upper. Arms unknown, t'ohnnn round, narrower than the concavity which it occupies.

lI'iiT.mi (iitd T.iH'dlltji. — Kaskaskia group; Edmon.son, Grayson, ami Brockenridge Cos., Ky., and Morton Co., ind.

Type in the Lyon collection.

Pterotocrinus acutus WEniKunv. rinte LXXIX. Fhjs. 3rt, h, c, <1, c,f, g.

X'-l'i. Wktiieiuiv ; .Imini. rincin. S,.r. N;it. Hist., Vul. II. (Ooli.lifr \t),), riiilo 11, Fijrs. 'ia-e. IS^l. \V. iimlSp. i li(vi>inu I'iilii'ncr., I'art II., |i. 91.

Sui. Vli',-ni,„Tii)m xjin/iit.i/iin— \\"i;riiKiiiiv ; Joiirii. C'iiichi. Scic. Xal. Hist , Vul. 11. (October \o.), n.il.- 11, Fiijs. .•!,/-<•.

Svii. (-) l't'-rolocriiiu.i ni^otiis — I, vox mid Cass., ISj'J; AiiiiT. Jouni. Sci., Vol. XXIX., |i. 71.

Of tho typo ol' P. p//r<im!ih(/iK Lyon and Cass.; but the basal cup much smaller and the bottom less deeply excavated than in that species, the radials proportionally longer, tho anal plate smaller, and tho sockets for the recep- tion of the radial appendages wiiler. Tlio appendages have the .shape of a horn terminating in n point instead of an edge. Dors.il cup low basin-shaped, the upper portions flanging outward ; pentangular .across the arm bases.

IJasal disk very shallow, rounded at the outer face, not truncate at the bottom, and but slightly excavated. Neither the interba.sal nor basi-radial sutures are grooved. IJadials .short, somewhat irregidnr in form : their upper faces moderately concave ; once and a half as wide at tho top as at tho bot- tom, and twice ,as wide as long. Anal plate lozengo-shapod, the acute upper angle wedged in between the radials, the obtuse lower angle resting upon the

bUU

llli: ( Ul.NOIDKA C'AMKliATA OK XOIMII A.MKlilCA.

?:,»

L.'iMiils, Tlic co-tii!s vt'i'v iiiiiuilo, suiiu'liiiios coiiiiili.'li'ly cowivd hy tlie dis- ticliiils, wliicli are a littlu laigci' tliiui llio paliiiars. 'I'lie latter, to the liuight of tlio third plato, I'onsist of sliyit, traiisvoisi', siiij^lc pioct's, tlic [dates of tin.- two lowor rows beiiiy iuLdiidud in tiie calyx ; wliilo those of the third row, which are siinnouiitcd oii the hack hy a small sjiiiie or eloiigiite node, are free. i\nns hiserial ['nmi the iburth plate, and coniiiosed of two rows of veiy short pieces, which aw uniti'd laterally hy a zijf/.aj,' snture. The arms are Hat, tiiperinij. and so short that their ends do not meet npon the siunniit. \'en- tral disk pyramidal, a little shorter than wide. Interamhulacral spaces trian- gular, and to their full height covered with small longitudinal grooves in which the arms rest. At the fom' regular sides theie are four jilates, three of them intera;nl)ulacral. arrangt'd : 1 and '2, followed by an oral plate. The two upper interaml)ulacral pieces and tlie orals are strongly hevelieil at one side to form the sockets for the appendages. The upper i>arts of the four smaller orals hend abruptly inward, and form a sort of platform, which is almo-^t inviirial)ly occnjjied by a sjucimen of I'iitli/i'inis rluslimixi , ><o as to ciiver the anal oiiening and the posterior oral. Anal interradius a little the widest, and e()m[iost'il of a much larger nnnd)er of plates. It has also only one plate between the arm bases, but this is followed by three or four pieces, and numerous others wliicii gradually decrease in size upwards. 'J'he pos- t.rior oral is conve.K and semiliniate. one of its sides being excavated by the anal opening, which is almost central. The sockets for the appendages are widest at the top. whence they tap ;r gradually downward, and form a sharp angle which enter- the upper end of the interdistichal I)elow. 'i'hc appen- dages are long and somewhat variidde in form ; as a rule, they are wider on top than at the bottom, a little deener than wide, deepest at the jiroximal ends, and they terminate either in a sharp point or a transverse edge. Column small and round.

Iluri.von aiitl Loi-aJil;/. — K.'isknskia gronji ; Sloans A'alley, Pulaski Co., K v.

T'/pcn in the collection of Professor Wctherby.

Rihvtrhs. — We regard Ptcnitiifn'mts Kjiatiil'dus AVetherby as identical with the above species. The two were said to dilTer in the form of their ajipenilagcs, the one being awl-shaped at the distal end, the oilier more spatulate. Comi)aring the figures of the type siu'cimens. the iliHen'Uce is very slight, and a comparison of a large uninber of spines collected from the (linnps of the Sloans Valley tunnel shows condusivt ly that there are within the limits of this sjiccies even greater vaiiations than those referred to.

-f

,. «

lIKXAC'UIMD.i:

801

Lyon's Ptcrotocriniis rKi/Dniin is prolmlily also iiUMitical with this sju'cii's, but as tiic type siiocimcii is frngineiitarv iiinl hadly I'l'iishuil, no trilicMl coiii- parisoii is pussiijiu, ami \vu think it advisaMo tu accept Wclhurby's naniu.

Pterotoorinus acutus, vai. biftircatus (Wethkuiiy). rinte LXXJX. Fhjs. Ua, b.

ITO. 'Wktiieiuiv ; Jcmrn. riiioin. Sue Nui. lli»t. ((liMnliir Nn). I'liilc 11, Fiu". 1.', *, r. 1>>S1. W. iiiul Si' J Ucviji.m I'ah.dor., I'lirt II , p, ',11 (I'niciid. .\fiul Nal, Sci I'liilii., y. il):i).

Tlii.s vaiiuty ni^rei's in the genL'nil unanjienicnt of its i)lali's witii /'. (irit- tus, but differs from it in the form of tiie dorsal cup and tiie form of the appcmhigcs. The cup is higher and more conical ; tiie liasals proportion- ally deeper, their lower faces distinctly excavatt'd, and sharply eilged around the margin. The appendages are long anrl extremely heavy thronghont ; they bifurcate widely, in such a way that the divisions fiom adjoining rays meet at their ends and .sometimes overlap each other. Column small, fdling Bcnrcely one half of the basal cavity.

Iloiuon and L(irn!il;/. — Ka.skaskia group; Sloans Valley, Pulaski Co., Ky,

Ti/pe in the collection of Prof. A. G. Wetlieiby.

Fterotocrinus crassus .Mi:i:k and Wfiuxnicx. r/atc LXXIX. Fiij. S.

ISfiO. niciocrinus ( Pl''ro/orrinnt) rrantiit — Mki;k iinil \Vii|itiii:n ; rrnoccd. Acad. Nut. Sri. riiiln., p. ,'(92. ISiiO. I'h-i-otoriiiiiii rr«<«M— .\1kkk niiil WuiiTilKN ; (icul. I(c|i. llliiKiis, Vol. II., j). 2'JU, l'l;ite 2;i,

Fi«i 2./, 4. 18S1. rtenli>criiiii.i criistHS — \\. niiil 8p. ; Ui'visiim I'liln'dor., I'liil II., ji. 91.

This species has its clo.sest alTmities with P. jii/nniiiihi/is Lyon and Cass., but is .somewhat larger, the basal cup deeper, the arms longer and heavier. Dorsal cup basiu-slmped, more than twice as wide as high, very broad at the base, the sides less spreading than in any of the preceding species, and some- what constricted at the basi-radial suture.

IJa.sals very large, forming a rounded shallow cup. distinctly concave below, and widening gradually from the rounded lower margin to the con- stricted upper face. Radials a little convex, broader than long, considerably wider above than below ; their njipcr faces slightly concave, supporting the costals, distichals, and the outer palmars of the (irst row. Anal plate snb- quadrnngular, contracted above, the upper cid inflected. Costals very small,

101

802

IIIK CUIXOIDKA CA.MKUATA Ol" NolMIl A.MKIMCA.

oflon iiltogetliur hidden from viow. Distieliiil.-t and lower iinii plates nearly of eiiiial size. The arm.s tree IVoin tlio Hocuiid jdate, and biseri(d from tlio fourth ; they nrc umiMiially xtroiig, rounded nt the haek, and eoniiiorted u{ two roWH of short, transverse pieees. I'innule.s slender and elosely arran;,'ed. '{"lie appendages are thin and knii'e-liko at their upper edges, nuieh thicker below (J[eek and Worthen) tiian above. Constrnetion of the ventral disk nnknown. Coliiinii round, occupying about one fourth of the basal concavity.

IL'r'coii iiiid Ldciilitij. — Kaskaskia group; Ilardin Co., Ills.

Tijitc in the Illinois State collection, Springfield.

J

Pterotoorinus ohesterensis Mi^k ami Wurtmek. riate LXXIX Flifs. Sii, b.

l^fiO. Diiiocriiiuf (Plfi'oloeriim)) eiffleremh — Mt.f.f. iiiiil Woutuin; I'lnccnl. Aonil. Nnt. 8ci. riiila.

p. ;)MI. I'^ijfl. Pli niturriiins ci,tlmn.<it ~ Mr.r.ti mid Wuiitiiks; Gi'ul. Ucp. Illinois, Vul. II., p. 2'J2, Pliiti; 23,

Fig». !<•, t, c. ISS], PlirotofriiiHa cieileri'mh — W. iiiul Si'.; Ilt'visicm Piilivocr., I'lirl II., p. 'Jl.

Tlio smallest known species of tho genus. Sides of the dorsal cup dis- tinctly concave, rapidly sjireading upwards; the base truncated, and its lower margin projecliiig ; the plates without ornamentation, and the suture lines not grooved.

Basal cup aliout one thinl the width of tho calyx nt tho arm buses, nnd about three times as wide as high, truncated and concave below, the concav- ity surrounded liy an angular rim. Kadials not quite twice as wide as long, wiilcuiug rather rapidly from below, tho superior faces a little excavated ex<i']it 'lie outer ends, which are .slightly triuicated. Cosfnls small, trian- gular. Distichals irregularly pentagonal. Fixed palmars four; the two outer ones in tho same line .villi the distichals, an<l like them reposing upon the nidials. Anal piece subovoid, its broadest end about as wide as tho radials nt their lower faces, tho upper end angular. Arms biserial from the third pinto up, small, .ind rounded on tho back. Structure of ventral disk anil form of the appendages unknown.

Ifiiri.iiH mill LiiriiUhi. — Kaskaskia group; Hardin Co.. Ills.

TtjiK in tho (Worthen) Illinois State collection, Springfield.

1

4

ACROCIUNID.K W. nml Sp. (\m^).

MOXOCVCLIC. FJaSALS HEPAHATFI) KIIOM TIIK IlADtALS IIY A LAIKIK I1KI.T OK ACf KSSOIIY l'IK(E8. HvMIAI.S IN CONTACT KXCHI'T AT TIIK I'OSTKIIIOU SIDK, WJII.IIK TIIKY AIIK BKrABATKD UV AN ASAL I'LATK. KTIiUCTUUK OTMKIIVISI.; AH IN TIIK IIkXACIIIMD.E.

O'l 'i/ii'jicdl mill (lii:iji'(ij,lili't(l JJiilriliiitioii. Number of known speclei.

FollMATIoX.

Ai iiiHiirMH.

Carboiiifciroua.

Coal Measures.

1

Subcarboniferous,

Kaskaskia group.

1

St. Louis group.

1

Total spccii's

.1

luinarl-.t. — This family consi.sts of tlio single gemis AcrdrriiiKu, which i.s only known from Ainorlcn, where throe species have heen foiinil : one in eacii of the upper memhers of the Snlicnrboniferous, and one in Die Conl Measures. It represents, therefore, tlio end of the Camerata, so far n.s our invstnt knowlegc goes. It appeared after all the other families wore extinct, except a small remnant of the Platycrinid!i> represented I;y a small but very prevalent species, and the IlexacrinidiB. from which its derivation is very apparent. It survived in the Carboniferous, from which ii single very .small ^pccimen is known.

In the interposition of accessory pieces between the primary plates of the calyx, the AcrocrinidiV) approach the IJeteocrinlda) ; but the two families

i

801

Till", ( IIINOIDIA fAMKIJATA OI' XOHTI! AMKIMCA.

ililTor OHHontiiilly in diIht ro»iioctH. In the I{i'teoi'riiiiiIii> tlii'ito piori'N mo inti'odiiceil iiloiig (li(> nidcM ol' llic i'ii<liiil.H ntnl llii' lower lii'iicliiiil-<, iiinl ticlwccii tlu' iiriiiiMiy iiitc'rliiai'liialri, Imi in tlii> Arrociiiiida' hohiw tlio railials iiiiil lii'twueii tlu'in mill tliu bnwils. In the one ^'lonp the haMiilii me in contnct witli the i-niliiil.", ami the radial^ are xopaiiiti'il all nioniul, while in the other the radial-t are in eonliict eNce|it at tln' anal hide. l)iit are widely >'ei)aiate(l tVoiM the liasaN liy a new net ol'|ilate.i, for which ihi' term " MiibradialM," if it iiad nut been utherwi.ie umciI, wuiild be Mpprupiiute.

to

i 6.

i5H>

ai

f^

Fiu'. '21. Jcrnrri/iH-t. i = lms;ili; If = milinl8i /=costiil»; r- «|«'ci:il iiii.'il |iliili'. All llic ullnr pl^trs nrc Kiipiili'innilnry piici*.

Tlie Aci'oorinida' arc niidoiibtedly closely related to the Ilexacriniiliv ; in fact the introduction of a narrow belt of supplementary pieces between the l)asals and ra<lials would be sullieient to transform any /)ii/i'>i;-iiiiis into an ^iif'iilnns. In both genera there are two e(|ual basals, the radials of both enclose an aual plate, in iiotli of them the arms are souietimcs pendent, and neither one has iiiterbrachials entirely within the dorsal cup. Considerinj^ that the number of these supplementary pieces increases with the j^rowth of the orinoi<l. as is shown conclusively from the specimens, it .seems to u.s more

I

$<

A( l«i( ItlMD.i:.

Mo

lliiiti iinilnil)Ii' flmt Arrorriniix rcpri-r*!-!!!'* |)livIi>K('in>lii"ulIy ii lii^'lily ilifToron-

lialfd fiHlll of Jiirlmrilllili. TIlis i.t I'lll'tllOl' Cliiilii lliril liv tliu I'lK'l lllllt

Arrorrliiii^, wliilo in imrt ci)iitt'iii[iiiiuiit'ou.s uitli /tii ho, linns, u, to fur a* kimwii, tliu la.it Niuviviiiij gciiiH ul' tliu Ciuiiuruta.

ACROCRINUS V.vM.eiL.

l^'ij, Y\Nnt:ii.; Ani.r. .Iniirii, Sii. uihl Ail<, Vul, \X.(iii'W •cr.), |i. 1115.

IViS ||»|,,.; (i,.,,l. |(,.|.. I.,«„, V,,l, I,, I'lilt II., |). 'IVJ.

I'".', »'i(i|..Mi til; llill. I. IIImiuii SlHlii .Mm-cmiii, |i H; nnil (iiul. II, p. IIII11..1., V..1. VII , |i ;li:l, hW W. iiii.l Nr ■, |(rti,|„ii I'lilii'iicr , Vnrl III , p l.'l (IV nl. Atvul. X,,t. S, 1. I'lnla , y. ;!l'i)

Calyx iiiiiiiliom- or uni-sli; |ic(l, loiij^ei' tliaii wiili'. JJa.xals two, ccnial. roi'iiiiii^ a low liuMin or (lat (li.«U ; tlio Miitiiru linu pa.xsiii)^ IVoiii tliu anterior to ilic |iii-ii'rior Miilu ; tin' iiinicr j'ai'o straijflit. lia<)iaN xoparatod fimn liic lia^ialM liy an inildiniti' niiinlicr of .Miipiilcnu'ntary pieces placi'il in row.x, alter- iiatuly arrangt'il, o.\e<'|il ili(>.i(' su|>|i()rliii^ tlio anal |'lale ami anterior radial; those of every sneeecdinj^ low are .soniewliat larjrer. The plates are in part radial and in part inl('rr:idial. llie latter consiilerahly the most nnineroiis at tile [losterior .side; the n|ipernio-t row .supports the radials, which are moder- ately huj,'e and enclose an anal plate. Hadials at their n|)per faces hroadly aiiil deeply excaval<Ml for the reception of the costals and di.stichals. L'o.-tnis very small, snlitrij^onal. Dislichals two, the lower one placed against the -loiiinj; faces of the costals anil npon the radials. Palmars two if there is another hilurcalion. Arms hiserial, either erect or pendent; in the latter case the aiuliidacra esposeil. I'innides long and clo.sely packed. \'entral disk Hat, coini)o.scil of sm ill plates. Anal opening eccentric, near the margin of the disk.

I)islrili'i/i',ii. — Arrnrriiiiis, tho only gonns of the Acrocrinidir, is ropro- senled, so far as known, only in America, and there only hy three .-pecic.s, which lange from the St. Louis gronp to the Coal Measnre.s.

7///"' of the genus: Air'<rr!iiiis Sliiiiiinnli.

/i'- /////•/■<. — In the Hevi-ion, Part 111., we descrilicd this gpnno as having •'three radiids," or, as we would s,ay now, a radial and two costals. Since then we hav(! olitinneil v(mt much better .xix'cimens than were ever known before, and these prove conclusively that the so-called first radial is merely nn .accessor}' piece, and tliat the plate above it is the true radial. Our interpretation seemed to be rpdte reasonable in the case of A. Wnriln ni, in which the lower face of the radials rests upon a single plate, which natu-

806

Tin; ( lilNOlDK.V CAMK.UaTA ok Nolilll AMKKK A.

rally occtijiii's a riidial iiosilioii ; l)iit it doi-.s not agri'o witli A. SliiniKinH. In tliis .spoc'ius tluTo arc oiilv two plates in radial .snt'co.-sion ; lliu jilatc wliirli wu (it'.-<cril)od as the " second " radial rests upon two contiguous plait's, whifli luc both iiiti'irndial.

