SAGENOCRINIDAE 



211 



MERISTOCRINUS Springer 

 Plate XVII, figs, i-p 



Meristocrinus Springer, Jour. Geology, XIV, 1906, pp. 515, 519. — Bather, Ann. and Mag. Nat. Hist., 



(8) XII, 1913, p. 389. — Zittel-Eastman, Textbook Paleontology, 1913, p. 204. 

 Cyathocrinus, Angelin (in part), Icon. Crin. Sueciae, 1878, p. 23 (not Miller). 

 Gnorimocrinus Wachsmuth and Springer (in part), Revision Palaeocrinoidea, pt. 1, 1849, p. SO. 



Fig. 23. Meristocrinus 



Sagenocrinidae with rays above radials separated by perisome with or 

 without a few solid plates in lower part. Crown elongate, expanding above 

 radials. Infrabasals recumbent, taking small part in the formation of the calyx 

 wall. Radianal usually in form of an infer-radial under right posterior ray. 

 Anal x followed by others in series tending to form a tube. Interbrachials few 

 and small (or wanting) in lower part of areas, followed by perisome. Primi- 

 brachs three. Arms dichotomous, divergent. Column large, expanding toward 

 calyx. 



Genotype. Cyathocrinus intcrbrachiatus Angelin. 



Distribution. Silurian; Gotland and England. 



This genus is the least satisfactory of those proposed by me in 1906, and the species now 

 grouped under it are a sort of hodge-podge of forms for which no better place is found. We 

 are embarrassed by abnormal or imperfect specimens in most of the species, and it is by no 

 means certain that they all belong together. The genus was proposed mainly to receive some 

 Silurian forms with a radianal and three primibrachs. Species so constructed might perhaps, 

 in conformity with what has been found advisable in some other cases, be treated as variants 

 of genera with a radianal and only two primibrachs, and would then fall under either Temno- 

 crinus, Protaxocrinus or Gnorimocrinus. But the species here grouped do not exactly agree 

 with any of those genera in other details, so I have concluded to let the genus stand for what 

 it is worth. The species designated by me as the type of Meristocrinus was the form orig- 



