140 PHYSA. 
Length 10, diam. 6 mill. 
Gila River, and near San Diego and Los 
Angelos, California. 
** Whorls shouldered. 
17. PHYSA HUMEROSA, Gould. 
Plate 6, figs. 8, 9, 10. 
Shell subrhomboidal, solid, smooth and 
white; spire acute; whorls five, tabulated ; 
aperture equaling one-half to two-thirds the 
shell’s length, rounded posteriorly; labrum 
expanded; columella scarcely plicate, callus 
hardly perforated. 
Length 15, diam. 9 mill. 
Colorado Desert. 
The whorls are not regularly tabulated as 
in certain Australian species and like Ph. 
- scalaris, but are simply perceptibly shouldered. 
(56) 
