42 VALVATA. 
4. VALVATA VIRENS, Tryon. 
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 turbiniform than 
either of the preceding species. 
a 
Subgenus LYOGY RUS, Gill. 
Shell elongated, whorls convex, the last 
partially disjointed from the spire; aperture 
rounded. 
[15] 
