OF THE FAMILY OF NAIADES. 455 



8. Symphynota Ochracea. 



Testa, sub-ovatd, incequilaterali, transversim rugosd, inflatd; valvulis 

 post ligamentiim connalis, tenuibus, fragilibus, et sine aid ; dentibus 

 cardinalibus et lateralibus curvam lineam facientibus ; natibus promi- 

 nentibus ; ligamento conspicuo ; margaritd coeruleo-albd et ochracea. 



Shell sub-ovate, inequilateral, transversely wrinkled, inflated ; valves 

 thin and fragile, connate behind the ligament, not winged ; cardinal and 

 lateral teeth forming a curve line ; beaks prominent ; ligament visible ; 

 nacre bluish-white and ochraceous. 



Hab. Schuylkill and Delaware. 



My Cabinet. 



Cabinet of Mr Say. 



Cabinet of Prof. Vanuxem. 



Cabinet of Mr Hyde. 



Cabinet of the Academy of Natural Sciences. 



Cabinet of Dr Griffith. 



Cabinet of P. H. Nicklin. 



Peale's Museum. 



Unio ochraceus. Say. Nicholson's Encyclopaedia, Art. 



Am. Conchol. pi. 2, fig. 8. 



Diam. 1-3, Length 1-9, Breadth 2-9 inches. 



Shell sub-ovate, inequilateral, transversely w^rinkled, infla- 

 ted ; dorsal margin rectilinear ; valves thin and fragile, con- 

 nate behind the ligament, not winged; beaks full and pro- 

 minent, with several concentric undulations ; ligament not 

 concealed; epidermis glossy, varying from yellow ochre to 

 brown ochre, marked with oblique rays, most abundant 

 behind; cardinal and lateral teeth lamelliform, forming a 

 curve line, in the right valve the cardinal tooth is double, 

 in the left single ; anterior cicatrices distinct ; posterior cica- 

 trices confluent ; dorsal cicatrices form a row across the ca- 

 vity of the beaks, very perceptible ; cavity of the beaks large ; 

 nacre bluish-white and ochraceous; along the anterior basal 

 margin thicker and tinged with red; posterior margin iri- 

 descent. 



VOL. III. — 5 z 



