552 PROCEEDINGS OF THE ACADEMY OF [NoV.^ 



This is Lampsilis leptodon Raf. of Simps. Synops., p. 575, Descr. 

 Catal., p. 188. 



Lampsilis fragilis Raf. 



Uniofragilis (Elliptio fragilis) Raf. Monogr. (1820), p. 295, No. 16. 



The type is A. N. S. P. Coll. No. 20,209, from creeks in Kentucky. 

 Length 97, height 64, diam. 32 mm. 



This is Lampsilis gracilis Bar. (1823) of Simps. Synops., p. 573, 

 Descr. Catal., p. 182. 



Lampsilis alatus Say. 



Metaptera megaptera {Unio megaptera) Raf. Monogr. (1820), p. 300, No. 17, 

 Pi. 80, figs. 20, 21, 22. 



The type is A. N. S. P. Coll. No. 20,211, from the Ohio River. 

 Length 141, height 100, diam. 50 mm. 



This is Lampsilis alatus Say (1816) of Simps. Synopsis, p. 567, 

 Descr. Catal., p. 162. 



Obovaria retusa Lam. 



Obovaria torsa {Unio torsa) Raf. Monogr. (1820), p. 311, No. 46, PL 82, 

 figs. 1, 2, 3. 



The type is A. N. S. P. Coll. No. 20,256, from the Kentucky River. 



Length 56, height 57, diam. 36 mm. 



This is Obovaria retusa Lam. (1819) of Simps. Synops., p. 599,, 



Descr. Catal., p. 290. 



Obovaria subrotunda Raf. 



Obliquaria subrotunda {U. subrotunda) Raf. Monogr. (1820), p. 308, No. 38, 

 PL 81, figs. 21, 22, 23. 



This shell is A. N. S. P. Coll. No. 20,254, from the Kentucky River. 

 Length 26.5, height 25.5, diam. 19 mm. 

 This is not Unio subrotunda Lea (1831). 



Obovaria striata {Unio striata) Raf. Monogr. (1820), p. 311, No. 47. 



The type is A. N. S. P. Coll. No. 20,205, from the Ohio River. 



Length 44, height 41.5, diam. 27.5 mm. 



This is not Uriio striata Lea (1840). 



These two shells are Obovaria circulus Lea (1829) of Simps. Synops., 

 p. 600, Descr. Catal., p. 291. 

 Obovaria levigata Raf. 



Unio levigata {Elliptio levigata) Raf. Monogr. (1820), p. 296, No. 9, PL 80, 

 figs. 11, 12, 13. 



The types are A. N. S. P. Coll. No. 20,255, from the Kentucky 

 River. 



Length 27, height 22, diam. 14 mm. 

 Length 25, height 21, diam. 13 mm. 



