Vitrinella zncgastoma Adams. 



V. t. depressa, transverse ovata, alba, translucente, laevi, nitida : 

 apice obtusa : spira convexa anfractibus tribus, subconvexis, sutura 

 conspicua; anf. ultimo prope aperturam maximo, regulariter rotun- 

 dato. 



Much depressed, transversely ovate : 



white, translucent : 



smooth and shining : 



apex very obtuse : 



spire convex, but little elevated : 



whorls a little more than three, moderately convex, with a 

 distinct suture ; last whorl very large, rapidly increasing in the 

 last part, well rounded : 



aperture scarcely modified by the last whorl : 



umbilical region ver}' widely and deeply indented. 



Mean divergence about 130° ; length of spire .01 inch ; 

 total length .033 inch ; greatest breadth .06 inch, least breadth 

 .045 inch. 



