BRACHIOPODA—NEOTREMATA. 



207 



Surface 



Utica and Lorraine of Ohio, Indiana, Illinois, Wisconsin. 



57. C. setigera Hall. (Fig. 241, e-f.) Ordovicic. 

 Small; often with nearly straight cardinal margin 



marked with quite coarse pustules 

 or setae which are most distinct near 

 the margin of the shell. 



Trenton and Lorraine of Iowa, Il- 

 linois, Wisconsin, Minnesota. 



58. C. trentonensis Hall. (Fig. 

 241, c-d.) Ordovicic. 



Brachial valve thick, thus differ- 

 ing from C. scabiosa and not cov- 

 ered as in C. setigera with elongate 

 pustules. 



Trenton of New York, Illinois, 

 Wisconsin, Minnesota. 



59. C. laelia Hall. (Fig. 242.) 



Ordovicic. 



Small, moderately convex, apex of upper valve distant from mar- 

 gin one third diameter of shell ; surface with fine sharp striae, in- 

 creased sometimes by implantation. 



Utica to Lorraine of Ohio and Indiana. 



Fig. 241. a, b, Schizotreta pelopea, 

 dorsal and ventral valves, the latter 

 showing small oval pedicle opening ; 

 c, d, Crania trentonensis, dorsal and 

 profile views ; <?, f, Crania setigera, 

 dorsal and profile views. (After 

 Winchell and Schuchert.) 



Fig. 242. Crania Icelia, four indi- 

 viduals attached to shell of Strophomena 

 planumbona, X *• (After Hall and 

 Clarke. ) 



Fig. 243. Crania crenistriata, lat- 

 eral and top views of an elliptical dor- 

 sal valve, X I- (After Hall.) 



60. C. crenistriata Hall. (Fig. 243.) Devonic. 



Brachial valve depressed conical. Surface marked by elevated, 

 crenulate, radiating striae which reach nearly to the smooth 

 apex. 



Onondaga and Hamilton of New York, Ohio, Kentucky, 

 Michigan. 



