Hkkde.] Carboniferous Invertebrates. 37 



deep reentrant angles, giving it the appearance of four vertical 

 tubes closely placed. In young specimens it is more round and 

 less rough than in the adult. The plates are so closely united 

 that it is difficult to make out their exact outline, but they are 

 very convex on the exterior. The upper plates in young speci- 

 mens are almost smooth, becoming more highly ornamented as 

 the base is approached, while on old specimens the plates are 

 highly tuberculated and the sides are ornamented by raised 

 ridges which seem to surround apertures in the plates. 



Height. Width. 



Infrabasals 3J mm. ,3 mm. 



Basals 5J " 6 " 



Radials o\ " 9 " 



Interradial 4 " 5 " 



First costals 2\ " 8 " 



Second costals 3 " 7 " 



Distichals 3.'. " 5 " 



Proboscis 58" " 11 " 



Range and distribution : Upper Coal Measures ; Kansas City 

 and Argentine. 



ERISOCRINUS. 



Meek and Worthcn. Am. Jour. Sci., LXXX, p. 174, (1865). 



Erisocrinus megalobrachius. Plate VII, figs, la, lb. 



Erisoerinus megalobrachius Beede, KaDs. Univ. Quart., vnr, p. 124, pi. 

 xxxii, fT. la, b. 



Calyx basin-shaped, quite concave, ornamented by very 

 coarse granulations, which are sometimes arranged in wavy 

 rows. Infrabasals unknown, covered, or nearly so, by the 

 small column. Basals large, convex, the lower portion curved 

 upward to meet the infrabasals forming a deep cavity in the 

 base of the cup, the inner (or lower) end of the basals being in 

 about the same horizontal plane as the upper end, and hence 

 forming most of the base of the calyx and leaving the infra- 

 basals entirely within the body cavity; higher than wide, all 

 about equal, and apparently pentagonal, the lower side ( or 

 s, if two ) short, superior and inferior lateral edges nearly 

 equal, the apical angle extending upward between the radials 

 to fully one-half the height of the latter. Radials five, equal, 

 pentagonal, twice ;i- wide as high, massive, convex, consider- 

 ably beveled at the upper edge ; upper surface faceted for the 