Tilt' ai'co-sory pieces wore multiplied by the addition of new rings above the basals. This is well shown by the snuill speeiini'U of ,1. Wurlhaii, and liy some of the smaller si)eciinens of ^1. (itiijiharu, in whieh the plates of the last ring are yet trigonal, while in the la.ger spoeiuiens, with additional rings, they are heptagonal.

Acrocriniis Shiimardi v.\MM:r.i..

riiii Lxxx. r!<,s. J >, J.

1" 17. YAViin.i. .■mil Si'i m mih; ConlriliiUinii'i (leiln^n Ki iiliickv. I'l.ili' 1. ,.;,■. ^ (iK'iiri'il wilhoul ili'scri|i-

tiuli ni- liaiiu). 1^.").'), YiMH I.I.; ,\iurr .limni. Sr'i mid .\rl.s, Vi'l. X\. (mw sit.), p. \'^'> («illi liciirr). Isja. W. »m\ Si'. ; Hr\ir>iciii I'alinicr, l';irl 111 . p. IJJ.

Svii. ./.■.■".•/■///«.< «rtwyu/-/«iji — ll.\ 1.1. J l!?."'^, (iiul. Kij'. !ii«:i, V»l. I., riut U., p. O'.IO, I'liitc !!.'>, Fii,'s, \)fi, //.

A large speeies. Calyx nrn-shaped. a|)parontly more limn twice as long ns wide ; tlu' plates thin, almost Hat. and williout ornamentation.

n.isals lonuing a large i)asin ; the lower face rather broadly truncated, and extended oulw.ir.l into a siuidl rim ; the interbasal suture slightly grooved. The [jlates separating the basals from the I'adials arranged in fourteen to twenty rings, more or less, each ring containing from twenty-live to lhirt\' plates, except the np|)er on, whieh has but eighteen. They are arranged in a similar manner as in .1. U'-y/Z/i/'/. gradually increasing in size upward, ami the lower ones longer than wide, the up|ier as wide as louii. IJadials irregularly heiitagonal. larger than any of the pii'ceding plates, slm! t but extreuu'ly wide, llirir width being tiu'ee to lour times their height ; the up|ier l'a<'e of the railials is exca\atecl to fully three fourths its width, form- ing a deep. r(juu.Ieil facet, which enclosi's the eo-tals and both distichals. Anal plate a little longer than the radials, and like these suppcaled by foiu' jilati's. Costals one. minute, trigonal, occupying about one tenth the widili of the face;. Oistichals and palmars two, transversely linear; the latter but half the width of the distichals. Arms apparently eight to the ray. erect and biserial. The structure of the disk has not been observed, but it was doubt- less llat. and the anal opening, as shown by the Hpecinuns. IVei|uenlly was covered by a (iasieropud. ('ohunu of nitnl'M'ate size, comjjoscd of rather

A( UOC'UINID.K.

8U7

short joints, wliieli nonr tlio oiily\, iit intervals of five to six, iiro intcrniiUeil iiy Ionj;oi- aiul soinuwiiat witliT iilates.

JIi>n'.viiii (did Loatlifi/. — Kaskaskia group; Grayson and Pulaski Cos., Ky.

7}/jie in tlio Yau'lcl! collection at I,ouisville.

/u'liiarliS. — The fragmentary specimen from the same horizon of Popo Co.. ills., for which Hall proposed the name Acrocflni'K iirmi/nniiis, is in all prohahility identical with this species. It has preserved only tin- hasals and a lew liiij^s of the intercalated plates, which arc not siilllcient for acciu'ato comparison.

Acrocrinus Worthoni Wm ir.sMCTn.

r/(itc LXXX. Fh/x. Mi, b.

1S^2. W«iisMrTii; Hull. I. Illiuui-i Stiilc Miisfuiii Niil. Ilisl., p. U; iiml (lc(il. l!i-|i. jlliiini'i, Vul. VII.,

p. .'ilH (willi ili;ii,'niiii). ISSJ. \V. lllhl Si'.; ItivUiMii |':,I.'. r, I'.'ul III., p. 12J.

This species was dexM-ihed from a sini,de specimen, of which onl3' the dorsal cup is preserved. This, however, is in excellent preservation, ami, notwilhstandinj^ its smidl size, every plate can he readily traced, 'i'he cup is cal^'culate, hroadly truncate at the liottom, whence it curves rather abruptly npward, its width slij.ditly decreasinj^ to the upiier end. The entire lenjjth of the specimen is hut o mm. hy 1,^ mm., its {iroatcst width, and I mm. across Hie top of the radials. The surl'ace of the plates is without ornamentation, but sulliciently convex lo lirinj^ out the suture lines.

Basals eomparativel) larj^e, restricted to (ho truncated lower face of the calyx, and not visiliie f on a side view ; they are si'i arali'(l iVom the radials hy si.\ rin;j;s of plates, which increase in size uinvard. 'lliere are twelvi- plates in the first riii>r, trian}i;ular in outline, whiidi are so niiuute that it retiuires a i^ood inaynirur to discover them. Aiiollier row of twelve some- wiuit larger plates constitutes tlu; second riiii;. The latter are jdiiied hy their lateral faces, the lower nnirjes resiiiif^ hetwoen the sides of the preced- ing; plates. Five of them arc place<l rai'ially, seven interradially. one at each leifidar iiiti>rradial side, and three at the anal side. Ten of the plates are hexagonal, the middle one of the anal side and the anterior radial one heji- tagonal and truncated above, 'i'he third ring consists ol fourteen jiieces, larger than the preceding ones, hut less regular in their arrangement ; twelve of them alternate with the plates of tin- second ring, and the two others re.-t ii[)on the truncated upper faces of the two larger heptagonal

808

TllK CKINOIDKA C'AMKHATA OK NOIilll AMKHICA.

pieces of tlie aiiU'iiur and jjcisterioi' si les ; liv this iiirangeineiit tlie jiiece

ilirecteil uiiterioilv is the only radial plate of this ring; live plates oeciijjy

the anal interradius, and the limr oilier sides laeli have two. The I'ourlii

ring has sixteen plates; some hexangiilar, others peiitnngnlar, five of them

radial, the others interradial; of the latter, live oeenpy the posterior side,

one the postero-lateral sides, and two the anicro-lateral ones. The fifth

ring contains twelve plates, all of which are interradial and arranged in

groups of 4, L*. '2. '2. 2. At fom- sides, the two adjoining ]ilates of dilVerent

interradii meet radially liy their lateral angles; but at the posterior side.

which has four plates, the two middle ones are separated hy plates from the

fourth and si.\tli ruigs, which meet between them. Of the sixth ring, which

is followed by the radials, five of the jjlates are radial, seven interradial ;

three of the latter occupy the anal side, two the regular sides, 'i'liere are in

all seventy-eight accessory pieces, of which sixteen are radially disposed, the

others interradially. Tiie radial jdatcs of the anterior side, and the plates ol

iiiljoining interradii together, are arranged exactly like the plates of the

posterior side, there being :n eitiier case an iniintorruptud series of four

plates arranged longitudinally, and ten plates to each side; but, while the

one row supports a radial, tlie other bt'ars an anal plate. The true railials of

the spi'cies are larger than the plates whicdi support them, wider than high,

and iiexaiigular ; their truncated lower faces rest upon the radial plates of

tlie preceding ring, the lower sloping faces upon the adjoining interradial

pieces. The upper faces of the radiids are excavated to three fourths their

width into a rounded facet similar to that of I'/uh/iriiuts. The anal plate

is somewhat longer than tlu' radials. but unrrower.

I/iirliiiii mill L"rii/it//. — L'oal AFeasurcs; I'eoria Co., Ills.

2'i//i<i in the Illinois Slate coUection at Springlield.

Acrocrinus amphora w. .'nil sr. (mov. ppec).

j'/,iir rxxx. ri>,s. .; ^- n.

Smaller than .1. Sluiiininli. Calyx urn sliM|ied. more tlinii twice as high as wide, gradually widening IVom tiie lower I'lid to the middle, then contracting a little to the top of the radials. The plates thin, very .>-lightly convex, and wiilniut ornamentation.

IJasals small for the genus, (orming a rapidly spreading l)p«in with a slight truncation at the lower cud, corresponding to ihi' width of the cdliiinii.

1

4

ACROCRIXID.K.

809

-•Ir

r

;■■;

^

1

^;-

The bnsnls nro followed hy from fifteen to twenty rings of ncco.isory pieces — the number viiryinj^ nniong the specimens — and eiicli ring consists of twenty to twenty-four piiites, except the two upper rings, wiiich contain ijut twelve. Of tiie upper ring, seven plates nre nrranged inlerriidially — three occupy the anal side and one the regular sides — which alternate with the radial pieces. Most of the accessory pieces are hexagonal, and angular at top and bottom : but at the anterior and posterior sides those constituting the middle series are truncated at both ends. Hadials large, one third wider than long, deeply excavated at the upptr face into a facet which contains the costal and both distichals. Anal plate of the s;une width as the radials but considerably longer. It supports several snudl plates, which projcf't outward, and may bo readily taken for the base of an arm. Costals wiiler tiian in the two preceding species, jjut e(piaily short ; the ilistichals propor- tionally longer and narrower, rounded on tlio back, and distinctly curving outward. Paliuars free from the second or third jjlato, ciuving outward and downward, bringing the arms into a pendent position, their backs next to the eal3'x. and the ambulacra and pinnules on the outside. Arms twenty, moder- ately long, descending far beyond the basals; they are composed from the fourth or (ifili plale of two scries of rather short joints, and rest, apparently iiumovably, with tlicir backs within deep longitudinal grooves or impressions on tiie s\u'fac(? of th(> ilorsal cup. Pinuulcs long, closely packed ; composed of long joints tlu'cc times as long as wide, their ventral furrows, like those of the arms, lined by two rows of covering pieces. A'entral disk Hat, the midillc portions comjiosed of numerous small perisomic plates, from wliicb well dilinrd auibula Mid pieces, alternately arranged and suturally united, cuive downwan!, and pa.>.s out into the iM'ms, Anus eccentric, on a li'V(d with till' upiicr surfacr. placed about half way between the centre of the disk aiul its outer margin. Column round, the joints nearly of equal mo.

Iloi-'iy.oii (Hill L'li'i!!/;/. — ^{. TiOui< group- near Iluntsville, Ala., where we obtained a eon.-idcralile nundicr of specimen^.

7//y/'.v in the collection of Wachsmuth and Springer.

Iiiiiiiiil.s. — This species is readily distingui.xlicd from ^1. SJnimanH by its smaller si/e and iccuudicnt arms, and from ^I. Wtirlliini hy the <lilYerent form of the calyx and the mueh smaller nundjcr of acces.sory pieces of that species.

The arms of this species were appurontly immovable, as is indicated by

102

810

THE CBINOIDKA CAMEUATA OF SOUTH AMEIUCA.

i

i

the structure of the vcntrnl disk, in which the covering platen of the different arras for (juite a distance are suturally connected, so as to prevent moiion. It is further shown by the deep impressions upon the surface of the dorsal cup, whicii evidently originated from constant pressure of the arms upon the plates in the growing crinoid.

I

1k

INDEX TO AUTHORS CITEP.

.\;.'assiz, Ali'xnii.Icr, L'S, 4:», J", .".1, 1 U.

AgtHsi/,, Loiii.s, 1 1, G17.

Aj;iiiol!i, 1 1.

Alliiiaii, G. '., -JH, n;).

Aii^'.liii, \. 1'., ;;ii, riK. or.', 2^0, xw, a.ir).

Aii'liii, I'liDinas, mill 'I'Iioiiuih, Jr., Ij, 22, W,),

Ilanit, Will. H., 21, 321, ;!2.">.

Itaiidis, C, 28.

llalli.T, !■'. A., 22, 31. ;i2, .'IT, .Vi. (;7,7rt, II I,

115, 120, 127, 12'J, 132, 130, 13«, l.W, li7-

10!. Itill, !■'. .1., 2H. Ilryiicll, K., 2.1.

l!illiii-M, K., 21, 110. 177. 27:1.

l!illiiij;s WaltiT K.. 21. 137. l;t8.

liliimriilincli, .1. ]•'., 12.

llioiiii, II. (;., 2'.i|.

liuc'li, Ixiip. voii, 17.

limy, II., 2M. -iM. O"., I. ".3.

Cai'iH-nler, 1'. Ilfiboit, 22, 27, 2H, 32, 1."., 47,

4!l, .')0, Til, .■>2, :>3, :.l, 02, 0'.», 7", 80. H."..

hit, '.111, III, 112. Ill, 103, 101, lO.-i, UW, 111,

112. 111. ll.-i. 117, 120, 111, 111,110, IIH,

2.10. C'nriiL'iiti'1% Win. It., 22, 2x. 1 ID. Cassnlay. S. A., IH, 300, 307. CliaiMiian, K. .1.. 21, .-.O. Clarke, J. .M., 2'.ih, 7.">2. Coiiiail, \x.

('ill >l"'ilaiiil, fi., 13, 22, 230. t'livicr, t).. 12. I Kile Chiaji', II. Dujar.liii anil IIiipi', IS, \f<\), 101, 210,230,

i;ii;.

Kiclinal.l, K., 23. Ktlii'iiil^o and CarpiMikT, '.U, 111). Ktlii'iiilfio. .Ir., K., 23. Folliii.'ili, Otto, 23, 2111.

Kraipoiit, ,1., 2.3.

Cciiiil/.. II. II., 210.

(loi'lto, A., 2)H, 01, H2.

(;.il(lfiis!., (i. A., 13, -.'3, 33.'), 017.

(iivplT. H.. 2H.

(iii'iiMl. .1. (1.. 22, 237.

(lioninuli, ('., 23.

(iiicltanl. .1. I-:., II.

Hall. .laiii.H. l«,20..'-iO. 00, 112. IIH. 1113. 237,

202, 2H2, -JX't, 2X11, 2110, 2111.311, 3-JO, 3.!.'i.

310, 307, 3M1I, :i;i7, 41.3, 42M, l."iii. 470, .'iiin,

.■)20, •)7."i, .'iH7, 0112, 013, 010, O.jj. GOD, 73."). Hall ami WliillicM, Oi'.i'.. Iliiiili'. (i..l., 7I.S, 7.M. lliiHiiijicr, W., 1 1. Ili'iisiiijirr. ('. I'".. 1 I. .laikfl. Otid. 23. .jl. .Ii'lTii'yH, .1. (i.. 28. Ki'vt's. C'lm8. It.. 7113. Kiiiiiipk, (V. mill 1.0 Hon. 11, 17, 21, 23, OS,

77. WO. 210. 2.30, 2114, .335, 041", 757. I KiiiiiHi'li, H., 23. l.miiai'C'k, .1. It. (U'. 12. 1,1'iiikail. V. S., 27, 144. LiiiiH'. C, 12.

Loiiul, I'. lU'. 22, 53, 01, Olt, 117. I.0V1I1, S., 22. I.iiilwig. 11.. 2H. I.iilk.'ii, V. v., 22.

I.yoii nml CnHwday, 21. 2.".0, 775. 782. 7113. I.yon, S. .S.. 21. .53. 311, 313, 327, 321», 7115. i.yon. Victor W., 311. .Miiiit.ll, C, 14, 22. Mi'Coy. v.. 22. 2.1. 017. MiCliisni'V, .1. II., -liu. 434. Mcik, l'". ii., 22, or.. 272. 071. .Mi'ik ami Wortlu'ii, 21. •J.'.7. 238, 3.sO. 113.

431, 434, 483, 4.>'0, 551, 010. i;i 1, 035. 07;i,

O.lll, 7113.

Il

1 1

\i

I

814

I.NDKX 10 AITIIDUS CITKI)

1'

I

Mivtr. n. voli. -.M.

Mil'l.T. .1. S.. I-.', .•.L'd, .'■.v.. C.IT.

MiiiiT. s. A., L'l, ;i(i, 111, :>■>. (Wi, w, i;i. J7.'). iN'.i, r.'T, L'(i|,i(i:., ;ll.:.'17, l'.p:M'i;7, 2".'l, :'•■<.'. r.'ii, l«."i. I.H(!. .'iiil, .M7, .l-Jil, .'illi, f>7,><. .V.t7, (iltl, (■.,■)((, Ciji, ti(;;l, (Hil, 7ltt, ■.■ii, 777.

Millrr, S. A., niul DviT. ;i:l.s.

MilUi\ S. ,\.. 1111(1 Ciirl.'.v. .'IHI, liilt.

Mnll.r. .loll. II. a;l. tJH. HI, 117. 1 1'l, i:,-J,

r.H. -.".'I. iHii. .M.'i. iJiCi, (;i7.

.Miiii^trr. (iiiif von. 1 1. 2;l. 71i.l.

Miinhisoii. |{. I.. I I.

N.iiiii;iyr. .M., •J.l, :;;i, 17. '.>\.\K>. Its. lOJ. 11."),

1|N.

(h'lil.Tt. I).. 1':'.

Orlii^'iiy. A. .r. II. 111. till. 21(!, 017.

Ohiii mill Sliiiiniinl, IH, (171.

I'uihl.T, C. H.. 11.

I'iii'kitiMoii, .1.. i'2,

I'lTriiT, K., L'«.

riiillij.s. .1., II, -.>:', -J-Mk M.l.-i. r,|7.

IVici. K. .1.. 17. 1111. ill'.. :.';tt;, iiic.

roiirtiilis. I.. V. <1.', 2N, .^H,

i,iii.Mistnii. F. A.. a;t, ;w.

Hiniriii'liirf.', K. X. S., L>l, ;tl('..

lioiiii.T. Ki-rd., l.">. Hi, \H, i:\, cs, 1 1(1, l«ii,

illi. -SMu -'(17. I'm, .•Id:', a.'Hi, 33."), ■1.S3, ,^s7.

