144 SMITHSONIAN INSTITUTION 



HOMALOCRINUS Angelin 



Plate VI 



Homalocrinus Angelin, Icon. Crin. Sueciae, 1878, p. 11. — Von Zittel, Handbuch Palaeontology, I, 1879, 

 P- 355'-; Grundziige Palaeontologie, 1895, p. 138. — Wachsmuth and Springer, Revision Palaeoc- 

 rinoidea, pt. 1, 1879, p. 35 ; ibid., pt. 3, 1886, p. 143. — Zittel-Eastman, Textbook Palaeontology, 

 1896, p. 164 (2d Ed., 1913, p. 203). — Jaekel, Zeitschr. deutsch. geol. Ges., XLIX, 1897, p. 46 

 (separate). — Bather, Rep. British Assoc, for 1898 [1899], p. 923; Treatise on Zoology (Lankes- 

 ter), pt. 3, 1900, p. 189. — Springer, Jour. Geology, XIV, 1906, p. 482. 



Leiocrinus Springer, Amer. Geologist, XXX, 1902, p. 95. 



A 



Fig. 13. Homalocrinus 



Lecanocrinidae with rays partly separated by solid plates arched over by 

 brachials, and with highly specialized base. Crown ovoid. Infrabasals very 

 large, enveloping basals to a variable extent. Radianal under right posterior, 

 ray within ring of basals, but may be concealed by the infrabasals. Anal x 

 followed by others. Interbrachials usually one large plate followed by others 

 smaller. Primibrachs two. Arms heterotomous ; rays divided into ten main 

 rami abutting above interbrachials, with ramules inside of dichotom. Column 

 short, tapering gradually toward the distal end. 



Genotype. Homalocrinus parabasalis Angelin. 



Distribution. Silurian, Wenlock beds; Gotland and England. 



The history and relations of this genus will be discussed under Calpiocrinus. 



