148 PHYSA. 
fourths the shell’s length, liver-brown within ; 
columella straight and thin. 
Length 19, diam. 12°65 mill. 
Lake Superior. 
A remarkably inflated species, most like P. 
ancillaria or P. Sayi; it is well distinguished 
by its more globose form, and its peculiar 
color. 
26. PHYSA HETEROSTROPHA, Say. 
Hald. Monog. 23, t. 2, figs. 1-9. 
With this species, following Mr. Binney, | 
unite Ph. plicata, DeKay, but I incline to 
consider Ph. inflata, Lea, distinct, or at least 
its identity is not proven. As for Ph, cylin- 
drica, Newcomb, and Ph. aurea, Lea, they are 
both of very different affinities, and are 
wrongly placed in the synonymy of Ph. hetero- 
stropha by Mr. Binney. 
(64) 