(Ml!, 710. llnU: -J:'. -.'37.

iio>IUII-<. 11.

l>o«li V mill Ilari", 21. Sanillii ri.'«r. (1.. "-'3. Siirs. .M.. -.'I. .Savijiiiv. .1. C 11.

.Say, T., II.

Sriilolhriin, K. K., 13.

.S(liiilt/>', I-., •.'!', I'.l, (ill, i'M.

Si'li«ii).'f.'i'r, A. I'"., li'.

.Scilt;\vi('k ami .Miiicliison, 1 I.

.Sliiiiiiaiil, It. !•'., \H, 2N(I, 7"'2.

.SoHiTliy, (i. n,, II.

Slciiiiii};i'r, A. F., II, i;!.

.siriiiinaiiM, (i., 23, .'111.

'riiiinipsoii, <l. v.. 1 I.

■I'lioiiisoii, .Sir Wyvilli', 22, 1'.), 111.

l'rmil.Hcli(ilil, II.. 23, .so.

TiooM. (1.. lit, 11711.

riiich. K. (».. 21.

\'o;j;t anil Viini.', 2.S.

Voll)oilli, A. voii. 23.

\Vaaj;.'ii. W., 23.

WailiMiiiilli. C, 22. 2.^ '.m, 111.

Waflisiiiiilli anil Sliriiij.'i'r. 2.'i. 21'), 2«, 20, .')!),

(13. 70. ;ni. Ill, 112, 113, lO.s, 1 ID, K)7, 171. Wa^'inr. H., 23, 117. WalliiiT, .1., 23. M. M. W.tli.iliy. A. <;.. 21, MC, 703. Wiiij^cii and ZciliT, 210. Wliiliavos, J. F., 21, 71H, "."il. Whil.., (". A., 21. 2.J2. 3(17. 131'). WliillU.lil. I{. r.. 21. 102, 3;)M, .i'J.S. WilliaMiH. ,S, H., 21, (10, 7ls, 7.")1. Woitlim, A. H., 21. (10. 207, 773, 77."), 7.ss. Vanili'll anil Sliinnaril, \S. Z.'iiKir. .1. ('.. II. /.ill.l. Carl von. 1."). '23. "i3. .M. (10, 01, ll.').

117. 1 10, 1«0, 101, 210, 207, 2«2, 330, 33.'),

(vm.

■ PM W» I

,JmJ»-

I ii ■ ■ "■ *"

it

GKNKUAL liNDKX.

Abaooorinui, .1(13. Aliiifiiiiiil SjMl.'in. |.|iilt'M of. 38. Aliiiiiiniiil griiwllis, VX,, ,-.17. (I'l. IV, II.'h !l 17.) " '

Aoaooorinm, ,Si;l>, 515.

amerioanus, 516.

Elrodi, 515.

Ai-iiiilUiifriniiH, 21(!, 21,s.

Iimijiniiiiiiin, 211).

AoroorinidaB, :,->, h;3, K)-,, \r,\^, 170, 803. Aoroorinui, «i), |.s,-,, hki, 805.

amphora, mx;, 808. (I'l. I.XXX, ih'n

lit.)

Shumardi, nor,, 806, .-soit. (pi LXXX

liu'". i-;i.) ' ' ' '

'iniw/iirinin, .SOU.

■ Wortheni, Id.-,, SOG, 807, uni). (pi

l.\.\.\, liu's. lOa, b.)

•Vilinal SyMl, plali's of, ;]x, 88

ActinocrinidEB, 7:i, xo, ii;,-,, i7((, 550, ■iliinncriiiilfx. |();i, .l;(i, ,-,ii). Actinocrinm, i.t, (i:i, s,3, m,-,, i.)o i-)) j.),, ;"H;1ii.^, in;., 11:1, ls.i.Aii.,;ii7,;;'^,;, 552; i'.'l, .j78, :,h<\, cm, ,;2(i, 720.

iiliiioniiin, 'ili],

iiyllojis, (!2.'^.

■ 'i'iiinli.i, :\7l.

■ iiiixibntr/iiiitiin. 110.

var. .//,(;„,,, .| |i_

■ — ■ iilificd, (;;!2,

(iiiiji/iora, tiH',

ilmji/ii!), ,'',2(), •|,^().

iintfrpiiw'fiiuin, (.IS.

iirtmpotus, .181.

Ariit)!ili, r,->\,

arrosus, 577. (P|. i.v, ligs. 7-,Sc.)

I Actinocrinm aiperrimui, 575. (PI LX iIith .X fi.) *■ ■

- (iflcfiiin, I't'iH.

- (i.tlrrinciis, .| 1 1 .

- hiliii-hhititiin, 127.

- /yAi(V(, i;2.->.

hrvi'lriiriiis, ,);!;l, :,;Jj.

- Iirruin, 'ill, • Jli'iftsi\ i'»;i7.

lirmi/cs, ■'1(12.

Ciih/i'ii/iiiilis, ;!ll5.

nihipsn, \H,\.

• fiin'rit, ^^H

Ciiruli, 121.

Cassi'iliiiii, Ik;).

i'((iiliviilii.i, |n;1.

cliliii'i.i, ri7l.

chouteauensis, 570.

Ila 1,.)

• C/in'sli/i .Slniiii. IIJII.

C/irinli/i ]1„U, 1U1>.

vldfiis, (i|2. '■//«), ;(ii;),

chiUii, .'V.IH.

fhljivilliis, ;i,S().

riittttiin, (',]H.

roiicarn.t, 1.S2.

c'liiriiiDii.i, .■)H2.

Co;)c(, 51)8.

corbiilh, 3!)0.

cnniicKhi!), .■ill. cnriiiiKrii.t Hull, \:m.

cnrniijorus I.iioii, .ILS.

r'li-DiKiliis, Id;}. Coreiji, ,")l(l.

(I'l. XI.VI, lijrs.

V'

//I

8ir.

(iKXKUAl, IXDKX.

Actinocriniu fiiiliinfin.'. Ci\\.

-aaphue, fl74. O'l. l.VI. life'. I.)

— - lUriifiiis, It'iW. lUliciitiln, (ii'N.

—— litHl'/l flllllK, lll.'l. llinfoilll'IIK, Mli'.l.

■ iliniiiiilliin, 'l.'iH, . liii'i'riji'wt^ .*».HM.

■ llililiritiltlitilhlH, Id'i,

- ilni'h, ;I7I.

ifliiimn. III !•

Vt'luhtH^ (iliO.

I ;7/.i'. Ili.'i,

(''(i7i(l/'/.i, ."il'.l,

^— vtu'cti'tSt ■l;tll, — ^ i.tii rjiliiK, mil.

Jhr,lli,.i, :,]j.

jiii'ill'iSilH, .'I'ilt.

t'iiHlrri, liOl.

iji'iiiiiii/DnniH, ll'J.

lllllllH, ClJ").

ijblliliis. I'lKl.

'r/«"/i/,, i.h;.

gracilia, 572.

•jt-.i„.i:^. .-is),

brifli'.hi, 568,

y/.,.,,,.. 11.-..

/,./(>.. I si.

— - viir. (/•/.I. I-<I.

- Uiiiiiliiililii, .'i.'i.'i. Iiiirilliiii'is, lldl.

/fiLSfV/llf'/v/wN, .'til'*.

- llll^'■(lll iii(.«. ii.'i.

illjIllll'K, .V.I I .

ififi-i^ininH. lldl.

— iiii'i'ii'tlim, :i'''i.

inK'nl/.t,,..,. (,:in.

jugoiui, 563. il'l I. IV. li.u I., I

hi'iiturfi-ititnts, .*il-*<,

A'diii'iH'Ai', 117.

1,1,11'IKl, I'.lll.

. /,„,,'i,rnl„s, l.-lil.

/,ii;,-.l. ;i.si.

himlns. :17-.',

/,,„•,«/„. .101.

tiniiihriKlildliis. Cms.

^■,•■•".9. r.:!!!.

loUtni 1 IliiU i. 557. ( I'l. I.l I. t:.

I.; I.IV. Hi;.;! ; I.V. li-s. l;i. I..)

M'l. l.VI. li- 1 1.1

III. .•.I'T.

(IM, I. II. 111;. 7.)

Actinocrinni h.'-iins ( Il'.rf/n/.i, .*i;7.

I, u-i II iiH, r.ii.'i.

— ^— luiniii'imli'lii, 112.

- liiiiij'i.i. i;ii;i,

— towei. 562 ,n. I.IV. li-. •.'.) i,i,-iii,t, i;ii:l.

maguiflcui, .•.>■>, 567. i I'l I. III. ilg. .i.)

iii'ilitlti, il'.ii'i.

vnr. iiiiiiiiiiiiii, Wi.

Virki, I'lMI.

mining .*i;l;l. .'kI.'i.

ittii*r*innifijih iiHin» VIU". «y""<»/;/( /. 'li'i'it

iiihHDiirli'iiKh, H'l.'t.

inniiili/'Dniiiii, .'liO,

iiiii/liliiiiiliiiil"'. 111".

vnr. irhiiiiiliiK, 1117.

,i,nll!,:„;,nH. .•lll'.l.

multiradiatui, |ii;i,555. (I'l. 1.11. li^;-.

;i c. ) mnltirnmoius, ■"••'•I. (I'l. I. III. Hi;. 1;

I.V.IIji. :l.) I'liniNiliH uf, .'iili'i. .

m>iiiihihi!t, WH'i,

Xiishrilh; l;).-..

viir. militnti'liiH, i'-W.

iimltilirii'lii'ihis, I'l'.'L'.

iitnlitttun, lIOl,

iihM'is. l.'ll.

(tpiis'iilus^ 1)1 17.

»C»i('('.v.S('//l".'l. IlL'l.

iiniiiliin, .V.I".

IIIUlllIK, •'ilH'i.

— i,„iiilliiiiis, ;i.si). imrrun, l.'i.'i. 177.

llllllll'llH, ll'iM, 170.

-. /»* iti'iiilns^ r.;i.'i.

jt'iiliiijimiiK, .">7ll.

I I'liiii.ifihiiiH. :;ii'.i.

— pernodnaua. 561. 1 I'l. I.V. ligN. Ja. li.) fifriiihln'osH^^ (l;i.s.

- Iiislilllj'iiniilii, VM, Iilslilhi^. ;I7M.

Illilllllllil.lili'.l. .'iN.S, ."I'.lll.

i l,l,ii,i,ii:.i,uis. Ill,

/i/»(H'W".i (lU'liiclii'il Mini*).

I iioci'lhiiii, I ■"it.

imh/ililrt.illis (liniiiiin. •.".M',.

Iiiihlihli-liiliis {.Willi I-). i'.H'i.

y./'iir/(/-.1<l/% I.Sl.

limlmnciilitli.'i, I'lMl.

'V,

".^

y

CKNKUAI- IM)i:X.

M

m^

^^-

Aotinoorinni itrtimieimh, 170.

— — iiiiii'dtiin, fid:),

■ iii/riimiil'iliin, 612. — — fi^fi'i/nniiii*^ 4.'t7. var. riiilii, \M.

' f/Hftth'l.'<fllllUltf ."iMM, .'illO,

iliiitleriiiiHiiH, (1111.

var. Hiiliifjiriin, mil.

</iiiiiiiii(iiiiiiiliiiii, I''*, 120,

tjuitiifHi'ln/nis, ItiO.

rdiiiiilDiiin, UK'.

fiyiilin, ti.lH.

lUinlhl'ilrlil'illlIM, :\HH,

nliriildtilK, fill,'),

riiliiiiiliiH, {'M,

i'ikIi'h, fi'MK

tcitulm, 559. (I'l. I.V, l1«x. ycu.)

.ii- II I J, I IIS (Hull), .■)«;).

niiiljftiin ( Mail r), (dotachi'il I'oliiiiiiin),

— ■ — UTiinin, uM.

ni'ilitlinmin, 'ih't,

— ^ Kniili'iiiliiiliiK, L'Ml).

.ifiiiin'ii.H, ."I'.l".

ni'.i'iiriiiiiliin, (il.'i.

Si/linifint\ ."i.MI,

niiiiilin, ;iHi'.

SIHUOHUSf 'AH'i.

sin'i'fimiin^ (>;W.

niiiiiiilii'nchiiihin, .'p'.ll,

Sfu'ltnsufim^ I T'*^.

.tlihiiilriiliiriilnn, {'<\'^.

atellarii, ln'.i.

snhiiriifi'ilfiis, I7<i.

niiliiviiiiillln, ;ii;',i.

ttiihtni'hiniihis. \\'A\,

Kiiliiimlironiin, (i:l.'I.

siibrpiitrifosiiH, .V.l.'l.

Kiiliri-litiKs, .im;!. ■i;i.'5.

1*11111 iiipfrieiin, '177

fl'li'llilisrlis^ .'piiil, .VU.

liiiiitraili'ilus (/lii/l, ISOI, lint is'il

tenuisculptns, 'i."!.'!, 571, ."i71, lioii, C-j

(I'l. I.V, li^'s. Ill, h.) Iliiillii, IK) I.

l/lOllli.H, (101.

^/.i7m, (111.

Ihiiiis, (KLI.

thuliis, iVJt'i.

triacoutadactylut, oj.5.

Actinocrinui tnVni-iih, ir,M, I7(i.

trijugU, 576. (I'l. I, IV, llyi. la. h.)

h-iiinihi^. |i;7.

tuberculoiui, 573. (I'l. I.I I, llgH, Ha v.)

- liirliiiiiitiiH, .'I7i'.

vnr. rlii: iim, ;17(I.

itiiihmiiiiii, (ii'^

. iiiiifiii'iniitmi, 'I'll.

- — iiiiironilii, KlH. — — iiiiiHjilmin^ -Id?.

II fill I y .'i.'i.'i.

■ iiriiiifiii'iiii'M, 117,

I'lltlilim, !iK-i,

I'l'llfl'l'l'iiHIISt .")'.>.*l.

var. fiiiifiViiliin, .MO.

var. iiiliriioiliiiK, iV.iM.

var. vilifiiliiliin, ."I'.l.i.

• VI'ftll'lliU'tHIII*^ i."l(l.

verrnooim, 558, MX. (IM. 1,11, ti};-t.

2a <•.)

riiilirilK, .'■(.'i.'i.

riml'liiltis^ ^I'M).

U'ltrli.iiiliitlii ( W'liilo, IStW), ."i.VJ.

( Wliili, l.s.su), anl.

- H'A.Vi /, ■'■)-j(i, i'lyo. ]\'lii>jiilili, :rj->.

Yiiiiil.lli, .111.

.Irliiiiii'ilril. IC.

Actinometra, '.)'.). 212.

.\il-aiiilnil:nT:il (ir siilc-iiioccM. M, 10(1.

Agnricocrinua, Kil, ;ti;:>, i;)i. Is|. 486, .^.sd.

- americanui, 1n7, 488, !«;». (I'l. Xl.ll, fl;,'s. la-L'li.>

MIC. tuberosui, 489 (I'l Xl,, lij,'.

•1; Xl.ll, ilfj. I.-)

bellatrema, 506. (I'l. Xl.l, lifin. la-.l.)

var. major, 507. (I'l. XLI, lli;. .I.)

— ]tiii!ri. .^(l.•^.

brevis, .''ill. (I'l. XXXVIII, tl^rs.

bullatin, l.s'.i, i:i;i. (i>i. xi.I, lifjs. 2ii-(l.)

— — I'liiiiiti'iiiii'ii.'iis^ .'(((."(.

conious, 601. d'l. XXXIX, lli:w. 7. m.)

convexus, 508. i I'l. XXXVIII. IIlts.

1m. I).)

Coreyi, .MO. (I'l.

cnrni,jiifii/i, 'i\-2,

crassus, 499, ."ido.

2a, t.; XI., n^'. 1.)

ii'i'iiriiin, .j(i;!.

ili.i.'iimUis, iHH.

XXXIX. Ii;_'s la, 1 1.) (.I'l. X wXlX, llgs.

103

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Sdaices Corporation

23 WEST MAIN STREET

WEBSTER, N.Y. 14580

(716)873-4503

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818

GENKUAL INDKX.

AgaricoorinuB elegans, 500. (I'l. XL, figs. an, b.)

eris, 481.

excavatus, 4Si), 491. (I'l. XXXIX,

figs. 3-.^)

flsoellus, 512. (PI. XXXVm, (Igs.

3a-c.)

tjcometricim, TiOH.

riermaiiiis, itOo.

Gurbi/i, -lit').

— - gracilis, 513. (PI. XLI, figs. S.-i-c.)

hclke, 481.

imlinnensis, iO').

inflatus, 502. (PI. XLI, figs. Ki-d.)

Maradantsi, IDM.

nodosns, inn, 493. (Tl. XLIII, fig. It.)

nodulosus, 497. (Pl.XL, lig. -' ; XLIII,

ligs. Va, b.)

var. Macatlanisi, 498. (PI. XXXIX,

fig. 6.)

ornotrema, 500.

j)('»(r(;/OH».t, I'.l.'i, 4!>5, 500.

var. C'jdiv.vv.s', 508.

planoconvexus, 503. (PI. XXXVIII,

figs. Oa-c.)

pyramidatus, 512. (PI. XXXVIII, figs.

4a-5c.)

Sampsoni, 50."). (PI. XLVI, fig. 5.)

splendens, 495. (PI. XL, figs, la-c.)

!<jiriiiijefi\ .")10.

stellatus, 508. (Pi. XXXVIII, figs.

7.1-c.)

titberosiis, 490.

Whitfleldi, 496. (PI. XLII, fig. 3;

XLIII, figs, .sa, b.)

Wortheni, 4.s.s, 490, 493. (PI. Ill, fig. 22 ;

XXXIX, fig. 9 ; XL, figs. 5a-(l) Agassizocrinus, 17, 45, ,59, 145. •• Albatross " dredgiiigs, 28. AUagecrinus, 28, 78. 87, h9. 92, 150, 172.

Carpenteri. (PI. VIII. fig. 11.)

AUoorinus, 124, 2(15, 2G7, 306.

Benedicti. 308. (PI. XXTV, figs. 8a. b.)

typus, 307. (PI. XXIV, figs. 7a, b.)

