COCHLIOPA. 59 
Genus COCHLIOPA, Stimpson. 
1. COCHLIOPA ROWELLIL, Zryon. 
Plate 17, fig. 8. 
Shell depressed, wider than high, consisting 
of 33 whorls, which are regularly convex and 
rapidly enlarging; spire small, but little eleva- 
ted, apex acute, sutures well marked; base 
convex, except that the region surrounding the 
umbilicus is flattened and inclining towards 
the axis, its outer boundary, consequently, is 
marked by an angle; umbilicus small, but very 
distinct; aperture half ovate, the labrum well 
rounded and thin, the labium but slightly 
rounded, thickened, elevated from the body 
whorl, forming an acute angle with the labrum 
above, and not impinging on the umbilicus. 
Color yellowish-green. Operculum paucispiral. 
Alt. 2°5; diam. maj. 4, min. 3 mill. 
Clear Lake, California. 
(40) 
