BRACHIOPODA—PROTREMATA. 



225 



and close radiating striae, usually several smaller between two 

 larger, the smaller being always shorter than the larger. 



Fig. 272. a (upper), Strophomena trcntonensis ; b, Strophomena neglecta ; dorsal 

 views. (After Hall.) 



Lorraine of Ohio, Indiana, Kentucky, Missouri, Wisconsin, 

 Minnesota, Manitoba, Anticosti. 



100, a. S. rugosa var. subtenta (Hall). Ordovicic. 



Differs from 5. rugosa in being obliquely wrinkled along the 

 cardinal margins. 



Occurs with the preceding in the Lorraine of Ohio, Indiana, 

 Kentucky, Missouri, Minnesota and Anticosti. 



XXXVI. Lepttena Dalman. 

 Very similar to Rafinesquina, but wider in proportion to its 

 length and usually with the flatter portions of the valves marked 



Fig. 273, a. Leptcena rhomboidalis (Niagaran type.) 



with conspicuous concentric wrinkles ; where these cease the shell 



