VIVIPARA. 25 



12. VIVIPAKA NOLANI, Tryon. 

 Plate 12, figs. 10, 11. 



Ovate, imperforatej thick, spire short conic 

 or truncated; whorls 5, separated by a very 

 deep suture making a rounded shoulder on 

 each/ aperture subpyriform, the inner lip very 

 thick. Dark olivaceous, bluish or white 

 within. 



Length 33, diam. 24 mill. 



Coosa River, Alabama. 



Hitherto confounded with V. ponderosa, 

 this species is readily distinguished in all 

 stages of growth by its narrower and more 

 sloping whorls and deep sutures. 



13. VIVIPARA OBESA, Lewis. 



Plate 13, fig. 6. 



Obesely-ovate, very ventricose; whorls 5, 

 convex, spire short-conic, sutures well im- 

 pressed, aperture ovate. Dark olivaceous, 

 bluish-white within the aperture. 

 (51) 



