RHODOCRINIDiE. 249 



ment stelliform, somewhat concave, tlie margin surrounded by concentric stri^ 

 as in Jurassic PentacrinidaB. Basals large, slightly curving upward. Radials 

 as wide as high, of the same size as the costals. Distichals 2x2, a little 

 shorter than the radials. The four lower palmars form part of the calyx, 

 the upper are free ; the fixed plates considerably highest, but decreasing in 

 height upwards; the three proximal arm plates subquadrangular, the suc- 

 ceeding ones gradually turning from cuneate into biserial, meeting laterally 

 by a zigzag suture. Arms four to each ray, simple ^throughout, rather strong 

 at the bases ; their length unknown. Interbrachials : 1, 2, 3, 2, etc., some- 

 what smaller than the adjoining brachials. Anal interradius wider, with 

 three plates in the second, and four in the third row. Interdistichals in 

 about six ranges, arranged in pairs from the first plate up. Interpalmars 

 three to four, arranged longitudinally in single file. Ventral disk and 

 anal opening unknown. Column pentangular with re-entering angles near 

 the calyx ; the joints of nearly equal width ; the salient angles of the nodal 

 ones bearing a small tubercle. 



Horizon and Locality. — Hamilton group ; Canandaigua Lake, N. Y. 



Tyjpc in the New York State Cabinet of Natural History at Albany. 



Remarks. — The species is described from a somewhat crushed specimen, 

 formerly in the collection of Prof. John M. Clarke of Albany, N. Y., in whose 

 honor the specific name is given. 



DIABOLOCRINUS W. and Sp. (nov. gen.). 



(Aia;8oA.os, tlie devil ; Kpivov, a lily). 



Syn. Ehodocrinus (in part) — White, 1880; Proceed. National Museum, Yol. II., p. 259. 



Syn. Lyriocrinus (in part) — S. A. Millee, 1882 ; Journ. Cincin. Soc. Nat. Hist., Vol. V., p. 117. 



Syn. ArcJi(Eocrinus (in part) — W. and Sp., 1885 ; Proceed. Acad. Nat. Sci. Pliila., p. 320. 



Syn. Archcsocrinus (in part) — W. and Sp., 1885 ; Eevision Palseocr., Part III., p. 98. 



Syn. Archaocrims (in part) — S. A. Miller, 1889 ; N. A. Geol. and Palseont., p. 225. 



Calyx depressed globular, with a wide and deep concavity at the bottom, 

 involving the infrabasals and large portions of the basals. Infrabasals five, 

 small, but projecting beyond the column. Basals large, elongate ; their 

 upper half directed horizontally or bending upwards ; the upper faces broadly 

 truncated. Radials not in lateral contact, being separated from each other 

 by one or more plates, which rest upon the basals. Costals two. Arms two 

 to the ray, free from the first or second distichals ; their structure unknown. 

 Arm openings very large, directed obliquely upward, and arranged in groups. 



32 