AUoprosallocrinns, 3r,i, 406, 414, 4.'iO.

conicus, 407, 431. (PI. XLII, figs.

14a-c.)

(Icprcssus, 407.

eucouii.i, 407, 4.30.

Ourleiji, 407.

Altoriiate airangcineiit of parts below radials, GO.

Ambulaora, .35,99, 100, 101, 120, 155.

of Cnnicrata, lUO, 107, 114.

of Kistuluta, 99.

of Ichtliyocriiiuliu, 101, 123.

of Larvifonnia, 101.

of Recent Ciiiiolds, 101.

Ambiilacral canal, lUO. Anibul.aeral plato.s, 35, 101, 119. Anibulacial skeleton. (PI. IV, fig. 0 ; PI. V,

figs. 1 ami 10.) Ambiilacral vessels, 3G. Americanus group, C8G. Amphora, 58G. Amphoracrinus, 85, 454, 483, 48G, 550, 554,

586.

anierifitnnn, 488,

hellalrema, 500.

coDcarus, 482.

divergens, 588. (PI. LXII, figs. 5-10.)

var. iiiuItiramosHs, 588, 590.

pj'cnratiiii, 491.

Oilbertsoni, 5m7.

injlattis (Jlall, l!^(!0), 591.

inHatu.i {IliiU, ISOl), 502.

jerseijensis, 587.

jilanobasilis, 588.

■ pUwoeonrcrus, 503.

(jitiiilrinpiitus, 588.

spinobrachiatus, 591. (PI. LXII, figs.

1-4.)

snhturhinatus, 4(10.

viminalis, 587, 690. (PI. LIV, fig. 8.)

Anal plates, 17, 33, 105, 124, 139, 147, 105,

304.

development of, 131.

• — - special or first (PI. X), 34, 125, 147.

Anal tube, 35, 134.

abnormal growths of, 135. (PI. IV, figs.

9-17.) An-ambulacral plates, 35. .\ncbylosis. 37. Ancyrocrinus, 45, 50. Anisocrinus, 77. Anomalocrinus, 41, 57, 07, 71, 78, 110, 130,

l."i8.

caponiformis, 740.

Antedon, 82, 147, 153.

Pentacriuoid larva of, 152. (PI. VI, figs.

13-15.)

regalia, 107.

rosacea, 04. (PI. VI, figs. IS, lo.)

/

t

T

GENERAL INDEX.

819

4-

Anthemocrinus, 77, ^iri.

Anus, 21, :!."), 124, KM, 139, U,5.

of Carabocriuus, 137.

of CupresBocrinus, 137.

of Cyathocrinus, l;!7.

of Haploorinus, 91, 137.

of Hyocrinus, '.)!.

— — of Ichthyocrinus, 138.

of Fisocrinus, 13C.

— - of FoteriocrinuB, 137.

of Symbathocrinus, 13T.

covei'Oil by a (iastei'opocl, 210, .500, 701,

703. Aoroorinus, 3fi2, 470, 1^7, .517. canaliculatus, 475. (PI. XLV, (Igs.

C.a, b.)

Cas3edayi,483. (PI. XI.H, flu;s. 1 la-12.)

concavus, 482. (PI. XLII, ligs. 13a-c.)

elegans, 480.

helice, 481. (PI. XLV, fig. 2, t,.)

immaturus, 471.

parvibasis, 473, 477. (PI. XLV, ligs.

3a, b.)

parvus, 477. (PI. XLV, (Igs. 11a, b.)

radiatus, 472. d'l. XLV, lig. 1.)

spinosulus, 478, isi. (PI. XLIII, fig. 4 ;

XLIV, figs. Ha, b.)

subaculeatus, 476. (PI. XLV, flga. 7a, b.)

Apiocrinidte, ri3, TiO, 6'), 117. Apioorinus, 13, 10, 00, C.i, 117, l.")2.

roissyanus, 24, 1 17.

Archieoorinus, 119, 17.'), 21.5, 249, 253.

desideratus, 257. (PI. X, figs. 4a, b.)

lacnnosus, 2.51, 255. (PI. X, fig. 1.)

innrijiimfiiK, 275.

microbasalis, 256. (PI. X, figs. 2a-c.)

prhftis, 27."*.

pyriforniis, 255. (PI. X. figs. 3a, b.)

sciiliiliis, 251.

Armlets, 34, 82, IGO.

Arm opoiiiiigs, 311, 8G.

Arm platos, or " f rcG brachials," 33, 73.

Arms, 33, 73, 88, 155.

biserial, 34, 7.s, 1.55, Ifll.

imiscrial, 34, 'iK, 155.

paired, 8(1.

commence at, 09.

mobility and mode of union, 87, 155.

mode of brandling, 75, l^i, 80, 155, 101,

304. Arthracantha, 741, 747.

Arthracantha depressa, 751. (PI. LXXVL

figs, .'la, b.) ithacensis, 747, 749. (^Pl. LXXA'I, figs.

la-c.) punctobrachiata, 750, 752. (PI. LXXVI,

figs. 2a, b.) Arlirh'S hnwhiattx, 17. Artioulata (W. and Sp.), 20, 33, 149, 152, 154,

109.

(,L S.Miller), 13, 152.

(.loh. Jlrdler), 15, 152.

(Zittcl), 23.

.Vrlicnlation, 37, 87.

Arliyilosa, 153.

.Uti'i-ia, 12.

Asteroblastus, 140.

.Ulcrnci-iiois (Jfihifiter), 292.

Asterocrinns (L>ion), 292, 791, 793.

■ cajiitnlis, 794.

mmiianns, 795.

Antracrinoidea, IC, Aslrocriiu'tes (Cumberlnnrl), 292. A.itrocriiiiti's {Cnnrad), 292.

jiaclii/dacli/liis, 290.

^Utmci-iiins (Ether, and C((''i).), 292. Adropoiliru 047. Astylhhi, 10. Asti/Jocn'iiiis, 17. Astylocrinidee, 172. .\symmetry, 140. Atelestocrinus, 132, 148, 159. Aulocrinns, 138.

Agassizi, 138. (PI. VII, fig. 9.)

Axial canal, 33, 30, 45, 100, 140.

Axial cords, 30.

Axillaries, 34.

Baerocrinns, 72, 131, 14.8, 158.

DalanocrhiHS, 207.

scuq^ii.t, 208.

Barrandeocrinus, 302, 484, 485.

sceptrum, 485. (PI. VIII, fig. 1.)

Barycrinus, 41, 45, 82, 132, 100.

liiisaHa, 15.

li.asiils, 15, 17, 27, 33, 52.

anchylosis of, 57.

cvolntion of different, 54-50.

inferior face, 158.

orientation of, 57, 153.

orientation in Blastoids, 57, 153.

outer face, 158.

upper face, 37.

r

820

GENERAL INDEX.

Base, 33, rr2, fifi, 152. Iii|)!iitite, 51, ;")().

lit'xiigoiiiil, i(ir>, jiO;).

pentiigoiml, 1(J.'), (il5.

qiiiKliiparlito, .VI, ofi,

tiii' irtite, .VI, ,')(!.

Bathyp .nus, 11, (>;!, 112.

aliliiclieiisis, 05. (I'l. VI, fig. 10.)

BatocrinidsB, 70, hi;, 124, 105, 170, 361.

liatocriiiites, 77, MO, .'501, 30(i. . Batocrinus, 77, 109, 115, 120, 301, 366, 113, 551.

ubscinsus, 431.

wqiialiilis, 3(il».

ffiqualis, 371. (I'l. XXVIII, fjgs. 5, 0.)

(pijiiibmcliiatiin, '1 10.

var. nlattis, 411.

aijitatus, 451.

altiuscuhis, 409.

aialreirslamin, 433.

aspratilis, 380.

(istcrhcus, 441.

bi.ilimckhititi!, 409,

bilii'-bimitiis, 427.

Blairi, 401.

— ^ booufilk'nsl.i, 422.

— - biiihns}iii, 444.

Calvihi, 373. (PI. XLVI, figs. Ha, b.)

C(tli/i'iih)iih'S, 395.

cah/fidus (indotoi'iniiialile).

cantonensis, 383. (VI XXVII, (Igs. 7a, b.)

cariai, •14.'<.

ci^ssc'ihtinnDiK, 412.

chin'iji'riis (iiidctoniiiiiable).

rlu-Iiii, 398.

Clir!.sfi/i, '00.

clypeatus, 380. (PI. XXVII, ngs. 8a-c.)

mmjiarilis, 380.

C"W.;,/(s, 399.

critv-Jonlivillensis, 417.

Dari.ii, 424.

th'coris, 420.

iliiii'oi(.leH.i, 309.

illvah's, 425.

iloilecaddctyliis, 432.

)lon'i>, 371.

exconus, 430.

footiix, i\H.

JhiinuKiin, 3li9.

(IPmmiJhi'iiii.i, 419.

Gurbiji, 42i;.

Batocrinus grandis, 43, 381. (PI. XXVir, (Igs. la, b; 2a, b.)

(Im-kiii (*■. ,4. Milkr), 422.

Oitrlcyi (Kuwk'y uuil Hare), 428.

Iliiiji'ii, 415.

icosidactylus, 307, 368. (PI. XXVII,

llgs. 3a-c.)

iitiliitneusi.i, 415.

iiijkit'is, 414.

inoninlim, 380.

irregularis, 369. (PI. XXVII, flgs. 4a-c )

— JiichikIks, 451.

— KoiiiiicJii, 447.

— Itvtns, 375.

— hiijHiicubin, 453.

— laura, var. 135, 384. (PI. XXIX, figs. oa-(l.)

— lepidi.,., 372. (PI. XXVIII, figs. 2, 3.)

— kiwonia, 401.

— k'liriimsln'.i, 135, 442.

— Lord, 412. — ■ li/oiianuK, 427.

Maobridei, 376, 378.

• mar inns, 439.

malutii, 39G.

meiVocris, 422.

■ moiitijomi'i-i/Piifiis, 428.

mnndulus, 382.

jV«.s/n'/ft«, 435.

var. siiblradiis, 43G.

)ifij!ecti(!<, 394.

obkitim, 431.

pojiilkitiis, 380.

jiinlillifurmis, 437.

pistilhw, 378. (PI. XXXI, figs. 4a, b.)

— jikiiiodiscHS, 411.

— poculum, 378.

— jiiik'fu'lhis, 424.

— i>!/i'if'>rniis. 437.

— quasillus, 372. (PI. XXVIII, figs. 4a, b.)

— rc»iibrachi((tns, 3.S8.

— rotadentatus, 374. (PI. XLVI, fig. 7.)

— mliiixJiis, 431.

— sc>/jiliHS, ,384.

— nimilif, 382.

— sinuosns, 385. — • sinnositu, 385.

— spriycnensls, 410.

— subsequalis, 369. 7a-9.)

— snbcoiiicus, 430,

(PI. XXVIIL flgs.

,.j-<<-

GENERAL INDEX.

821

i

Batocrinus Skccii, |-.'8.

Imchi'.triis, -1 10,

tuberculatus, 379. (I'l. XXVIIT, ligs.

10a, b.)

turbinatus, 375. (I'l. XXVII, ll.us. r,n. c.)

viir. elegans, 376. (I'l. XXVIl,

flj,'.s. (la, 1). )

iiiiiiiiiensi'n, 121.

miiistii.i, l.'il.

ivriicuiliaiiii.'!, l.'iO.

ll'ticli.iiiintlii, .j.sl.

II7()7.-/, .11(1.

YiniiMli, .111.

Balemnocrinus, 11, 07, >i-2, 172. liilatoi'al symmetry, l.'it, 1 l.s, IGij. Iii^^cl■ial arms, ;U, 7.S, l.j.'i, IDl. JJl'iirucriiin.i, ,")."i2, "jo.i.

(inri.ius, ,')77.

bnllittus, ,')77.

ti-!Jiiip.i, 'uC, .578.

" lUake," tlrecV^iiigs, i.s.

ISlastoiilea, 12, 11, IC, .'lO, Ml, 1 Hi, 153.

C'ystiik'a aiic! C'liiioiili'a, ILi.

Botryocrinus, .S2. i:i2, IDO.

(lecadactylus, li;o.

Bourgneticrinus, l.s, c,.!. liracliiaU, :!;!, (iO, 7;f, 7<;. S7. Briii'hiiiiKil.

l!iMliii;j;loiiL'iisis group, 653. Cilfdhdcriiiiifi, ;!ll!.

y'.'//'''(.<, .'il7.

vai\ hili'rmeiliu', .'317.

lamMjsiis, 311, ;!20.

Ii,-iilu.i, nv.K

var. m>illilir<(, 31 0.

—— sijeciosus, .'i23.

Tronsli, 311, 31(5.

Cactocrinus, .s."), 101, 107, 120, .")r>0, 55.'), 075,

600, (12(i, (;:i.S.

pimuiK's of, (iOl.

Arnoldi, 022, 624. (PI. LVII, figs.

■la. b.) -clarus, 612. (PI. LVII, figs, i), 10;

LVIII, fig. 1.)

orelatus, 618, (120. (PI. MX, figs, .s, !) )

var. spinotentaculus, 619. (I'l. LIX,

fig. 10.)

denticulatus, 606. (PI. LVII, figs. r,a, b.)

ectypus, 611. (PI. LVI. fig. 10.)

extensus, 616. (PI. LVII, figs. G, 7.)

fossatus, 620. (PI. LV, fig. 12.)

Cactocrinus glans, 102, 625, C,2x. (I'l. IV, fig.

8; LIV, lig.s. 5-7.) limabrachiatus, 608. (I'l. LVIII, ligs. '.1,

10b.)

longns, 609. (I'l. LVII, fig. 8.)

lucina, 603. (I'l. LVI. figs 8, <.).)

multibrachiatus, 617, (118. (I'l. LVI,

figs, (i, 7; LVIII, llg. .s.) nodobraohiatus, 622, 025. (PI. LVII,

figs. 1, 2.)

obesus, 613. (PI. LV, figs. Oa, b.)

opusculns, 607. iPl. L\'I, figs. 5n, b.)

ornatissimus, 621, (125. (PI. LVII, fig.

3.) probosoidalis, 102, 601, 003. (PI. LVIII,

figs. 3-7(1.) reticulatus, 003, 605, 007. (PI. LVIII,

figs. 2a. 1).) var. ovatus, 606. (PI. LVII, fig.

11.)

sexarmatus, 615. (Pi. LV, figs. 10, 11.1

thalia, 604. (PI. LVI, fig. 2 ; LVII, figs.

12, 13.)

thetis, 614, OIC, (PI. LVL figs. 3, 4.)

Calamocrinus, 2.s, 10, 51, 78, 1»S), 117. Calathocrinus (vou Jleycr), 020. Ciihithocrihus iJfitll), 020, 037.

ultlirn, 032.

eroihis, 030.

hisndjitiis, 030.

CalceocrinidsB, 57, 72, 82, 131, MS, 157, 172. Callicrinus, 330, 335, 353.

aoanthinus, 356. (I'l. LXXXIII. fig 18.)

Beachleri, 355. (PI. LXXXIII, figs.

1 la, b.) cornutus, 357. (PI. LXXXIII, figs. 15-

17.)

var. ercnratim, 357.

murchisonianus, 358.

ramifer (?), 358.

Calpiocrinns, 52, 77.

CalyptocrinidsB, 43, 105, 170, 330.

Calyx, 33.

Cdli/.v iiiterrfiijialis, 105.

Camerata, 20, 33, 42, 00, 1 in, 151, 163.

analysis of families of, 170.

distribution of, 171.

sections of, 150, 103.

Camptocrinas, 741, 779.

cirrifer, 44, 780. (PI. LXXVI, figs. 12-

13c.)

I

82:2

OKXKUAL INDEX.

-h

Camptocrinus niyiloilaclvlus, 11, 779. (I'l. I, XXV, llgs. l---'l).)

CuinlliciihdK, 'M. Cdiihlmcriiiiin, l"t.

I'liltvrxoiii, 171.

7iV«7«()v^"»/, 171.

Carabocrinus, Ii;l'. Carpocrinus, ."il.').

simplex, .'pI.'i.

Caryoorinus, 1 1, 1 U'<. Cit.^liiii'M-rii)"", '.".12. CatilloorinidoB, h->. i:)l, l.'>7, 172. Catillocrinus, 1"), 72, 112.

Wachsmuthi, 72. (IM. VIII. fi','. 11.)

Cfiilrorniiii.i (Aii.^liii), ;WK (;i7, (!IH. Centroorinus (\V. ami Sp.), 121, 207, 2(;.'), 308.

m'tffii''n'iii's, ^AV.i.

pentaspinus, 309. (I'l. XXV, fins. l(ii\-c.)

iciiiiix.iif ii.ii.t, 2im;, ;!(is.

C'unti'oddr.sal ; see Tup stem-joint, o'i,

Ceriocrinus, l.'^'l, lfi2.

" ClialloiiLror " ilivdijings. 2.'< ; IJi'poi't, 27.

C'lianilieriMl oiiiari, :!r.. KMi. 140.

Cliarai'tors ill c'lassiHuatioii, ln^, 1 1'.i, l.">;i, HU,

lili;. C'liaracti'is, in oiio firoup worlliloss in otiiers.

i.m;. Cheirocrinus clarus, .') 1 .

Ci'iUdchirH, Hi.

C'iiri, ;i2, 41. C'lassifioation, 144.

of tlio .Viistins, l.'i.

of 1'. 11. CaipciUiT, 27.

of C'liapman, ;)o.

of J. S. Miller. l:i.

of .loll. MiiUoi', \r>.

of Neiiniayr, 2'.t.

of I'ictot, 17.

of Uoemer, Ifi.

of Stcininann, "0.

of Waelisimitli ami Spriiigor, '2'>.

of Zittel, 2;j.

C'loiiocriiin.i, 292.

Close suture, 37.

Comhtuata, 1.'!.

Coccocrinus, 'MK 02, HI, ('.12, ni.'i. 738.

bacca, 739. (I'l. LXXV, (ifrs. l.-.a-c.)

• rosacens, 7.i',i. (I'l. Ill, fig. 11.)

Codaster, IIU.

