TAXOCRINIDAE 



417 



ONYCHOCRINUS Lyon and Casseday 

 Plates LXIV-LXXIV, LXXV, figs. 14, 13; text-fig. 8 



Onychocrinus Lyon and Casseday, Amer. Jour. Sci., (2) XXIX, i860, p. 77. — Meek and Worthen, Proc. 

 Acad. Nat. Sci. Philadelphia, 1865, p. 140, footnote; ibid., 1866, p. 255; Geol. Surv. Illinois, II, 1866, 

 p. 242. — Wachsmuth, Amer. Jour. Sci., (3) XIV, 1877, p. 185 ; Ann. and Mag. Nat. Hist., (5) I, 

 1878, p. 457. — Von Zittel, Handbuch Palaeontologie, I, 1879, p. 353 ; Grundziige Palaeontologie, 

 1895, p. 138. — Wachsmuth and Springer, Revision Palaeocrinoidea, I, 1879, p. 53; ibid., pt. 3, 1886, 

 p. 145 ; Proc. Acad. Nat. Sci. Philadelphia, 1888, pp. 344, 353 ; ibid., 1890, pp. 353, etc. — Miller, 

 ' N. A. Geol. and Palaeontology, 1889, p. 264. — Zittel-Eastman, Textbook Paleontology, 1896, p. 163, 

 2d Ed., 1913, p. 206. — Jaekel, Zeitschr. d. deutsch. geol. Gesell., for 1897 [1898], p. 46. — Bather, Rep. 

 Brit. Assoc, for 1898 (1S99), p. 923; Treatise on Zoology (Lankester), pt. 3, igoo, p. 190. — Springer, 

 Amer. Geologist, XXX, 1902, p. 95; Jour. Geology, XIV, 1906, p. 519. 



Oligocrinus Springer, Amer. Geologist, XXX, 1902, p. 95 ; Jour. Geology, XIV, 1906, p. 519. 



% 



Fig. 51. Onychocrinus 



Taxocrinidae with rays more or less widely separated above interbrach- 

 ials. Infrabasals low, usually exposed beyond- the column. Posterior basal 

 elongate. Radianal, if present, only in upper oblique position. Interbrachials 

 variable, few to very numerous. Primibrachs three or more. Arms heteroto- 

 mous, in ten main trunks bearing ramules. Column enlarging next to calyx. 



Genotype. Onychocrinus exsculptus Lyon and Casseday. 



Distribution. Lower Carboniferous, Lower Burlington and equivalents 

 to Kaskaskia; the United States and Great Britain. 



