PHYSA. 



187 



outer lip sharp and very much expanded ; 

 columella slightly thickened and twisted. 



Length 10, diam. 6-5 mill. 



Lewis' River, Oregon. 



This species differs from all other American 

 Physce in having a regularly arched outer lip. 

 It approaches Say's ancillaria^ but it has not 

 the shoulder, and is rather more oblique. It 

 seems to be quite a different species from con- 

 color, Hald., also brought by Prof Nuttall 

 from Oregon, 



13. PHYSA CONCOLOR, Haldeman. 



Monog. p. 30, t. 2, fig. 10. 



This species is doubtless identical with some 

 of the other western species, but the single 

 type is entirely too small for identification. 



(53) 