Codiacrinua, 77. C'li'liac eanal, UKl.

Cceliocrinuf veutricosus. (I'l. VII, figs. Uia- b.)

OiliirfiiiUH, <l .■>■").

miiciicii^, A')').

Color of specimens, 227.

Column ; see .Stem, 1)2,

Ciihiiiniiila, 10.

C'liiiitnlilht, l(i.

ComatulsB, 12, 11, 17, i'lO, 0.1, 59, C5, 70,

i;)2. Coujpound radials, 71, 1.")8. Compsoorinus, wo, 117, 2t;'J, 2H2, 302, 30.'),

516.

Harrisi, 517. (I'l. XXI, fijis. 8a, b.)

miainieiKsis, 518. (I'l. XXI, figs. 7a, b.)

CuiiiiCi'iiiiin {('oinjcrhilli's'), 100.

Cdu.inli'ihilhi'j appumliis. 111.

Convoluted organ, 102, 148. (PI. V, figs.

I 12.) Cordylocrinus, 79, 012, 015, 017, 735.

comtus, 730.

jian-ii.i, 737.

plumosus, 737. (I'l. LXXV, fig. 20.)

ramulosus, 737.

[ retiarius. 73.").

Corymbocrinus, 201, 2.s2. Costals, 13, 31, 71, 73, 77, 154. Cnstiilii. 15. 23. C'ltijlrdniioi'riiiiia, 010, 753.

jii'nhiliibu,'^^ 751, 77.5.

Covering [ilales of Ambulaera, 30, 100, 108,

112. 155. Crinoidea, 12. 30, M.5. 169. 172. Cromyocrinus, h(», 123, 102. Crotalocrinidae, 83. 103, ICI, 170. Crotalocrinus, 10, 81.

pulcher. (I'l. VIII. fig. 2.)

n. sp. (PI. VIII. fig. 3.)

rugosus. (I'l. VIM, fig. I.)

Crown, 32.

Clniiicrliiu.i, 282, 280. 292, 291.

hdiiilin'ihieiisin, 297.

hrrin, 301.

or)ial>i/i, 280.

lupus, 29 1.

Culicocrinus, 79, 83, 00, 92, 480, 042, 015,

735. 739. (PI. LXXV, fig. 14.) Ciijiilhirrinus. 730. Buchi, 730.

-imsMs'-'l-Z^^^

CIKXEIJAL IXDKX.

823

+

Ciipenrvcrinx.i mrrwjiitHs, 730.

• iiijlittim, 7.'il.

/(»■(•('.•), 7;!1.

matjiiijkm, 7;tl.

jil'lilili/rtiiiilin, 7;il.

rtntiffiirniin, 7^1,

slcViann, 7.'il.

.ilrliitiia, 7;!1.

Cupressocrinus, i:,, 70, 87, 111, 137, 111, l.-.x,

172. Cupulocrinus, 17'). Ciiiiihiicriiiiti'iK, •JO. CyathocrinidoB, 112, i;,,-), m-j, \-,>.

of l!iil/ii>r, l-,\)_

'/ /■•'"■ /»o-, 17.

Cyathocrinus, 13, 17, I,'), 77, 0'), OS, 101, ill, 111, 12.S, i;!(i, i;-,().

■ iimru:inal phites of, ',17, 17.').

or.ils of, 0.").

alutaoeug, uo, i rr>. (pi, m, (ics

fi, 7.)

brevisaconlus, Ofi, 137. (PI. in, fi". 2 ;

Vri, nj,'s. 12a, h.)

fdseidtus, 2HS.

Gilesi, II.-), 07. (Pi. Ill, figs, la, b.)

tevis, (PI. Ill, (ig. s.)

malvaceus, 07.

multibrachiatus, Oii. (Pi m, fijr. .i )

nodosus, ill), 137. (VI III, iig.'"3; VII,

li.u.-. ll.-*, b.)

planus, 17.

protubenms, 703.

ramosus, 1 (i2.

tuberculatns, 1 7.

ii'iihlrnnfiisis, 102.

Ci//ifvrriniis, {H'),

niniih'eiilalus, -18.5.

Ci/j)/mrn'nus, 200.

Go,!ii/i, 201.

Cvstiilci, 12, Ui, 30, 144, MG, 148. Cysts, 13, 502. ()//(im'itiis, 202, 204.

/(fi'i's, 301.

Dt'cnihrriniilir, 1 r)0,

Deoadocrinus grandis, 138. (PI. VII, n<'s

4, ;■).) IMtoitI jneces, 11.5. Denihocriniihi', 150. Dendrocrinus, 71, 78, I2fl, 128, 132, 159.

Casei, 128.

Desmidocrinus, 70, 280, 3fi2, 515.

Dlaboloorinns, 215, 249, 2<i2,

hieroglyphious, 252. (PI. X, figs.

5a-o.)

perplexus, 250. (PI. XI, figs, la, Ii.)

vesperalis, 251. (PI XI, figs. Ip, d.)

Diiimenoorinus, «o, 215, 2i;i.

Dichoorinus, 42, 44, 77, 70, 81, S3, (MC, 741,

753, 770, 781, m\.

angustus, 768. (PI. LXXVI, fig. 11.)

Blairi, 778. (PI. LXXV, lig. 3.)

cheslerensls, 802.

cinctus, 764. (PI. LXXV, fig. 5;

LXXVII, figs. 4n-p.)

roiisln'ctiis, 7s.s, 70).

conus, 770. (PI. lAXV, fig. C.)

roniif/criiii, 751, 7,s3.

coxanns, 763. (PI. lAXVr, fig. 0.)

orassitestus, 769. (PI. LXXVI, flo-s.

(ia-c.) °

missus, 801.

delicatus, 44,766, 7(5'. (PI. LXXVII,

ng. 13.)

diohotomus, 777.

etei/aiis {f.i/nn mid Cuss.). 780.

- expimsiis (,!/. iiuit I)'.), 750.

flcus, 774. (PI. LXXVI II, figs. Ifia, b.)

fu8iforinis, 754.

hamiltonensis, 772. (PI. LXXVI, fi.'

10.)

Humbnrgi, 777.

■ Huntsvillae, 773. (PI. LXXV. fig. 4 ) inornatus, 44, 377, 770. (PI. LXXVII,

figs. 12a, b.) lachrymosus, 103, 754. (PI. LXX\'II,

figs. 2a-c.) liL'vis, 765, 708. (PI. LXXVII, figs.

7n-c.) lineatns, 761, 703. (Pl. LXXVI, fio-s.

4a-c.) liratus, 759. (PI. LXXVI, fig. 8;

LXXVII, figs. 3a, 1).)

oblongus, 759. (PI. LXXVII, fig. 0)

ornatus, 762, 7ii3. (PI. LXXVII, fi.r.

G.) ovatus, 760. (PI. LXXVI, fig. 7 ;

LXXVII, figs. 8a, b.)

parvulus, 44, 778.

pendens, 774, 775. (PI. LXXVIII, fig.

1.5.)

pentalobns, 775. (PI. LXXVIII, fi^s.

lla-c.)

I

^24

(iKNKUAL INDKX.

Diohocrinus pisum, 7(!3. (I'l. I.XWI, 11^. .') ; Dizygocriuuii faoetui, 418. i.l'l. XXXHI

I. XXVII, lit;. III. I

plicatus, 758. ,;'l. I.XXNII, lliin. .'la, li.)

• iinrillniti, 71' (.

polydactylus, lii;i, 758. (\'l I.XXVII,

lll,M. Ill, ll.)

radiatus, 751.

soitulus, 767, 77l'. (VI I. XXVIII, li-.n.

I.ia II.)

sriif/iliia y/.i/iiit tiinl Cuss.}, 't'r2,

sexliihiilim, 7.1 1, 7NI.

siiii/'/i'.r, 7'.lll.

strifttus, 757. (i'l. I.XXVII. (iitm. lln. Im

Sllhsjiilllllusil.'i, 7.'ll.

superstes, 766. (PI. lAXVI, lij;. l-J.)

si/inmi'ln'nta. 1^*k

iririchi. 772.

Dicyclic. .'l:!.

Dicvc'lio Cniiiiiils. :>i, ,')M, 00. Ci".

Dtftfvlif't, .Ml, l.'»7, HJr'l.

J)iiiicriirriiiiis, l.s',1, IHI).

KplilU, 1112.

tlfciiiliwhihis, I II I.

irosi'/iir/i/liis, r.ll.

li/iil'iiniiia, 1112.

n/;,/,,/,i;ii'.i, 1112.

irti/'/nmcnsis. 111'.*.

Disroi.li'iis fjrcpiip, 7111. 713. Disk. 211. ;i.'), l(t.-i.

Uisli iiinliiilaci'ii, .'i.'i, l.'il.

I)i..t' ivcrii'S of ispt'iiimus. 1!).

I)i<l:il, .•17.

Dislifliiils (Dislicliuliiu. l.'i, .'il, 71, 7.^, lt7,

1(1(1, Ids. Distribution, •jcolnijioal mid tii'Ofjrapliical, 171,

IM, 2(i.'., 3(;;i, ."!.•. 1, (II.;, 712. .sii;t.

ilf,'. 12.1

Oorbyi, 426.

Ourleyi, 422. (I'l. XXXIV, tlj;. in.)

- iiidianeusia, 11.1.415, 117. (I'l. XXXIIf,

li^js. (la, 1); XXXV, lij:. :,.) viir. simplex, 110. (I'l. XXXIII,

li-. 7.) montgomeryensis, 428. (I'l. XXXIII,

li«s. ;!, •!; Xl.Vl.lij;. 1(1.) viir. unibrachiatUB, 429. (I'l.

XXXIII, llys. i'la-c.) mutabilis, 111, 429. (I'l. XXXV, flfis.

N, 11, 1(1, 11.) originariui, 111, 421. (I'l. XXXIII,

I1j;h. la, li; XXXV, lifiH. II, IT..)

vnr. adultm, 111, 422.

rotundus, 431, ■1.12. (IM. XXIX. 11^8.

;ia-l.) unioneiisia, 424. (I'l. XXX\', li^s. 10-

2(1.;

viir. divalU, 425. (I'l. XXXV,

li.iis. 21-21.) — ^Whitei, 419, 421. (I'l. XXXIII. Iif;>».

Kill. 1>, 11.) didactylus. 420. (I'l. XXX\', llg-s.

12. i;!.i Solatocrinites, 201, 304. DolatocrinuB, 77. 122, 121, 20.".. .^(l7, 310. .ill.

canadensis, 315. (I'l. XXV, li'is. 7a. b.)

excavatus, 321. (I'l. XXV, li;;. I ;

XXVI. fiLts. 7, H.) — glyptus, 317, ;!1H. (I'l. XXVI. li^'9.

2a, b.) — - ioosidaotylus, 319. (I'l. XXVI, li^'s.

.".a-il.) lacus. 311. (I'l. XXVI, fij;s. (ia-c.)

Dizygocrinus, .'ii;2, .■i'i7, :17I, 413.

andrewsianus. 433. d'l. XXIX, li;_'s. liratus, 319. ( I'l. XXVI, lig. ;).)

2a-il.) var. miiUilini, 319.

biturbinatus, 427. i:in. (I'l. XXXIII. Lyoni. 314. d'l. XXV. ligs. Oa-il.)

11,^'. '.•) I major. 322. (I'l. XXV. lig- .V)

oantonensis, 423. (I'l. XXXIH. fiL's. Marshi, 312. d'l. XXVI. lig. la-d.)

.><M. b.) I var. hamiltonensis. 314. (I'l.XXV,

crawfordsvillensis. 417. 1 llgs. 2n, b.)

decoris, 420. d'l. XXXV, (11;. 0 ) ! omnius. ;)1 7.

dodecadaotylus, ■i:!2. d'l. XXIX. figs. ' speciosus, 323. (PI. XXV. figs. la. I..~)

1 a-c.) euoonns, 11:1, 430. (I'l. XXXV. figs.

7a. b.) var. abseissns, 431. (I'l. XI.VI.

fig. '.».)

triadactylus. .Slfl, (I'l. XXVI, figs. 4a-(l.)

tubercnlatus. :!21. (I'l. XXV, flg. 3.)

Dors.al Clip. 33, l.'iO. i Dorsocfutral, 33, ll», r.l.

\

X:

NS^-Tr*-

GKMCIiAL lM)i:X,

826

Dorycrinut, Idi. 107, 121, ncj, 111, 484, Isi,

is7. :,:,\, :,>n\. (n. iv, iig. s.)

—— (iiiKrnus, 177.

riimiltciiliiliis, l.'i.'i, 170.

cuiiritriis, \,>'i, |Hi,

coii/rdf/oiiiis, 101.

cornigerus, 4.58, li;n. (PI. XI, H, (IgH.

0, 0; Xl.lll. lit;, .'i; XUV, llga. U, 7.) — — <le$iiler(iliiii, l(l;l,

rlrl)<l>l.1, I HO.

Oonldi, 456. d'l. XLliI, llgrt. •_', 3;

XI. IV, llgs, I, .-..)

hiimiitiiriin, 171.

iiifliitns, iCM, 170.

iiitermedius, 461. (I'l. XLIV, llg. 1.)

Ketliiiiijl, X'lX.

tiiiniliix. 'U\X.

mississippienBis, 455. (IM. Ill, llg. -'O;

Xl.lir, llg. 1 ; XI. IV. llgH. 2, ;i.)

viir. sjiiiiH/cr, I .'>.'>.

missouriensis, 463. (I'l. X 1,1 1 1, llg. 0;

xi,v, iigH. i;iii-i I.)

ptin'ihnsUf ■17<'1.

IKirrun^ '177, -171).

peniffus, -[M.

quinquelobus.460. (I'l. X 1,1 1, figs. 7-1).)

war. uili'rmeilhis, 1(11.

railiiiliis, 172.

Roemeri, 464. (PI. XLV, figs. l.">a, b.)

sphniHiihtS', -17^.

niilKii'iifriiliis, l'(\.

subtnrbinatns, 466. (PI. XI.II, (Igs.

10(1, li.) tn'conii's, 'ICiM.

unicornis, 468. (PI. XI.V, (Igs. 8i\-i0.)

unispina. 467. (I'l. XLV, Iig. 12.)

Eotenoorinus, 11, 121), 1.!.!.

simplex, 71.

Edriocrinus, IkisjiU of, .')n, 1 10. Eilwiinlsiierimis. (1 17. Eleutherocrinus, MO. Emeiliillain, iiO. EncrinidsB, h7, 117, ir,2. Encrinites, 12, 017.

Enorinus, 11, 11, d, GO, SO, 127, 133, i.Vl IGO, lf>2.

liliiformis, 11, SO, 110.

gracilis, so.

Entrochites, II. Epactocrinus grandis. s-3. Epascocrinoideii, 29, 118.

Kpi/yHMl, .Tl. '^I.

Eretmocrinui, ;i(;i, 3(;7, 37.'i, ;1mo, 385, 111, .-..il.

inliilhiK, 122.

oalyculoides, 395. (Pi. XXXIV, n^^.

Iii-l.) nodosus, 396. (I'l. XXXIV, lign. (!, 7, H.)

ciirii'ti, lis.

Clio, ;)7.-., 393, 301. (Pi. XXXVI, (Igs.

•ill, 1p; XXXVII, llgs. Oh, li.)

clcBlia, 398. d'l. XXXVI, llg«. lo, b.)

corbulis, 399, lol. d'l. XXXVI, llgs.

Oii-G.) coronatus, 403. (Pi. Ill, llg. 1-^;

XXXVII, llgs. 7n-o.) depressus. 392. ( PI, XXXNI, llgs. I In, b.)

t/t'inini/nnnis^ '111'.

granuliferus, 390. (PI. XXXIV, ligH.

.")n-t'. ) intermedins, 404. (PI. XXXIII, ligs.

2a-c.)

A'oiii'iirkl, 117,

leucosia, 401. (PI. XXXVI, llgs. 7o-o.)

ti/mniiiiis, 3m(!.

magnificns, 3(S2, 386. d'l. XXXVII,

Iig. 3.)

matuta, 396. (PI. XXXVII, llgs. On-c.)

V!ii'. iitleiiiiald, 307.

minor. 391. (PI. XXXVI, llgs. lOn, b.)

negleotus, 301. (PI. XXXVI, (Ig. 3.)

on'giiKin'Ks, 122.

preegravis, 405. d'l. XXXIV, (igH. 0. 10.)

ramulosus, 387, 300. (PI. XXXVII,

llgs. lil-.Kl.)

remibrachiatus, 388. (PI. XXXVII,

(Igs. 2a, b.) v.nr. expansus, 390. (PI. XXXVI,

llg. 1; XXXVII, llgs. la, b; XI.IV, (ig. 0.)

rugosus, 402. (PI. XXXVI, ligs. Oa-c.)

varsorieiisis, 421.

fmiciiilidiiiis, 100.

Erisocrinus, 21, 80, 123, 127, 133, 102. EiH'iiliiptnrnniifte^ 33(). Eucaiyptocrinns, 200, 330, 332, 353.

nniiiisiis. 330.

chiroffoensis, 312.

coelatus, 336, 339. (PI. LXXXin, figs.

5-7.)

c'celnliis (lioemer, not Hall), 341.

conicus, 330.

constri'ctus, 342.

1U4

i ^

\

820

OKXKUAr- INDKX.

}:j

EuoalyptOCrinOi eormiliiii, M.l'i, ,*)'>',

orasiut, .M, 343, liiii. (IM. l.XXXI,

llgs. l-l"l.)

— i/,T,.ri,s (//'(//), aiio.

deoorui (I'liillips), .■):17. (I'l. I.XXXII.

llg. 1.-..) deprewui, 349. (I'l. LXXXIII, (Ign.

Egani, 352. d'l. I.XXXII, tigs. U. I.'.)

— rllijilirHS, Mil,").

Elrodi, ;!.)«, 339, lilO. (I'l. LXXXI,

iigH. 7ii-i;).)

ercnvaliii, S'Mt,

ijieHiiii, Mli.'),

ijlhhosus, .'l»l'i.

