94 CONCHOLOGIA CESTRICA. 



A. fluviatilis, DILLWIN. 



Mytilus fluviatilis, Dillwin, Descr. Cat. Shells, 1817. 



Anodon fluviatilis. 



Fig, 192, 



Shell, thin, fragile, oblong-ovate, ventricose; epider- 

 mis olive-brown, rayed with green ; hinge margin ele- 

 vated ; beaks at the anterior third of the length ; nacre 

 bluish-white. H. 2.75, W. 5, T. 2, inches. 



Station, in all the larger streams, especially in mill- 

 dams. Chester County; abundant. 



A. implicata, SAY, New Harm. Dis., II., 1829. 



A., implicata, 



Fig, 193, 



