animal white. A similar species is found in the 

 river Susquehanna. 



SPECIES XIII. Unio solenoides (Elliptic 

 solenoides.} 



Shell elliptical, cylindrical, attenuated, round- 

 ed anteriorly ; retuse posteriorly ; thick, very 

 ventricose, with flexuous posterior wrinkles ; 

 epidermis olive brown; nacre bluish white; cardi- 

 nal tooth rugose, obtuse; lamellar tooth very 

 long, horizontal. Length f diam. T 4 T axis T 3 r 

 of the breadth. 



A very remarkable species, found in the upper 

 part of the Ohio. Breadth about three inches ; 

 apices prominent ;fossule visible. 



Var. 1. interrupta, with some blackish 

 lines interrupted or broken anteriorly. 

 Var. 2. nodosa with knots or nodosities 



posteriorly. 



Var. 3. cylindricus, SAY. Very thick, 

 nacre white, apices very large. 



Second Genus LAMPSILIS. 



Shell oval ; ligament curved, cardinal tooth 

 furrowed ; lamellar tooth curved, flexuous ; axis 

 extramedial ; marginal contour thickened ; three 