CMfimi, a;).').

iwibj/l, .'3 1«.

inconspeotut, 346. (PI. LXXXIII, figs.

1. -i.)

titrh, SXt.

Lindahli. 347. (I'l. I.XXXII. flj;. !).)

magnui, 348. (I'l. I.XXXII, llgn. 7, H.)

iiiiimlin, 1137.

luislivlliiT, a:).').

obconious, 353. (I'l. I.XXXIII, Og. 1.1.)

ornatui, 340. (I'l. I.XXXII, lig. 10.)

ovalis, 344. (I'l. LXXXII, llg.s. l-(i.)

wuliis (/fall), 'Mi.

jiii/iiititsKS, 330.

J'hilUpsi. n.'l.'i.

proboBcidalis, 352. (I'l. LXXXII, fig. M.)

riiiiilj'fr, :VA'i, ,"i,"].S.

rosaceus, .'l.'il, ;W1.

rotunduB, 350.

splendiduB, 350.

siiIu/IuImsus, li'VJ,

Euoladoorinui pleuroviminui, 7i:i, 724, 721!. (I'l. I. XXIII, llg. I; I.XXIV, llg. 1.)

praonuntiuB, 726. d'l. I, Will. llg. 5.)

tuberoiUB, 728. (I'l. I.XXll, llgn. 3-lc.)

I''nirlni)iileii, 2.'l. I'.iicriiiiin, IM'.I, r,»2.

iiiliii<i(litili$, VJi.

Im-ia, 1 112.

iiiiii'ir, 1H2.

uniiihii, 1112.

— — i/iilii(/ii(iii</iiliin'», 11)2,

tprrioiiis, 1112.

veiiuilHii, 11*2.

Eugeniaorinidee, 21. .M. Eugeniaorinitet (.1. N. .Millci), |3.

Kdi/eiiiiirri'iii'lis (Hvinhiiier), II.

EupachyorinuB, 21, 4r), «0, 123, ICO, 1G2.

J'lin/dle, 12.

/•'im/iirocriii ii/tr, 1 .'lO.

EuBpiroorinuB BpiraliB, IMi, 132. (PI. Ill,

llg. r,.) EutrochoorinuB, 3(11, ,'ir,7, IOh, .Ji I. Christyi, 409. (I'l. III. llg. 21; IV,

llg. 7j XXIX. llg. (i; XXXII, llgtt. la-f.) var. trochiBous, 410, (I'l. XXXII,

fig. 3.) Lovei,412. (I'l. XXIX, llg. 7 ; XXXII,

llgs. 2n, h.) planodiscuB. 411. (I'l. XXXII, UgH.

■la. 1).) F.voliiliiiii of Crinoids, 100. Extracrinus, M, 01, 03, n'l. lMstiilata(W. iimlSii.), 20, 3.'., Ill, 117, lOO,

l.M, 101, 169. Fistiilitta (/Ifit/irr), 1,")7. Fisliilfitd (C/iiijini(iii), 30. Kixi'd Hracliials, ,'i,'!.

IfiiiiessffT, 33."i.

tuberculatUB, 337. (PI. LXXXIII, figs. I Kood gioovo, 30, KIO.

y-io.) jForbeBiocrinus, 77.

turbiuatuB, 351. (PI. I.XXXII, llg. 13.)' Agassizi, 77.

ventrioosus, 330, 341. (I'l. LXXXIII.' nobilis, 77. (I'l. VIII. fig.s. O.i-c.)

figs. 11, 12.) Wurtlieii!. 347.

Pralleni, 2111. Fri'c Hracliials, 33.

Eucladocrinus. 70, Kl, 101, G42, 010, C4.s, Oasterocomidffi. 141, LJ7, 172.

CO."). 719. millebrachiatus. lOl, 720, 72."). (I'l.

LXXIII, fig. 1; I.XXIV, iiga. 2-11.) var. immatnru8,722. (PI. LXXIII,

flgs. 2, 3.) montanensis, 710, 723. (PI. LXXII,

ng. .5.)

Gaurorri'iiiis, 17.">, PJ7.

amjuliiris, IHO.

cngnnliis, LsO.

mngiiijinis, 177.

AW//, 179.

spkndens, 1 98.

Gii:acnmia, 202, 204.

1

\

(!

UKNKKAI- INDKX.

827

^

Giintrriniii limrnaliit, 20,1. <M'iiiliil ciiiittl, :it>, KlO.

Oennseoorinui, :iil-j, Imi, 947, O.'il,

Ciiiie</(ii/i, •InII.

—^ cnnili/irii», .M'.l.

euoharli, ni'.i. d'l. XXXIV, fl}{. II.)

kiiiiiicldi'ii-iU, .■)l", S48, iVl'.i. (I'l.

XXXIV. llgit. II, IJ, i;). Gi'iwn'iiiii, ."illl. (ii'olojjlciil mill KL'())(rii|)liitiil iliHtriliiiliDii, 171,

iN.s, -ji;.'), ,')(;;i, .-i.-,!, (Illl, li'j, jso;!.

of the CilfiUTiilii, Ui;i.

(ii'i)liii;idil niiif;i' (if I'Mlu'oziiio CriiioiiU, IV'i. <lr(ilii;,'iiMll rciMI'il, Hi".

Oilbertsoorinua, ni;, \-2-2, ■.'!:>, 233.

oalcaratui, I'.iC. (I'l. XV, lln. "i.)

diapansut, 240. (I'l. XV, II^'h. Jii-d.)

fljoellui, a;}.-), 2;)H, 248. (I'l. XVll, (ij^s.

L'll-(1.)

obovatui, 2;)H, 241. d'l. XVll, lli?8.

•lii, h.)

reticulatus, 244. d'l. XVll, n;,'H. la, !>.)

ipinigeruB, -iXi, 247. (I'l. XV, (Ijjs.

.'ill-O.)

itellarii, :'1'.>, -J-.W. d'l. XV. II;.;. I.)

. tenuiradiatus, 246. d'l. XVII, t\g. ■\.)

tuberoulosus, 243. d'l. XVll, llgH.

.'m-c.) tuberosus, 239, 703. d'l. XV, (l^s. la. I) ;

XVI, n^'M. i-c; XVll, iij;. i;.)

typus, 242. (I'l. XIV, ligs. 1, 2, 3;

XVII, llgs. 7a, b.) Gissoorinus, l.v.i.

ObijiUtster, 17,'), IHO.

armosiig, 211.

liiiir/iitilKs, I'.U, l'J,5.

A>/H/'. 11)2.

inontittitft^ lU.'l.

i)critlciit<ills, H).'i.

var. in creliescens, 10.5.

- priilii)ir/)il(iri.i, 102. Gli/ii/astcriilrr, ISO. G/i/jiton-in!il(r, 17'), 180, 207.

Glyptoorinus, 11.(111, 70. Kl, li;i. 117, 117, 171. 107. 200, 2i:i, 267, 201, SlO, -lil.

angittarh, 100, I'CiO.

(in/iitiis, 2fi0, 2H0.

ariiwsiis, 211, 2110.

/fdcW. 177, IMS, 269.

basilis, 2(i0.

Carlei/l, 2C9, 282.

Olyptoorinui <-'i//'i'/'"», 177, 2('0.

daoadaotylm, hI, 200, 270. d'l. XX,

tljiH. la-o; XXI. Ilgn. In, li.) Dyeii. HI, 271. (I'l. XX, llgs. la-i'i

XXI, ;ia-f, (1.)

J)i/iii, var. miliylubiiiiiii, 271.

i'x/iiiii»iiH, 2tlO.

Jiiii/jriiilim, 2(iO.

- Fornihelli. 1.., (Ul, 17,'-., 267. (IM. XX, n«. M; XXI, iiB.:..)

ijlnhiihiriii, 2110.

yritPiliH^ 2(10,

//(irrlai, 200. 2H2. .1 17.

tiiiiiiKHiiii, 2."i,'i, 200,

lihiiiiio, 200.

- marginatui, 2.V1, 275. (I'l. XX, fig. 2.) iiii'dini'i'iisiii, 200, i'l 17.

ikiIiIHh, 212, 200.

Oiieulli, 177. 170, 200.

ornatui, 120, 274. (I'l. XX, llgs. Oa, b.)

/Hin-iis, 17.'., 100, 200.

I'lillerioiii', 174, 200.

jiliiiiiosiis, 200.

primis, lOM, 200, 278.

i/iiiiii/iicjxirllliin, 200.

ramuloius, 273. d'l. XX. Ilga. 5a, b.)

Sicliiirilsuni\ 171, 177, 271.

scntptiiSy 200, 200.

— Shafferi, 272. vnr. grrimmiii, 272.

— si/i/io)i(iltia, 211, 200.

— Bubgloboius, 171, 271.

— milmodosiii, 2."iO, 2C0.

Onorimocrinns, 138. Goiiiuslcroittdciiitiis, 231, 237.

JisceUiia, 21.5.

It/oixiniis, 210,

ohuftiliis, 211.

reticuloliis 211,

spinigcriis, 217.

lenuirailialns, 21()

tttbercitlosus, 213.

tiilierosHii, 230.

/i/piis, 212.

Graphioorinus. -14. fiO. 80, 128, 130, 133.

Oraphioorinns enorinoides, 80.

Growtli in Imliviilual, 70, 83, 536, C29, 652,

05 1, 080, 804, Quettardiorinns, 24, 61, 00, 117. Habits of Ciinouls, 48, 50. Habrocrinus, 70, 302, 515.

1

a

I

f

r>

il

■si

)

Sl'8

(iKNKUAL INDKX.

Habrociimin (inmliin, IIH, ia<i. lla.lniciiiiuH, 77, •.•i;."i. :'i;7, 387. - dUout, 388. (I'l. XXIV, Dk 1 )

— — ■ niHfiiifiiiiUM^ ;l-(.

pitniiilmui, 388, (VI XXIV, llgn.

:;it, II.)

Hftplocriiiui, ill, "'J, Hit, 111, n.'p, ',17, I;I7,

17 J. mespiliformli, h:i, h.'. (I'I. Ill, I1k«.

I -.'a, l>) IIi'ilii>|>li<'l'lrll-< ^'l'oll|>, 703. Herpetoorinui, 1 1, I.'iH, HeteroorinidsB. «:/. 17:'. Heteroorinui, II. t:7, 71, h-.>. IJii, l,"7, 77'.i.

belleviUemii, l.H,

ll.-x:uTiiii(l;v. h:\, iim;. Hi;), in.^i, l7o, tii.-,.

741, 7 1 J. H(i;l. /fi:r<irn'iiitt'», ire llixneriniilir. Hexaorinus, 7'.i, i!l7. 711, 744. 717.

Idlocrinui Immaturui. 806. (.IM. XVIII, fly;*.

lOll-C )

tenneiietnili, 3C6 (I'I. XVIII, ll)(. II.)

ventrieoiui, •-'•ci, 205. ( i 1. Ill, tin- I "> i

X\'lll, II^H. ',l||, h.l

Iiiipiiiiiiii:!, |.'>:', 160, 17'.'.

Inadunata, :'i;, :):i, :i.'>, 1 17, l.'id, 196, 1(1'.).

/niiiiii iiliilii, 1,1, liifi'i'i'iKlliiU, 'M, 71, I'M. liil'nilMiniilH, :.'i;, ;i;i. 98. .'>:l, til,

llllcllNlosiH l)f, .'I'.l,

i>r Agauizocrlnui. ,'i',i.

- - <if till' .\|iIi>(mIiiIiIii', (ill.

- ipf ('(lllllllullC, .'l.l, I, I,

- - (if Cupreiiocrinui, .Mi.

- - <i( Extracrinui, ,'i,i, ill.

i)f thu I'MHliilntn, :>h.

(if Iho Klitlivofiinlilii', ,'iH, fil,

- - (>r Millericrinui, ,Mt. ci.

Ill' Stemmatocrinus, .V.i. Leai, 746. (I'I. I, XXVIII, linn. I'.'ii. I'.)' Iimci' Hour of t.^'iiuii. il'l. V, flgs. 13-17.)

melo, 7l,'i. j Inli'i'iiiiiliiihiri'MU, 34, .'HI, lll,-|.

oocidentilU. 745. d'!. LXXVIII, (Ig. 10 » liitri-Mxilliiiirs, 35.

Iloxiiijoiial liiiHO, IC'i, lll!;l.

IliHidlll'llI, 1 1

Holupus. 11,01, 11:'. Homoorinut, I.'.. 7k. I.'U, 1,V.), Ifil.

acopariui, l.'>.

Hoplocrinus, 71.

HybocrinidoB, :,7, m-.>. lift. 1 17, Hi'.', 17'.'.

Hybocrinus, (17. 71. U",i, l,i:l, 1(1:'.

Hybocystis, 71, 1 I'I.

Hydreionocrinna. ."^o.

Hyocrinus, :<x, T^. '.U, ',(',•, 11"*.

bethellianus. (I'I. Ml. li'i. Ki.)

J/i//i'iiif/ioiri)iiia, 'M'2, i!35. ^— • ileroriit, O.'IO. //i//iiisriipn'iio!ili'(i, 20, 1 IS, Hyptiocrinus. is.-^, 200.

typus. 801. (I'l. XIX, (Igs. Oii-p.)

lIviMizygiil joiiitH, ;ll. H\. J/i/slricn'inis, 717.

. Ciir/ipiitiri, 7.")0.

Ji'/tt/ii/nrrin(irftif 'i'.l.

Ichthyocrinidae, 10, '>x, (Vl, f<7, u:!, 1:'.!, !.'>:',

i:>n, 17:'. Ichthyocrinus, 77, 117. 1,^2.

li'nsiiliirh/licrlnllPS, 2(W.

Idiocrinus, is.'^, 202.

InlrHinii'liiaU, 34, |o.'>.

liitii(li>liolialH, l.'p, 35. lo.'i.

Intcnial cavity, IO(i, l:'0, 140.

liitci'iKiclal JiiliitH and IiiIi'I'iioiIch, 33, lo,

1,V.. Iilti'i'lialiiiiMS, l.'i, 35. 10."p. Iiitrrradial plat.s. l.'i, 34. lO.'i, CiKl. of Cyathocrinui, Oft. 1 1 1.

■- of till' Urli'ni.Tillillil', loft, 110. 171.

of till' lilioilocriiiida', loft, 217.

of till' I'latvc'i'iiiiila', ft 1(1.

locrinus, (I.-*, 71, 7h, 12(1, i:io, I.');). I.'.H. LampterocrinuB, I7.'>, Ihh, 207, 211.

/;///((/»,«. •2»><.

/njiriis. 20M.

teimesieen«i», 208 (I'l. XIII, \]gn. lOa-

d.) I.arvii of ('otnatnla', infi'aliasals In, ft I. I.ai'vifonnia, 2ft. 72. m7, 150. I.'.l, lft2, 169 lecanocrinus Ililliii^Ki, l.'t'.i.

macropetaluB, l.'io.

LepidocentruB eifelianuB, 7IM.

Lilirn'ii, 1ft.

lobocrinus, ;!ftl. .'1(17. ;i7."., an:,, 434.

sequibrachiatus, .')7."i, 440. (I'l. XXIX.

(IjiH. 8n, b; XI.VI. li^s. (la. h.)

— elongatus, 203, '200. (I'l. XVIII. ng:s. var. asteriBcus, 441. (I'l. XXIX,

8.1-c.) I figs. Ha. li.)

\

-f^

(iKNKU.Vr, INDKX.

8'J9

loboorlniu Hftjeri, 44S. il'l. X\X, (!«<. 0, 1(1.)

Mnrlacrlniu /nnin't/fifn/hdi, 2iirt.

plumoiun, '.'h:>, 384. il'l XMII, l\v:». Infliitm, 444. i I'l. XXXIV, iI^^h. ih,,, i,.) i;, ;,) longiroitrli, 443 I'l. XWIIl, il«». rnmoiui, 384.

Inc.) titmiililiillt, ■>>*•>.

NaihvlllsB, 439. . I'l. XXXI, il.r. I.) Warreni, 383, d'l. XXII, ll..<. I.)

viir. iubtrnotui, 430. il'l. XXXI. .U.ii.sii/,inrriii,'im. 7.:m,

HK". ill, I'.) Marsuploorlnui, ll, T'.i, lnM, III, ll-<, ■-''■I,

pyriformii, 417. d'l. XXXI. II^h. Iln-c.i

robiutui, 416. il'l, XXX, iI^m. >*», li.)

ipiniferui, 419, d'l. XXX, lljj«. 1 1, I'.'.i

Yjimlolli, 441. (I'l. XXX. IIijh. 7ii, li )

I.iiiiso .^uliiii', :17.

Lyrioorinui, ml, ■.>i.'), •2\<.k 361, ;imi).

- — daotylni, il", Jiil, 363. (I'l. XI, Hhh.

.'ill c.)

- — moliMa, -.'i;, iM',:', 363. d'l. XI, (Igit.

•In-f.) Hnil/iiilli (/l(iir), 2.11.

lriil/ili/!ll (Millii), •.'.'ll.

nritlpliis^ 'J.'il, -I'l'J.

Microciinm, :n!l, 'M\~. 446.

-carion, 448. d'l. XXX\ II. ll'.-. h.-)

gemmiformli, 449. d'l. XXXVI. Wi.n.)

Koninoki, 447.

jucundui, 481. (I'l. X\X. I1l;h. in 1 1.)

Iftguiiculus, 453.

verneuilianus, I(i2. I l.i. 450. i^l'l.XXX.

ii^'M. I."), h'n 17, |M.) Maorostylocrinus, 'JCI. 285, .VJI.

fasciatus, 388. d'l. XXII. IIl'. VX")

fmibraohiatuB. 291. d'l. XXII, W'^-x. '.i.

10.)

granulosus, 289. d'l. XXII, ll^s i.-.n,

I..)

Meeki, 290. (I'l. XXII, n;,'r4. ICii, li.) ,

ornatus, 286, -Jhh. d'l. XXIII, ll^'s.

Ha-p.) striatus, 287, -iM. d'l. XXII, ngs.

till p.)

VIII'. t/rniiutnsiis, 2i^0.

