28 DESCRIPTION OF NEW 



Unio notatus. Plate VIII. fig. 22. 



Testa. eWpticd, compressd, transversa, incBquilateraU, postice subbiangulatd ; vahulis te- 

 nuibus ; natibus subprominulis ; epidermide rufo-fuscd, vittatd; dentibus cardinalibus parvis ; 

 lateralibus longis subcurvisque ; margaritd salmonis colore iinctd et iridescente. 



Shell elliptical, compressed, transverse, inequilateral, behind subbiangular ; valves 

 ihin ; beaks rather prominent; epidermis reddish brown, spotted; cardinal teeth 

 small ; lateral teeth long and slightly curved ; nacre salmon colour and iridescent. 



Hab. Cumberland River. Professor Troost. 



Cabinet of Professor Troost. 

 Diam. -6, Length 1, Breadth 1-8 inches. 



Shell elliptical, compressed, transverse, inequilateral, subbiangular 

 behind ; substance of the shell thin ; beaks somewhat prominent ; liga- 

 ment rather short; epidermis reddish brown, with spotted rays over 

 the whole disk ; cardinal teeth small, pointed, and deeply cleft in the 

 left valve; lateral teeth long and slightly curved ; anterior cicatrices 

 distinct; posterior cicatrices confluent; dorsal cicatrices placed in the 

 centre of the cavity of the beaks ; cavity of the shell rather shallow ; 

 cavity of the beaks angular ; nacre salmon colour and very iridescent. 



Remarks. — Another of the fine shells sent by Professor Troost from 

 Tennessee. In outline it resembles U. Fanuxemensis herein described, 

 but is not so thick a shell, and differs in having rays (interrupted), 

 while the other has none. It is also much smaller in the teeth. The 

 individual before me not being perfect in the beaks, I cannot say if the 

 undulations be the same. 



Unio Jayensis. Plate IX. fig. 23. 



Testd angusto-elliplicd, transversa, valdi incequilaterali, postici subangulald ; vahulis te- 

 nuibus ; nalibus prominulis ; epiderrnide fused ; dentibus cardinalibus compressis; lateralibus 

 longis rectisque ; margaritd purpurea. 



Shell narrow-elliptical, transverse, very inequilateral, subangular behind; valves= 



