OF THE FAMILY OF NAIADES. 1 . 



8. Sv.MPIIVNOTA OciIRACEA. 



Test ti sub-ovatd, iiwquilatcrali, transversim rugosii, in/lot <i : raluulis 

 post ligamentum connatis, tenuibus, fragilibus, et sine aid ; dentibtu 

 cardinalibus et lateralibvs curvam lineam facientibtu; natibus promi- 

 nentibus ; ligamento conspicuo ; margaritii citrulco-albu et ockraa 



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

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

 lateral tcetli forming a curve line; beaks prominent; ligament visible: 

 nacre bluish-white and ochraccous. 



Hab. Schuylkill and Delaware. 



My Cabinet 



Cabinel of Mr Say. 



Cabinet of Prof. Vannxem. 



Cabinet of Mr Hyde. 



Cabinet of the Academy of Natural Sciences. 



Cabinet of Dr Grillith. 



Cabinet of P. H. Nicklin. 



Peak's Museum. 



Unio ochraceus. Say. Nicholson's rhicyclopa-dia, Art. 



Am. Conehol. pi. 2. fig. 8. 



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



Shell sub-ovate, inequilateral, transversely wrinkled, infla- 

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

 nate behind the ligament, not winged; beaks lull 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 lainrllil'nnii. forming 8 

 curve line, in the right valve the cardinal tooth i> double, 

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

 trices confluent : dorsal cicatrice-- farm m row across the ca« 

 vity of the beaks, verj 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 



