126 



obtusely angular : aperture ovate, acute above, with an ex- 

 tremely thick deposit on the inner side, with a very large com- 

 pressed columellar fold. 



Mean divergence 50° ; length 1.33 inch ; breadth .7 inch ; 

 length of aperture .61 inch. 



The unique specimen which has served for this description 

 is somewhat faded, and the lip probably is not quite mature, 

 being sharp. 



AcHATiNELLA Tappaniana. Shell rcvcrscd, elongate ovate- 

 conic : pure white, with one narrow brown spiral band on the 

 periphery of the last whorl : with very unequal and irregular 

 transverse striae, and numerous excessively minute wrinkled 

 spiral impressed lines : apex subacute : spire elongate, with 

 the outlines a little curvilinear : whorls nearly seven, moder- 

 ately convex, and more or less subangular, margined above, 

 with a well impressed suture : aperture ovate ; lip well thick- 

 ened within the margin, expanded much anteriorly but not 

 above ; columellar fold strong. 



Mean divergence 43° ; length 1.06 inch ; breadth .55 inch ; 

 length of aperture .44 inch. 



Var. dubiosa differs in being a little more ventricose ; its 

 whorls are not margined above, and the brown stripe is re- 

 placed by two fine paler brown lines, below which one or two 

 other yet finer lines may be seen. 



Habitat, Sandwich Islands. 



This beautiful species is named in honor of Hon. Benja- 

 min Tappan, of Ohio. 



AcHATiNELLA DiMONDi. Shell rcvcrsed, thick, long ovate- 

 conic : dingy white or very pale yellowish brown, with a 

 blackish margin to the aperture when mature ; with a green- 

 ish black fugacious epidermis : with the transverse striae 

 rather slight, very unequal and irregular, without spiral striae : 

 apex subacute : spire rather long, with the outlines moderately 



