232 CATALOGUE OF THE BLASTOIDEA. 



with its very short radials, may be either a Granatocrinus like G. Derbiensis (PI. IX. 

 figs. 1, 6), a Schizoblastus like S. Sayi, or an Mceacrinus. But we cannot attempt to 

 give it a generic name in the absence of any detailed knowledge of its summit- 

 structure. G. projectus, on the other hand, which was formerly regarded by Meek 

 and Worth en only as a variety of G. melo 1 , is not improbably a Cryptoblastus. The 

 anal deltoid is more prominent than the others, which are comparatively small, while 

 the base is also slightly protuberant. These characters are more pronounced in 

 G. neglectus, M. & W., but it has rather larger deltoids 2 , and we cannot make out from 

 Meek and AVorthen's figure whether or not the posterior spiracles are confluent with 

 the anus. 



We recognize the following species of Cryptoblastus : — 



% Elceacrinus Kirkwoodensis, Shumard. St. Louis Limestone, Subcarboniferous ; 



Missouri. 

 Pentremites melo, O. & S. Burlington Group, Subcarboniferous; Iowa, Missouri, 



Illinois. 

 1. Pentremites melo, var. projectus, M. & W., var. Burlington Group, Subcarboni- 

 ferous ; Iowa. 

 Granatocrinus pisum, M. & W. Burlington Group, Subcarboniferous; Iowa, 

 Missouri. 



Distribution. The genus is exclusively confined to the Subcarboniferous of America, 

 the last three species in the above list belonging to the Burlington Limestone, while 

 Shumard obtained the first one from the St. Louis Limestone. 



Type. Pentremites melo, Owen & Shumard. 



Crtptoblastus melo, Owen & Shumard, sp. 

 (PL VII. figs. 14, 15.) 



Pentremites melo, Owen & Shumard, Journ. Acad. Nat. Sci. Philad. 1850, vol. ii. pt. 1, p. (55, 



t. 17. f. 4o-c. 

 Pentremites melo, Owen & Shumard, Wisconsin, Iowa, and Minnesota Geo). Report, 1852, 



p. 592, t. 5 a. f. 14, a-c. 

 Elceacrinus inrlo, Shumard, Trans. St. Louis Acad. Sci. 18G3, vol. ii. no. 1, p. 112. 

 Granatocrinus melo, Shumard, ibid. L865, vol. ii. no. 2, p. 375. 

 Granatocrinus melo. Meek & YVorthcn, Proc. Acad. Nat. Sci. Philad. 1869, p. 84 

 Schizoblastus melo, E. & O, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 2 16. 



Sp. Char. Calyx subglobose, or elongate-globular, resting on the radial lips; 

 summit flat, and wider than the base; peristome concave; base more or less 



i Proc. Acad. Nat. Sci. Philad. 1801, p. I 12. 



- l!q>ort Geol. Survey Illinois, 1873, p. 471, pi. 9. fig. 3. 