MiiilrcporiU' in ('yatlinrriiiida :i.'i, 114, Ifi-J. Mariacrinus, •.'HI, 281, •.".»•-', .MC.

aureatus, 285.

Cirleyi, 282. (I'l. XXI, ll;;9, 20-0,)

/Itirrisi, -jxi, ,')17.

i/niiiiil<isiis, 282.

iii'irriijietiiliis, 2f>'2.

niihili'ssi'tniis, 2',li''),

ohcnniciis, .'i02.

pachydaclijhut, 29G.

(il2, I'd.-.. ('.17, 730.

rtelatui, 7;io,

dactylui, •-'(;:'.

~ - ilepreiiui, IM, 12ii, 7;il. d'l. III. il;,'.

2;i.)

pramaturui, 734. d'l. I. XXII, 11^14,

llii, ll.)

radiatm, 1Ih. d'l, VIII, lltf, I.'..)

itr.atm, 733. d'l. I. XXII, IIkh. 17, 1.x.)

tenneaseensii, 731, 7;i:i. (I'l. IAX\',

IIl,'H. H'.ll, I,,)

tentaculatui, 733. d'l. I. XXV, iln-<,

liPii, ll.) Mariupites, 12, 11, 17, ij.l, ll.'i. Mcgiitocrinui, HI. mi, U'li, 122, ;ic,2, .'iil.'i,

.•.l!i, 833, :<:<\. abnormia, ."d.'i, 546. d'l. XI. IX, ll^s.

Ill IM hnii'rurnis, .')l(.'l.

oonoavm, 543. d'l. XLVIII. II^h. .'m-c.)

depresius, 84" .Ml. (I'l. Xl.IX, IIh;». 2-

l,l.) Evanii, ;V.», ii;i, .■,.!2, 833. d'l. XI.VII,

ll-i. Iii-,-.c.)

var. craaaus, 836.

Farnaworthi, 639. (I'l. XI.VIII, ll-i.

Ill, ll.)

iiifi'li'j', .'"i2il, ,"i2."i.

Knii/i/)i\ .'i.ilt.

latm, 838. (I'l. XLVIII, IliiH. .In. li.)

Iiliiri'iitlilllils^ ^tiW.

multidecoratua, '112. (I'l. Xl.IX, llj,'. (1.)

— nt'n's, .*i2 1,

nobilis, ll'.i, 837. (I'l. XI.VII, (l-n. C-

.sh; I.I. 11;:. H.

nodosua, 841, .1 12. (I'l. X I.IX, llgs. fm, li.)

Oiitiirlo, .") ID.

j 'rfironlri's, .'lUlt, ."iaO.

piirriis, 5;!7.

- jillenliis, .111. fileinis, .MM, ."iM'i.

rugoaua, 642, ,>ll. (I'l. XI.VIII, llgn.

«a-c.)

\

\

I'

,"^.

V'

^J

Vi

830

GENERAL INDEX.

(PI. XLVIII,

XXII. figs. lOa-c.) (I'l. Xxil, fi-s. '.I,

(PI. xxni. 11^9.

Megistooi'inus spiuosulus, ^11 ligs. lii-2.)

IV/iilei, i>liO.

MelocrinidsB, 121, lOU, 170, 264. Jli'locrinites, -01, '261,

Meloorinus. 70. 7.s, 80, U.-i, 201, 282, 292.

eequalis, 301.

amplioru, .')87.

bainbridgensis, 297. (PI. XXII, flgs

4.1-c; XXIV, lit?. T).) — ^— /irei'iti(ic(i//us^ 21' 1. Calvini,"300. (PI. XXII, fig. 0.)

C/adei, 2117.

. gracilis, 298. (PI. XXII, (Ig. 5.)

bieroglyphicus, 21)3.

Uvis (Goh//.), 301.

Ittris (Iioemer), 302.

nobilissimus, 2lij. (PI. XXIII, figB. 1

2. 3.)

iiodosiis, 2ltl.

obconiuus. 302. P

oblongus, 300, 302.

I-'.)

~ ohjiiirtunnUtUs* 201.

pachydactylus, 296,

•1. .•) ; XXIV, figs. la. Ii.)

parvus, 303. (PI. XXII, fig. 8.)

/iiiiicidacli/his, 2110.

I'latteni. 21(1.

RoBmeri, 301. (PI. XXII, figs. Ua, b.)

sculptiis^ 21*1.

Tiffanyi, 299. (PI. XXII, flgs. Ua, b.)

Verneiull (//ull), ■>'.<[.

Venieuili ((Khlerl), 21)1.

Merocrinus, 08, 71, 127. Mespilocrinus, 11, 77. Metacrinus, l!», O.'i, 07. 70.

angulatus, O.'i. (PI. VI, fig. 9.)

Millericrinus, 30, .53, 00, 05, 01).

Carabofi. (PI. VI, fig. .5.)

icauuensis. PI. VI, fig. 3.)

Milleri. PI VI. figs, la, b.)

miinsterensis. (PI. VI, fig. C.)

Orbignyi, 01. (PI. VI, figs, la, b.)

polydactylus, 01. (Pl. VI. figs. 2a. b.)

Mollifications, palicoiitological, CI, 1)8.

Monocyclic, 33.

Moiiocjclic Criiioids. .'il, 00, 105.

derivation of, 07.

Muiwri/clira, 53. 157. Morpbological part, 38.

Moiitb, 21, 35, no.

anil Anns, 21.

iliscoveiy of in TaxocrinuB, 93.

Hycoorinus, 112. Mi/ehdticti/liii, 779. Myrtillocrinus, 1 II, 1,58. 172.

americanus. (PI. 111. lig. 13.)

.Myzostonia c^'sts, •' 1, 502. Ifanocrinus, 159. Xcie Kiicrinite, 017. Neornimulen, 03. 1 It, 118. Nodal joints, 33, 39. Ohiocrinus, 41, 71, 158. O/liierlniis, 236.

fuelltis, 215.

vbovaliis, 211.

reliculdtim, 211.

Sjiiiiigeriis, 217.

leniiirndialKS, 210.

tiibercidosiis, 213.

— — tiiberosus, 239.

tt/jiiis, 212.

Onoocrinus, 132, 100. 102. Onycb<^ster attacbed to ("rinoids, 500. Onychocrinus, 4;i. 77, 138, (I>1. VI. fig. 17.)

infrabfts.als coak-sced witli top stem joint.

(PI. VI. fig. U.)

diversns, 123.

Ulrichi, 123. (PI. VI, flg. 20.)

Orals, 20, 30, 30, 88, 155. (PI. Ill, figs. 2-25.^

of Antedon larva, 89, 99.

of Cyathocrinug, 05.

of Canierata, 80.

of Haplocrinus, 01.

of Larviformia, 80, 92, 98.

of Taxocrinus, 03.

Orientation, 37, 57. 153, 301.

of tlie axial canals. 00, 64.

of the basals, 50, 153.

of tlio cirri. 13. 00.

of tbe radii, 37.

of tbe stem, 45, CO, 08. (PI. VI, figs.

1-12. 18.) Ornigrannbis gronp, 701. Ornrenind, 90. Oropbocrinus, 20. Ottawacriniis, 08. Ontcr face, 158. Ovarian tnbc. 30. Paltencrinoideii. 25, 144. 148.

-v«

''^

V

GENKRAL INDEX.

831

PalivoEoIo Crinoiils, lOfi.

I'lilmus (Paliimiiii), 1"), 31, 71, 73.

ParabiisuUa, i);\.

Parisocrinus, i:., 77, V.Vi, i.v.i, ifii. l'!irasitic gi'owtlis. (I'l. IV, fv^i. 18-20.) Patelliocrinus, 7lt, 121, 2U,j, yu7.

rliiasludacli/liis, 2G.5.

iltipUcntHS, 2f'i,').

fiilmiiuiliis, 2fi.5.

p nnutiUus, 2)!.5.

Pelinrtio:on, 27, 111.

Pelfis, 13.

Pentacrinncea, 30

Peiitaciinidii-, 11, .'iO, O,-), 117, 1.52.

Pentacrinus, 13, 3.S, i:., .ill, GO, 05, 69, 81, Ml, 152.

asterias, 05. (PI. VI, fig. 8.)

caput-medussB, 11, il, 28.

europseus, 11.

■ naresianus, 5 1 .

— - Wyville-Thomsoni, 49.

Pi'iitagonal base, 1(15.

Pvntamera, 31.

Poiitameroua symmctrj', 1 17, 1G5.

Pentaphyllum, 115.

Pentremites, it.

Porieolioci-iiiitos, IG, SG, .^G2. 3G';, 519.

Periechocrinus, 4G, 3G2, 3G5, 519, 520, 551.

ampins, 530.

Chiisli/i, 522.

Howardi, 529,

infelix, 525. (PI. L, figs. 2a-(l.)

mircouanus, 523. (I'l. L, ligs. in, b;

I.I. lig. 5.)

moniliformis, 520.

neois, 521 (1*1. I„ figa. la, b.)

ornatus, 527. (PI. L, figs. 3a, b; LI,

fig. 7.)

PWiformis, 52G

■ speciosus, 521 528. (PI. L, figa. Ga, b.)

Phialocrinns, 80.

Pliilllpsocriniis, 2'.ll.

Pli^'logoiictie history reprcseutcd in iuiliviilual

growth, 101, IGG. Physetoorinug, 85, 109, 122, 548, 550, 554,

593, G37.

iiMiL'r iloor of, 120.

asper, 596. (PI. LXIII, figs. 7a, b.)

Copei, 598, (PI. LXIII, fig. 5.)

dilatatus, 595. (PI. LXIV, figs. 9, 10.)

lobatus, 699. (PI. LXIII, figs. «a. b. )

ornatus, 697. (I'l. IV, fig. 3; LXIII,

figs. 1-4.)

siihfciilri'cosiis, 593.

ventricosus, 593. (PI. IV, fig. 2 ; LXIII,

fig. G; LXIV, figs. l-8b.) Piiimistrlhi, ] G. Piiinata, 152, 1.55, 1G9. Pinnules, 34, 73, 80, 85, 155, 100. Pisocrinus, 57, 70, 72, 130, 157, 172, 205.

(PI. Xir, fig. 10.)

— pilula, 90. Pl.iiiiia group, C08.

Plntyccr.is attached to Crinoids, 240, 560, 793, 800.

PlatycrinidsB, 17, 83, 100, 124, 103, IGO,

170. 642, 713, 803.

distriluition of, 643.

Plati/n-inilrs, 047.

Plat'yorinus, 13, 41, 40, 48, 57, 77, 79,83, 91,

94. 90. 102, 111, 113, 135, 149, 156, IG.i,

042, 644, 647, 719, 730, 738, 744, 750, 753.

(PI. IV, fig. C).

(ibseiitiriis, 050.

acclivns, 663.

BBqualis, 674. (PI. LXXI, figs. 4a-5.)

sequiternus, 658, 059. (PI. LXXI, fi".

12.)

— (Pternalls, 050, 083. Agassizi, 050, 669. (PI. LXIX, fig. 4.)

tennesseensis, 528. (PI. L, fig. 4.) ' al„hamei,s!s, 050, 678, oso.

tenuidisous, 531. (PI. XLVL fig. 4;' allophylns, 685. (PI. LXXI, fig. 17.)

^^f' "S' «•) I amabilis, 050.

nrniformis, 526. (PI. L. figs. 5a, b.) amerioanus, 686, (PI. LXXV fi<rs 10-

— Whitei, 530, 020. (PI. XLVI, figs. 1-3 ; 13c.)

'■f-"-"^-"' '<'•> onnoms, Gr,0.

■ Whil!i,.Mi, 522, 520. (PI. LI, figs. 1-1.) nltlttnrmtm, 050.

Periglyptocrinus, 80, 198, 204. 277. mper (Go!,//.), 690.

BiUingsi, 277. (PI, XXI, figs, la, b.) ! asper (AI. and W.), 690. (PI. LXVIII

prisons, 278, (PI. XXI, fig. 2.) i figs. 9a, b.)

Perisomio plates, 36, 118. iatlola, 050, 074.

i

,' 'I

i 1

\

■ !l

i,^

f

8J2

GEXKUAL IXDKX.

-!^

Platycrinus Bluin', (I'lU.

hl.t.imjiMvnsis, (l.'id, (Ki.'^.

bonoensis, Osj, 683. (I'l. I.XIX. Og. C.>

boonvillensis, 681. (I'l. LWII, ligs. j iusolens, 659. (I'l. l.XXI, lig. 15.)

f<.l-;i.) iiiuniiiliis, iiol, G.'>3.

brevinodus, 688, 01)0. (I'l. LXX. lign. lievis, ClU.

PlatycrinuB HunUvillee, S 1, 678. (I'l. LXXIII,

liga. G-lL'.) incomptus, (ilis, 664. (I'l. LXXl, figs.

1,1',;!.)

•-'. j, (Ja, I).) Britsi. 659. (I'l. I-XXI. lig. 10.)

llrimdhcivU, i\M, C.si).

burlingtonensis, lO.i, (M'.i, 653, (V.T, tiDl,

iM. (I'l. LXIX, ligs. ya-i.j

ciiitKciis, G.')0, Gh3,

cali/i'iilus, G.')0.

oanaliculatus, 689. (I'l. LXXV, ligs.

7a. 1).)

niirhesiiim, G.'jO, G.'iG.

oivus, 715. (PI. LXVII, ligs. Ma, b.)

,-li/N's, (i.'il, (!;•.").

cliDiitciiueiisi's, C.'iO.

• Collelli, G.VJ.

concinnits, G.IO.

contritus. 667. (I'l. LXXI, fig. «.)

comtf/afits. G."(l. 71'V

corbuliformia, 657. (I'l. LXXI, ligs.

11 a. I).) rnrn/n'//riisis^ C.'tl, ('.Vs.

Divisi, 681 (I'l. LXX. lig. 1 1.)

discoideus (O. ami .Sli.), lo:>. 713, TIG.

(I'l. in. lig. 17; I.XVr, ngs. KJa-c.)

Himiilfiis {Hill, ISoSt. 71:i, Ti'l.

clwriircus, G.")0.

ilfi/iois, GGll.

eminulus, 712. (I'l. LXVIH. (igs.

i:!a-o.)

. eriensis, Gt7. 676.

excavatus, Gl'.i, 718. (I'l. LXVI, fig.

1.)

cxsertiis, fi.'il, Ci.'i^, G.").'>.

geometrious, 697. (PI. LXVII. lii;, 10;

LXVII I. lig. 8.)

Gi-oiyei, 6.')1, fi77.

- glyptus, 693, 7-20. (PI. LXVII. figs. 1-0.)

Oorbyi. 716. (PI. LXVITI. fig. ir,.)

graphious, 672. (PI. LXXI. fig. 7.)

-Halli, 10:5. 662, GGl. (PI. LXXII. fig.s.

Ga-71).) Iliiidrnl. G.'iO.

hemisphericus, 703, 700. 7113. (PI. LXVI.

figs. la-U.)

Uiitttt^, G.')l, COO, Go.").

Lciii, 71G.

lodensis, 666. (PI. LXXI. lig. G.)

muryimilKs, (!,"iO.

iiKiiiiociisis, CJl, G7M.

tinillihracliialus, C.'il, 713.

niotensis, 682. (PI. LXXI, fig. n.)

m:duhnu-hi,itus {Hull. JS61), G.M, 70H.

iwiliiliriic/iiiilus {//(ill. ISoSt. 0.-)l, C.'ui. 0,1,').

nodostriatus, G.^.^, 698. (PI. LXVI, figs.

iK\. h: LXX. ligs. 3-lc.)

ii'ii/usiis, C.")0.

iHiiliilosiis, G.'il, 701.

iiiicli'i/oniiis. G.')l, G.')3, 055.

oeciilenlalis, 72H,

».//.( {//nil. not (le A'oH.). CJl.

oUicula, 667.

ornigranulus, 701. (PI. LXVI, fig. 8;

LXVIII, figs. Ilia iL'l); LXXII. fig. 10.) (hrnii. G.")l, 710.

parvinodus, 696, 701. (PI. LXVIII, figs.

lia. li.)

/Kirniliis. 773.

/larnts. G.'tl. 73.'), 737.

peculiaris, 70C. (PI. LXVIII, ligs. 7a,

1); LXXI. fig. IG )

jiiiiiri'lliis. G.'il. G7S.

pi'ittiiijonus. G.'iO.

prrasprr. 7(1.S,

pliiiinhnsiilis, O.'il. OGl.

pileiformis, 656, G03. (PI. LXIX. fig.

.-|; LXX. figs. 13.a-b.)

pisum, 660. (PI. LXXI. figs. 13a-b.)

phniiis l/hlh. 0.-,l, GO-.'. OO.s.

planus (O. and Sli.), 668, 070. (PI.

LXIX. fig.s. 2a-(L)

pleiiiis. G.'il, G7>*.

plffirnrinu'ifus. O.'tl. 721.

pliimosjis. G.M , 73.1.

pocilliformis, 706. (PI. LXVIII, figs.

■2n. h.)

prirmntiiriis. G.'il. 731.

prcrnunfins. G.'il, 720.

piiillcnaiiiis, G.'il. 078.

I'

m

^'

■> 1'

>, "

.4^^

4r- t:

GENERAL INDEX.

833

Platyorinus Prattoni, GG8, 671. (PI. LXX, ngB. u, 12.)

pukhelltis, Col, 713.

pumUus, GuO.

piinctulirncliialiii, 7.")0,

qainqnenodui, 661.

1 la-c.)

ramuhstis, fi.'il, 73.'), 7.37.

regalh, 710, 712. (PI, LXXII, ngs. 1, 2.)

retiiin'iis, 735.

rif/ifielilcniis, C.')l, 672.

rutnndm, n.")l, GDI,

Saffordi, 694. (PI. LXVn, figs. 1-.3.)

Sampioni, 673. (I'l. LXX. Ilg. 10.)

SniTC, 84, 677, CH2. (I'l. LXIX, fig. 7 ;

LXX, tig. 1.) scobina, 695, G97. (PI. LXVIII, figs.

