42 VALVATA. 



4. VALVATA VIRENS, Tnjon. 

 Plate 16, fig. 4. 



Shell turbiniform, consisting of four well- 

 rounded whorls ; spire elevated, apex acute, 

 sutures deeply indented, periphery almost 

 angulated ; umbilicus very wide ; aperture 

 oval or nearly round, the peristome merely 

 touching the body above. Surface closely 

 striate. Color varying from brilliant to dark 

 green. 



Alt. 5, diam. 5 mill. 



Clear Lake, and other localities in Califor- 

 nia ; Lake Utah. 



Darker in color, and more turbmiform than 

 either of the preceding species. 



Subgenus L YOG YRUS, Gill, 



Shell elongated, whorls convex, the last 



partially disjointed from the spire ; aperture 



rounded. 



[15] 



