CONCHOLOGIA CESTRICA. 99 



Station, Brandywine Creek, Schuylkill River, Chester 

 County; abundant. 



S. stamineum, CONRAD. 



Cyclas stamineum, Conrad, Amer. Jour., XXV., 1834. 



S. stamineum. [Prime.] 

 Fig, 199, 



Shell, stout, oval, full, anterior side abrupt, posterior 

 more distended; beaks very full, and prominent, distant; 

 dark brownish-yellow; interior bluish; strongly striate; 

 hinge margin curved; cardinal teeth nearly obsolete; 

 laterals strong. H. 9, W. 14, T. 7, mill. 



Station, tributaries of the Delaware River. 



S. fabalis, PRIME. 



Cyclas fabalis, Prime, Bost. Proc., IV., 1851. 



S. fabalis. [Prime.] 

 Fig, 200. 



Shell, transversely oval, almost equilateral, rounded, 

 posterior side rather abrupt ; beaks depressed, regularly 

 and moderately sulcated ; epidermis, greenish, or straw 

 color ; valves thin, blue within ; cardinal teeth small ; 

 laterals slight, the anterior more elevated, both nearly 

 on a line with the cardinals. H. n, W. 14, T. 6, mill. 



Station, Susquehanna River and tributaries. Lan- 

 caster County ; not common. 



