136 PHYSA. 



highly polished ; aperture moderate, ear- 

 shaped; labrura regularly curved, not thick- 

 ened internally ; columella much indented at 

 its insertion, scarcely folded, narrow, white, 

 first vertical, then truncately turning to the 

 right towards the base. 



Length 11, diam. 6 mill. 



Sacramento and Marysville, California. 



This shell in appearance is singularly 

 graceful and pleasing. Its very smooth, 

 shining surface, unmarked by growth-lines, 

 and its indented columella, are the most pro- 

 minent distinctive characters. 



12. PHYSA NUTTALLII, Lea, 



Plate 7, fig. 2. 



Shell inflated, rather thin, semi-transparent, 

 somewhat bright, whitish ; spire obtuse, 

 short ; sutures impressed ; whorls four, con- 

 vex, the last one large and inflated ; aperture 

 large, rounded, pale brown within the margin ; 

 (52) 