1 la, b.) soulptM, 691, 693, GO.'). (PI. LXVIH,

fig. fl ; LXXV, figs. 8, 9.)

s/iumardianus, G.')l, 713.

spinifer, 708. (PI. LXVL Hg. 7.)

var. elongatns, 709. (PI. LXVII,

fig. 7.)

striobrachialus, G.M, 713.

subspinoins, 717. (PI. LXVI, figs. Oa, b.)

subspinulosns, 684, Cs,), 704. (PI. LXVL

figs. 2a, b; LXX, fig. 9.)

stilcaliis, G.')l, 718.

symmetricus, 103, 118, 655. (PI. Ill,

fig. 10; LXIX, figs, la-c.)

leiincsseensis, Gol, 731.

lenlaculuttis, G.'il, 733.

tenuibraohiatns, 687, C99. (PI. LXX,

figs. 7, 8.) truncatnlns, G 17, 675. (PI. LXVII, figs.

11a, b; LXXI, figs. 18a, b.)

Iruncalus, G.')l, GHG.

tiiberostis, G.')l, 720, 728.

verrucosus, 705, 70G, 709. (PI. LXVI,

figs. 3a, b; LXVIII, figs. Ia-<1.)

rexdAiVi'j, G;"iO.

Wortheni, 702. (PI. LXVII, fig. 9.)

Yandelli, 103, 706, 708. (PI. LXVL

figs. Ga-c; LXVIII, figs. 3a-c.) var. perasper, 708. (PI. LXVIII,

figs, la, b.)

iiiulcBci'ibcd species from Englr.nd, 611.

Pleurocrimis, G17, G49, Plicatocrinidce, 30. Polt/crinides, 18.

Poli/mera, 31.

Polypeltes, 30.'i.

Pores ill I'oteriociiiiidiE, 114, IIG. (PI. VII,

figs. 4, 7, 8, II.) Foroorinui, G7, 140. (PI. LXXI, figs. Position for flgiiiliig, 37. Postpalniurs, 34, 73, 76. PoteriocrinidSB, ,'>8, 8", llG, ^^>'^, IGl. Foteriocrinus, 13, 87, 127, 159.

missourienais, 78.

Pradoerimii, 519, 521.

ampins, 530.

Primary liracliials, 34.

Priiiiaiy i)hites, 38.

Pioxiinal, 37.

Proximal phites (proximals), 90, 95.

Proximal ring of base, 54.

P.sendomonooycliea, 59.

Pterotoorinus, 77, 79, 83, 112, 741, 781, 791.

(PI. LXXIX, fig. 1(1.)

acutns, 799. (PI. LXXIX figs. 3a- g.)

var. bifarcatus, 801. (PI. LXXIX,

figs. 9a, b.) oapitalis, 793, 794, 799. (PI. LXXIX,

figs. Ga, b.) — - chesterensis, 802. (PI. LXXIX, figs.

5a, b.)

cornigeruf, 783.

coronarius, 795. (PI. LXXIX, figs.

7a, b.)

crassus, 801. (PI. LXXIX, fig. 8.)

depressiis, 796. (I'l. LXXIX, figs. 2a-c.)

pyramidalis, 798. (PI. LXXIX, figs. 4a,

b.)

riigosiis, 799, 801.

sexlohalus, 7m.

■ sjuitiilatiis, 799.

Ptyohocrinus, 188, 197.

angularis, 199.

-parvus, 177, 199. (PL XVIH, figs, la,

b, 2.)

. priscus, 198.

splendens, 198. (PI. XVIII, figs. 3a, b.)

Pi/cnocriniJees, 1 7. Pycnocrimis, 175, 268, 273.

S/iaffi-n; 272.

Pi/xldocrhitis, 519, 521. Qiiinqiielocular or Dorsal organ, 45. Radials (Radialia), 15, 33, 68.

compound, 71, 158.

limits of, C7.

105

4l'4.T>,;;

i

4-

834

GENERAL INDEX.

i I

^]

Riuliiil tlome plates, 30, 103, 10». Rmlial facets, 87, Itil. Rmlianal, 35, 72, 126. Reeuperativo power, 135. Rogalia group, 710. Uospiratory pores, 3."), 122, 238, 311, ReteoorinideB, lOC, 113, 117, 173, 8U3. Reteoorlnus, G7, 113, 119, 17J, 176.

. Bierl, 177, 18,j.

cognattts, 180.

flmbriatus, 177, 179. (PI. IX, fig. I.)

. — —gracilis, 177, 1 !•'.'.

magnifloug, 181. (PI. IX, fig. 2.)

Onealli, 179. (PI. IX, ilgs. la-f.)

Pallersoni, 177.

Richardsoni, 177, 271.

stellaris, 77, 177, 178. (PI. IX, figs.

3a-c.) Rhaphanocrinus, 21.'>, 2.'i8.

sculptus, 260. (in. XI, fig. 3.)

subnodosus, 250. (PI. XI, lig. 2.)

Wachsmuthi, 2,')l).

Hhizocrinus, 28, 10, 40, 58, G2, 91, 1 12.

lofotensis, 03, 70.

Rawsoni, 51. 03, 70. (PI. VI, figs. 7ii.

h.) RhodocrinidsB, IOC. 121, 105, 170, 215, 2.38. Rhodocrinus, 13. tl, 11, GO, 83, 215, 218,

233, 238, 249, 201.

iisppt'nfiis, 251.

Barrisi, 230. (PI. XII, figs. 3, 4a-d,

5:1, ll.)

var. (lircrgens, 230.

var. striatus, 231. (PI. XII, fig. G.)

Benedicti, 224.

coxanus, 222. (PI. XIII, figs. 6, 7.)

ccelaitis, 228.

gonidudes, 80, 219.

i/racilis, 220.

///(//)•, 190, 219.

-Kirbyi, 44, 226, 228, 337. (PI. XII,

n.,'s. la-il.)

meliss'i, 219, 203.

microlmsilis, 192. 219, 250.

— -ninus, 41, 228. (PI. XI, figs. 7a, b;

XII, figs. 2a, 1).)

nDdulosus, 225. (PI. XIII, fig. 8.)

parvus, 229.

/I't'i/daHi/Ins, 222.

pgnformis. 192, 219, 255.

quinqtu'luhiis, 192.

Rhodocrinus rectus, 220.

sculptus, 228.

spinosus, 220.

stMaris, 219, 236.

trunoatus, 231. (PI. XIII, figs. 2a-f )

tuberculatus, 232. (_P1. Xlll, figs. 3, i j

varsoviensis, 220.

verus, 219.

vcspcrulis, 219, 251.

Wachsmuthi, 222. (PI. XIII, figs. 5a-d ;

XV, fig. 7.)

watersianus, 221, 229. (PI. XII, fig. 9.)

Whitei, 223. (PI, III, fig. 24; XIII.

Ilgs. la-c; XV, figs. Oa, b.)

var. Imrliiiglunensis, 223.

Wortheni, 220. (PI. XI, fig. G; XIl,

figs. 7a-c.) var. urceolatus, 221. (PI. XII, figs.

8n, b.) Ripidocrinus, 70, 8G, 215, 202, Higlit aiul left, 37. Hoiit, 32, 39. Rosette, 54, 141. Siircorrinus, 519, 522.

lieiiciUcli, 527.

C/iristi/i, 522, 525.

Kgani, 525.

Gorhiji, 521.

— — IfoH-ardi, 529.

iiifidix, 525.

marroniniiis, 523.

vcris, 524.

oritdtns, Ty'21,

piriformis, 526.

semiradialiis, 289.

speciosiis, 521. 528.

teniiesseeiisis, 528.

uriiifi>rmis, 520.

W/iilfrldi, 522.

M'/u'lci, 530.

Sagenocrinus expansuB, 219.

Sar-TB group, 677.

Saumi)l:itte!ien, sec covering plates, 30.

Scaphiocrinus, 44, 159.

elegans, 138. (PI. VII, figs, la, b.)

unicus, 138. (PI. VII, fig. 6.)

Swallovi, 138. (PI. VII, fig. 8.)

Scnpultr, 13. Schizocrinns, 77. Sculptus group, 091. Scyphocrinus, 204.

..iv

\

GENEUAL INDEX.

83o

J»

Soytalocrinna, 100.

validus, VM. (Vl VII, 2a, b, 3.)

iiov, sp. (in. VI 1, flj;. 7.)

robuatus, 50(5.

Seeomliiry Ijrucliiiils, 31.

Siilo pieces; see -Vdiimlnilncr.al pliitcB, 100.

Siphonoorinus, l-'O, ) -.', Lsm, 209.

armosus, 1U7, U'i, 811. (I'l. XIX, llgs.

3a-c.) nobilis, 212. (PI. XIX, ligs. la. b,

2a-c.)

pentagonus, 213 (PI. XIX, figs, -la, b.)

Species, recogiiiliuu of, 10.j.

characters of, l.'iCi.

tleacriptioiis of, (l.")2.

Si)iiies, movable, 71H, 700.

Splucrocrinus co/icants, 182.

Spliieronites, 1.').

Spliaroidocrinacea, 29.

SiiharoulocrinhliP = sijn. of Cumeriita, 25.

S/iyridwcrintis, SCtj.

Steganocrinus, 7C, 8.'), 101, 110, 2i)3, o.")0,

Ool, 578, C39, 720. araneolus, 1(JU, 581, 723. (PI. LXI,

flg9. 2a, b.)

Henedicti, 507.

eoncinnus, 582. (PI. LXI, figs. 5a, b.)

globosus, 585. (PI. LXI, fig. G.)

pentagonus, 110, 112, 579, 723. (PI.

LXI, figs. 3!i-lb.) soulptus, 78, 8G, ICO, 293, 583. (PI.

LXI, figs, la-f.) Stelidioorinug, 79, 2G1, 279.

argutus, 280. (PI. XXIV, fig C.)

capitulum, 280.

lavis, 280.

ovalis, 280.

Stem, 32, 38, 155.

figures of; PI. I and II ; VI, figs. 11,12.

growth of, 39.

divided loiigitiuliiiallj', 41.

res|)iratory fiinctioii of, 47.

semi-free, 49, 51.

with coalesced iiifrabasals. (PI. VI,

fig- 11.)

of Barycriniis, 45.

of Cupressocrinus, 45.

of Uegistocrinus, 4G.

of Flatycrinns, 42.

of BhizocrlnuB, G3.

of Strotocrinus, G39.

Stem joints, 32, 41.

tup joint (centrodorsal), 33, 59, 01,

G4.

_ top joint (youngest joint). 59. GIl.GO.

Stemmatocrinus, 59, 8(i, 127, 133, IGO, 1G2. StephanoorinuB, IIG. — angulatus. (PI. VII. figs. 12, 13.) Stereoorinus, 77, 121. 2(;5, 324.

Barrisi, 326. (Pi. XXV, figs. 9a. b.)

triangulatus, 325, 32G. (PI. XXV, figs.

8a, b.)

var. lirdtiis, 320.

Stoniatijcii'iwi'den, 25, 1 IH, Storthingocrinus, 57, G17.

— tiapcr, 090. Strotocrinus, 70, 85,110, 551 , 554 , G2G, 637, 038.

aaper^ 59G.

(isperriiiiiis, 575.

aijilu/is, (i28.

bluonijicldensis, 038.

clifosits, G30.

dihlalus, 595.

eclijpus, Oil.

erodiis, 030.

glyptus, 640. (PI. LX, figs, la-c ; LXV,

figs. 2a, b.)

insciilpliis, 030.

li'mtiis, G33.

pcnnnhrosus^ 038, 010.

regalis, 39, 638, G40. (PI. IV, fig. 1 ;

LXV, figs, la-d.)

rudis, 030.

siibumlirosm, 033.

teniiiriiduitiis, 034,

vmfirosiis, 028.

Sl,/lid>i, 17.

Sith-bfts(ds^ 00.

Siiliradials (soiis-rndndis). 17, 30.

Subspinnlosna group, 683.

Siibtegminal, 35.

Sul)tcntacnlar canal. 30. 100.

Superimposed plates, 119, 121.

Super-radi.ils, 33.

Supplementary plates, 31, 38, 105, 154.

Sutnrc, 37.

Symmetry, bilateral. 134, 148.

irregular, 14G.

pcnt!\merous, 134, 140, 148, 105.

Symbathocrinns, 57, 87, 91, 130, 157, 172. Wachsmuthi. (PI. IH, fig. 25; VIII.

figs. 8, 9.)

«lii->

»

\

836

GEXEIUL INDEX.

15

Symbathoorinus Swallovi. (PI. VIII, fig. 7.)

Syzygy, a I, hi.

Talaroorinui, 7li, 711. 781, 7Hi, 71t;l.

sp.C.') (IM. LXXVIII, ligs. I'll, l>)

oornigerui, 783, 7HJ. (I'l. LXXVIII,

figs. (!a-71). ) deoornw, 788. (I'l. Ill, llg. Ill ; LXXVIII,

figs. Jill-C.) — cleyrnis, iHCi,

ovatus, 787. (PI. LXXVIII. figs, ia, b.)

sexlobatns, 784. (PI. LXXVIII, llgs.

In-c.)

simplex. 790. (PI. LXXVIII, figs. Sn, b.)

siibglobosiis, 789. (PI. LXXIX, figs.

In, b.)

symmetrioui, 786. (PI. LXXVIII, figs.

4a-5.) Tanaocrinns, f,7. 17.3, 185.

typns, 186. (PI. IX, figs. 7a-c.)

Taxoorinus, 17, -.'h, .i;5, 70, 9;<, Uh, 13S, 1 lit, (PI. VI, fig. IC.)

intermediui, 118. (PI. Ill, fig. 11;

VIII, figs. 5a. b.)

Thiemei, 1.!:).

Technocrinus, I'lM, 304.

Andrewsi, ;!()«. (PI. XXIV, fig. 3.)

srti/pliis, nO.">.

spinulosus, 305. (PI. XXII, fig. 3.)

striiitiis, 'Mo.

Tognien, 33.

imior fioor of, lOG. (PI. V. figs. 13-17.")

of Actinocrinug and Batocrinas, lOSi,

121.

of Olyptocrinus, I'-l, 113, 120.

of Platycrinus, 21, 111.

Ti'gininal, 3.5.

Teleiocrinus, «.•,, 102. 121, 1 l;i, r>r,o, o.Vl, ")7C, 626, G37. (PI. IV, fig. 1.)

adolescens, 635, (VM). (PI. LIX, fig. I.)

{Tf/i/ojis, 02H.

althea, 638. (PI. LX, fig. 4; LXIII.

fig. !l.)

clifisiis, 030.

emdiis, ()30.

iiisciil/t/us, (130.

liratus, 633. (PI. LX, fig. 3.)

rndis, 630. (PI. LIX. figs. 1-3.)

tenuiradiatus, 634. ( PI. LI X, llgs. '),r,)

umbrosus, .50, 628, G31. (PI. LIX, fig.

7; LX, figs. 2a-<l.) Tcrmiiial plates of stem, 48, 51.

Ti'raiinology, 32, 76. Temelldla, 15, 23. Tvtramerii, 31. Thaumatoorinn*, 72, 117, 139.

renovatns. (PI. Ill, fig. 9.)

Thylaoocrinua, 215, 248.

Clarkei, 248. (PI. XIII, figs. 11a, b.)

Vannioti, 2 18.

Thy«anoorinid», 72, 121, 1C5, 170, 188, 217. Thysanoorinui, 188, 190.

aciilealus, 192.

brachiatM, 105. (PI. XVIII, fig. 7.)

cniirili'ciilittiit, 192.

Halli, 196. (PI. XIII, figs. 9a, b.)

imiiialurus, 192, 200.

inornatui, liU, 193. (PI. XVIII, figs.

fia-d ; XIX, fig. 5.) liliifonniB, 191, 192. (PI. XVIII, fig.

i-) ocoidentalii, 194. (PI. XVIII, figs.

5a-c.)

var. increbcscens, 195.

ini'cnibtisilis, 192, 256,

pyifi'miis, 192, 255.

Tiaracrinus, 146. Transition forms, 146, TieitKitneriiiiis, 231.

Jiscellits, 245.

papilldtus, 242.

retiiiilatiis, 214.

■ — — rohuslus, 239.

sphiiijeriis, 247.

tuberciitosiis, 243.

ti//>iis, 2 1 2.

Tn'dcriiiiis, 57. Tribrachiocrinus, 148, 158. Trimera, 31. Trochncrinitea, 519, 521,

hvvis, 521.

Trocliitos, 11. Triincatiiliis gronp, 675. TnjhUnrrin us, 216. Tiirblnncrhiites, 292, 294. Uintacrinns, 63, 145. TTlocrinns. i:!:). I'niserial, 34, 78. Uperocriniis, .'16(), 434.

pistilliforinis, 437.

pi/rlformi's, 434, 437.

fppor face. 37.

" L'p " and " down," 37.

^

^

GENERAL INDEX.

837

Vault, 20, 105, 121, 1 18.

is ft niodifled disk, 124, Ml).

Ventral disk, 3n, 35, 05, 118, 121, 150, 154.

(PI. Ill, nga. 1-25 J IV, llgB. 1-5.) Veiitml sac (lubo), ;J5, 114, 12;', 157, ICl.

(IM. VII, llgn. 1-12.)

Water pores, 12;1. Xenoorinns, IJ7, 17:1, 17.'i, 188.

Baeri, 183. (IM. IX, (Igs. Sn-d.)

penioillus, 183. (I'l. IX, figs, lia, b.)

Zeaorinui, 52. Zophoorinut, 140.

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41!

I'UBLICATIONS

or THR

MUSEDM OF COMPARATIVE ZOOLOGY

AT IIARVAKD COIiLEQE.

There have been publiBhed of thfl Bullbtins Vols. 1. to XXIX.; of the Memoirh, Vols. I. to XXIl.

Vols. XXVJII. aiid XXX. cf the Bullktin, and Vole. XIX. aud XXIII. of the Mimoirs, ant now in courae of publication.

A priee lilt of the publieationi of the Mmeum will be unt on application to the Director of the Muteum of Comparative ZoiAoyy, Cambridge, Mate.

ALEXANDKR A0AS8IZ, Direetor.

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