386 PROCEEDINGS OF THE ACADEMY OF [1888. 



Between the covering plates, and abutting against the four smaller 

 orals, are two or more interradials, the inner ones the larger. Be- 

 tween the radial-dome-plates, and against the large posterior oral, 

 are numerous small anal plates which embrace the anus, and of 

 which the outer ones face the anal plate of the dorsal cup. The anus 

 is excentric, and its form varies among species, being either extended 

 into a tube, or placed at the top of a small protuberance. The tube 

 apparently reached considerable length, and seems to have been 

 composed of several rows of transverse pieces longitudinally ar- 

 ranged, with a large octagonal cavity. 



Column very large ; terminating in numerous rootlets. Canal 

 large, round. 



Geological Position, etc. Upper Silurian of England and Sweden. 

 List of Species : — 

 1840. Crotalocrinus jndeher Hisinger, ( Cyathocrinus jyulcher), Leth. 

 Suec, Supp. II., p. 6, PI. XXXIX, figs. 5 a. b.-1878, Angelin, 

 Iconogr. Crin. Suec, p. 26, PI. VII, figs. 5—7 a, b ; PI. VIII, 

 figs. 1— 9a ; PI. XVII, figs. 1, la— d ; PI. XXV, figs. 8— 

 20.-1879, Zittel, Handb. d. Palaeont., Vol. I, p. 357, figs. 2, 

 4, 4 a — e. — 1886, W. and Sp., Revision Palseocr., Pt. Ill, p. 

 150. 

 Syn. Anthocrinus Loveni Joh. Miiller, 1853, Abh. d. Berl. Akad. d. 

 Wissensch., p. 192, PI. VIII, figs. 1— 11.— Pictet, 1857,Traite 

 de. Paleont., Vol. IV, PI. c, figs. 8 a, b, c. — Dujardin and 

 Hupe., Hist. uat. Zooph. Echinod., p. 117. — Quenstedt, 1885, 

 Handb. d. Petrefactenk., IV, p. 943, PL 15, fig. 4. 

 Upper Silurian, Gothland, Sweden, and Dudley, Eng. 

 1821. Crotalocrinus rugosus Miller, {Cyathocrinus rugosus), Nat. 

 Hist. Crin., p. 89., with plate. — 1837, Hisinger, ( Cyathocrinus 

 rugosus), Leth. Suec, p. 89, Tab XXV, fig. 3 ; also Antckn, 

 Heft IV, p. 217, PI. VII, fig. 3.-1839, Phillips (Cyatho- 

 crinus rugosus), Murchison's Silur, System, p. 672, PI. 18, fig. 

 1. — 1843, Austin, Ann. and Mag. Nat. Hist., Ser. 1, Vol. XI, 

 p. 198.— 1843, Morris, Cat. Brit. Foss., (Ed. I), p. 50.— 1850, 

 D'Orbigny, ( Cyathocrinus rugosus), Prodr. d. Paleont., Vol. 

 I, p. 46. — 1854, Salter, apud Murchison, Siluria, (Ed. 2), p. 

 219, (Ed. Ill, p. 247), figs. 4—7, and PI. 13, fig. 3.— 1855, 

 McCoy, Brit. Pal. Foss., p. 55.-1873, Salter, Cat. Mus. 

 Cambr., p. 123.-1878, Angelin, Icon. Crin. Suec, p. 26, PI. 

 VII, fig. 4; PI. XVII, tigs. 8, 8a. (not figs. 3, 3^).— 1879, 



