PHYSA. 151 



29. PHYSA HETEROSTROPHA, Say. 

 Hald. Monog. p. 23, t. 2, figs. 1—9. 

 Physa osculans, in part, Hald., t. 2, figs. 11, 12. 

 Physa plicata, DeKay. Plate 8, fig. 7. 



Mr. W. G. Binney includes also in the 

 synonymy of this species P. aurea, Lea, which 

 I believe to = P. Troostiana, Lea, and P. 

 cylindrica, Newcomb, which I consider a syno- 

 nym of P. gyriiia, Say. P. infiata, Lea, also 

 placed here by Mr. Binney, is very probably 

 distinct from all other species, and I have so 

 treated it. Li conclusion, Mr. B. includes in 

 his catalogue of specimens in the Smithsonian 

 Museum several lots having west-coast locali- 

 ties, and none of these are really P. heterostro- 

 pha, which does not extend westward of the 

 great plains and Rocky Mountains. P. Tietero- 

 stroplia very rarely extends westward of the 

 Mississippi River or southward of the Ohio and 

 Potomac, and even at these Ijoundaries it is 

 largely replaced l^y other species. 



(67) 



