730 THE CRINOIDEA CAMEEATA OF NORTH AMERICA. 



MARSUPIOCRINUS Phill. 



(Not Marsupicrimtes Blaintille = Marsiipites Mant., nor Marsapiocrimtes Hall = Li/riocrmus). 



1839. PuiLLiPS apud Murchison ; Silur. System, p. 672. 



1813. Austin ; Ann. and Mag. Nat. Hist., Vol. X., p. 109. 



1857. PiOTET ; Traiti5 de Paleont., Vol. IV., p. 332. 



1860. Ddjakdin aud Hnpfc; Hist, naturelle des Zoophytes, p. Ii9. 



1878. Angelin ; Icon. Crinoid. Suae., p. 2. 



1879. Zitiel; Handb. der Pateont., Vol. I., p. 365. 



1881. W. aud Sp. ; Revision, Part II., p. 62 (Proceed. Acad. Nat. Sci. PhiJa. p. 236). 

 1890. S. A. Millee; North Amer. Geol. and Palajont., p. 260. 



Syn. Plttti/crimis (in part) — -F. Roejieb, 1860; Silur. Fauna TVest. Teun., p. 35. 



Syn. Oupelleecrimis — Teoost; 1850, List Crin. Teun., p. 61; described by Shum. 1866; Cat. 

 Palseoz. Fossils (Trans. St. Louis Acad. Sci., Vol. II., p. 361). 



Closely related to Plati/crinus, but the lower brachials and the first plate 

 of the interradial series entering rather more into the dorsal cup ; the radial 

 facets, instead of being excavated, are nearly straight; the column circular 

 instead of elliptic ; and the axial canal very much larger and pentagonal. 



Basals arranged as in Plcdycrinus, and similarly anchylosed. Radials 

 large, hexagonal in outline ; the upper face suj)ports not only the costals 

 but also the distichals ; it is straight, or slightly indented for the reception of 

 each plate. Costals one, very small and trigonal. Distichals one when there 

 is another bifurcation above ; they are small, resting with their lower faces 

 upon the radials, with one of their lateral faces against a large interbrachial 

 plate, and at the opposite side against the adjoining distichal of the same 

 ray. Arms from two to four to the ray, rather stout and biserial; the 

 pinnules large. Ventral disk hemispheric ; the orals rather small, pushed 

 anteriorly, and quite asymmetrically arranged. The ambulacral jolates con- 

 sist of regular rows of covering pieces, which branch upon the disk, and are 

 separated from those of adjoining rays by rather large interambulacral plates, 

 and the branches from one another by one or two interaxillaries. Column 

 of uniform size throughout, and, so far as observed, without cirri, except 

 perhaps at the extreme end. The joints circular, each pair of nodal joints 

 enclosing an internodal ; the axial canal moderately large and jjentagonal. 



Disty^ibution. — The genus occurs in Europe as well as America, and is 

 restricted to the upper Silurian. 



Type of the genus : Mm^suplocrinus cmlatus Phill. 



Bemarks. — Among his list of the Crinoidea of Tennessee, Troost gives 

 under Cupellcecrinus the following species : CupieUmcrinus Buchi, C. conniffoiics, 



