1915.] NATUKAL SCIENCES OF PHILADELPHIA. 555 



Length 46.5, height 28, diam. 8 mm. 



This is Sijmplujnota viridis Conr. (1836) of Simps. Synops., p. 663, 

 Descr. Catal., p. 484. 



Unio dilatata Raf. 



Unio dilatata (EUiptio dilatata) Raf. Monogr. (1820), p. 297, No. 11. 



The types are A. N. S. P. Coll. No. 20,248, from the Kentucky 

 River. 



Length 76.5, height 42, diam. 24 mm. 

 Another specimen. No. 20,236. 

 Length 102, height 49, diam. 30 mm. 



Obliquaria sinuata {Unio sinuata) Raf. Monogr. (1820), p. 321, No. 67. 



The type is A. N. S. P. Coll. No. 20,252, from the Kentucky River. 



Length 110, height 61, diam. 37 mm. 



These shells are Unio gibhosus Bar. (1823) of Simps. Synopsis, p. 

 703, Descr. Catal., p. 597. This is not Unio gibhosus Raf. Monogr. 

 (1820), p. 315, No. 56. 



Unio crassidens Lam. 



Unio nigra {EUiptio nigra) Raf. Monogr. (1820), p. 291, No. 1, PI. 80, figs. 

 1, 2, 3, 4. , 



The type is A. N. S. P. Coll. No. 20,243, from the Ohio River, 



Length 73, height 47, diam. 30.5 mm. 



This is Unio crassidens Lam. (1819) of Simps. Synops., p. 706,. 

 Descr. Catal., p. 606. 

 Unio buxeus Lea. 



Unio pusilla Raf. (1820), p. 308, No. 39, is earlier than Unia 

 pusillus Lea (1840), but Unio buxeus Lea (1852) can be used for the 

 species. Simps. Synops., p. 708, Descr. Catal., p. 611. 



Pleurobema clava Lam. 



Unio elliptica {EUiptio elliptica) Raf. Monogr. (1820), p. 296, No. 8. 



The type is A. N. S. P. Coll. No. 20,213. 

 Length 34, height 29, diam. 29.5 mm. 



Obliquaria scalenia [U. scalenia) Raf. Monogr. (1820), p. 309, No. 42, PI. 81, 

 figs. 24, 2.5. 



The type is A. N. S. P. Coll. No. 20,229, from Ohio. 



Length 54, height 35, diam. 26 mm. 



Pleurobema cuneata {Unio cuneata) Raf. Monogr. (1820), p. 313, No. .52. 



The type is A. N. S. P. Coll. No. 20,228, from the Ohio River. 

 Length 65, height 45, diam. 31 mm. 



These shells are all Pleurobema clava Lam. (1819) of Simps. Synops., 

 745, Descr. Catal., p. 735. 



