2l8 SMITHSONIAN INSTITUTION 



The Species of Sagenocrinus 



I. Sutures between brachials usually straight. 

 RA completely between BB, touching IBB. 

 Arms strong ; RR largest plates in calyx. 



Plates without ridges .S". expansus. 



Median ridge upon RR and Br plates S. clarki. 



II. Sutures between Br distinctly sinuous. 



RA only partly between BB, not touching BB. 

 Arms delicate ; BB largest plates in calyx. 



Plates without ridges S. americanus. 



Sagenocrinites giganteus Austin is not distinguishable from S. expansus. 



Sagenocrinus expansus (Phillips) 

 Plates XVIII, figs, i-g; XIX, figs, i-j 



Actinocrinites (?) expansus Phillips in Murchison, Silurian System, 1839, p. 674, pi. 17, fig. 9; Palaeozoic 

 Fossils Cornwall, 1841, p. 29. — Quenstedt, Petref. Deutschlands, IV, 1876, p. 594. 



Sagenocrinites expansus, Austin and Austin, Ann. and Mag. Nat. Hist, X, 1842, p. no; ibid., XI, 1843, 

 p. 205. 



Sagenocrinus expansus, Morris, Catalogue British Fossils, 1st Ed. 1843, p. 58 (2d Ed., 1854, p. 89). — 

 Pictet Traite Paleontologie, IV, 1857, p. 323. — Angelin, Icon. Crin. Sueciae, 1878, p. 8, pi. 15, figs. 6, 

 8, and ?P1. 27, figs. 8a, b, ?P1. 28, fig. 8. — Wachsmuth and Springer, Revision Palaeocrinoidea, pt. 2, 

 1881, p. 203 ; N. A. Crinoidea Camerata, 1897, p. 219. — Springer, Jour. Geology, XIV, 1906, pi. 7, 

 figs. 18, 19. 



Carpocrinus expansus, Muller, Phys. Abhandl. K. Akad. Wiss. Berlin, 1843, p. 209. 



Glyptocrinus expansus, D'Orbigny, Prodrome Pal. Stratigraphique, I, 1849, p. 46. — Murchison, Siluria, 

 1859, p. 247 ; also Salter in appendix to same, p. 535. 



Glyptocrinus ? {Actinocrinites ?) expansus, Murchison, Siluria, 1859, pi. 15, figs. 1, 2. 



Rhodocrinites verus Miller (in part), Nat. Hist. Crinoidea, 1821, p. 107, pi. I, fig. — * 



A 



Rhodocrinus verus, Roemer in Bronn, Lethaea Geognostica, 1852-1854, p. 241, pi. 4, figs. 2a-e. 



Sagenocrinites giganteus Austin and Austin, Ann. and Mag. Nat. Hist., X, 1842, p. no; ibid., XI, 1843, 



p. 205. 



Type of the genus. 



Specimens attaining a large size. Crown oblong, with arms infolding. 

 Calyx turbinate to hemispheric, with side outline more or less curved; widest 

 at IIBr 3 , where cross-section is circular, or slightly decagonal from the depres- 

 sion of iBr and illBr spaces; height to width, about i to 1.2. Plates evenly- 

 curved, without radial ridges; smooth, or marked with crescentic wrinkles 

 parallel with margin of plates ; sutures straight and slightly beveled. Spread of 

 calyx from base to IIBr 3 , 1 to 5. Crown of large specimen, 85 mm. high by 

 53 mm. wide; base, 10 mm. ; small specimen, 15 mm. by 12 mm., base, 3 mm. 



IBB visible as low pentagons in side view. BB smaller than RR; post. B 

 but little different in shape from others. RA a pentagonal plate, truncate below 

 and of variable width where touching IBB, and angular above where it meets 

 the anal plate and r. post. R. iBr in 6 to 9 ranges before passing into the tegmen ; 

 the first plate angular above, supporting two vertical series of gradually dimin- 

 ishing plates which extend between and beyond the arm bases, and curve inward 

 upon the tegmen without visible interruption ; a third series is often interposed 



