148 PHYSA. 



fourths the shell's length, liver-brown within ; 

 columella straight and thin. 



Length 19, diam. 12-5 mill. 



Lake Superior. 



A remarkably inflated species, most like P. 

 (inciUaria or P. Sayi ; it is well distinguished 

 by its more glolx)se form, and its peculiar 

 color. 



26. PHYSA HETEROSTROPHA, Say. 



Hald. Monog. 23, t. 2, figs. 1—9. 



With this species, following Mr. Binney, 1 

 unite Ph. plicata, DeKay, but I incline to 

 consider Ph. iiijiata, Lea, distinct, or at least 

 its identity is not proven. As for Ph, cylin- 

 drica, Newcomb, and Ph. aurea, Lea, they are 

 l)oth of very different affinities, and are 

 wrongly placed in the synonymy of Ph. Jiefero- 

 stropha by Mr. Binney. 



(64) 



