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, calluKS 

 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) 



