1888.] NATURAL SCIENCES OF PHILADELPHIA. 383 



1854. Salter, apud Murchison, Siluria, (Ed. 2), p. 219 ; (Ed. 3), p. 

 247, figs. 4, 5, 6, 7. 



1855. McCoy, Brit. Pal. Foss., p. 54. 

 1873. Salter, Cat. Mus. Cambr., p. 1 23. 



1878. Angelin, Icon. Crin. Siiec, p. 26, PL 7, PI. 8, PI. 17, PL 25. 



1879. Zittel, Handb. d. Palaont., I., p. 356, fig. 244. 

 1882. De Loriol, Pal. de France, tome 11, Crin., p. 51. 



1886. Wachsmuth and Springer, Kev. Palceocr., Pt. III., p. 165. 

 1886. P. H. Carpenter, Ann. and Mag. Nat. Hist, for November, 



p. 397. 

 Syn. Cyathocrinus, 1821, J. S. Miller, Nat. Hist. Crin., p. 89, with 



plate; Antliocrinus, 1853, Joh. Miiller, Abli. Akad. Berlin, 



pp. 188-192, PL 8 ; 

 1855. Roemer, Lethrea. Geogn. (Ausg. Ill), p. 255. 

 1855. Quenstedt, Handb. d. Petref., IV, p. 943, PL 75. 

 1857. Pictet, Traite. de Paleont., IV, p. 312, PL 100. 

 1860. Bronn, Klassen. d. Thierreichs., (Actiuozoa), PL 27. 

 1862. Dujardin and Hupe, Hist. Nat. Zooph. Echinod., p. 117. 



Generic diagnosis. 



When the arms are closed the crinoid resembles an elongate bud 

 with folded leaves ; when these are spread, it is wheel shaped, with 

 five lanceolate areas between the bases of the rays. Calyx sub- 

 globose, flattened above. 



Underbasals 5, large, pentangular, of uniform size. Basals 5, very 

 large, extending three fourths the height of the calyx, all hexagonal 

 except the posterior one, which is higher and has the upper angle 

 truncated for the reception of a comparatively small, quadrangular 

 anal plate, which rests between the first radials. 



First radials much wider than high, their distal faces thickened, 

 either concave or straight, and occupied by small, shallow depres- 

 sions for the reception of the second and higher radials, which to the 

 third or fourth order rest partly upon this plate. The second radial 

 occupies a very small space at the middle of the first, where it ap- 

 pears as a small, trigonal bifurcating plate, sometimes scarcely visible 

 dorsally. From its dorsal or outer side to its ventral side, the plate 

 is very long and slender, bent upwards almost to a right angle, so as 

 to bring the face opposite to that exposed dorsally into a horizontal 

 position, and on a level with the vault. The secondary radials rest 

 against the sloping faces of the second primary, and upon the first ; 

 they are bifurcating plates, and as such support immediately the ter- 



