AND OTHER FAMILIES. 141 



with undulations. In the possession of many folds, it resembles the 

 U. muUiplicatus (nobis), but differs in outline (being much less trans- 

 verse), as well as in the size of the undulations, which are much smaller. 

 The point of its greatest diameter is much nearer the posterior basal 

 margin than in the muUiplicatus. The imperfect state of this speci- 

 men has prevented me from describing the ligament. Judging from 

 its elevated wing, I am much inclined to believe that when perfect 

 specimens are procured they will be found to be connate. If so, it 

 will belong to a natural division removed from Unio, viz. Symphynota. 

 I have dedicated this fine species to my friend P. H. Nicklin, Esq., of 

 Philadelphia. 



Unio capillaris. Plate II. fig. 2 



»• 



Testa suborbiculaid, ventricosd, subsequilaterali, postice subnngulatd ; valvulis 

 subcrassis; natibiis prominentibus ; epidermide 7iitide riigald; radiis numerosis 

 capillaribusqite ; dentibus cardinalibus valde elevatis ; lateralibus lamellatis et su7'- 

 sum subreclivis ; margaritd albd et iridescente. 



Shell suborbicular, ventricose, subequilateral, subangular posteriorly; valves rather 

 thick; beaks elevated ; epidermis finely wrinkled ; rays numerous and capillary ; car- 

 dinal teeth much elevated ; lateral teeth lamellar, and inclined to curve upwards; nacre 

 pearly white and iridescent. 



Hab. Ohio. T. G. Lea. 



My Cabinet. 



Cabinet of the Academy of Natural Sciences of Philadelphia. 



Diam 1-2, Length 1-5, Breadth 1-9 inches. 



Shell suborbicular, ventricose, subequilateral, subangular posteriorly ; 



substance of the shell rather thick anteriorly; thinner posteriorly; 



beaks thick and elevated ; ligament short and thick ; epidermis dark 



and finely wrinkled, smoother towards the beaks; rays numerous, 



capillary, and spreading over nearly the whole disk; cardinal teeth 



elevated, crenate, deeply cleft in the left valve, and rising from a pit 



in the right ; lateral teeth lamellar, crenate, inclined to turn upwards ; 



anterior cicatrices distinct; posterior cicatrices confluent; dorsal cica- 



38 



