81 



ed, with a deep suture ; last whorl sliehtly flattened above the middle : 

 aperture in the form of a spherical triangle: labrum sharp: colu- 

 mella much and very obliquely produced, curved, very thick, abruptly 

 terminating, opaque white : umbilical region not indented. — This spe- 

 cies has been confounded with H. tenerrima, and distributed as such. 

 Greatest breadth .63 inch ; least breadth .56 inch ; height .47 inch. 



Phoserpina discoidea. Shell nearly discoidal : pale yellowish 

 or greenish brown ; subtransparent, shining : with excessively tine 

 striae of growth, and an impressed spiral line next below the suture : 

 spire convex, slightly elevated : whorls four and one-half, moderately 

 convex, with a well impressed suture ; last whorl a little flattened 

 beneath : aperture much dilated laterally, transversely ovate, but much 

 modified by the penult whorl, without teeth : labrum thin and sharp : 

 central callus occupying the region of the umbilical indentation : um- 

 bilicus narrow and deep. — This species is nearly allied to P. opalina. 

 Being a genuine Proserpina without teeth, it suggests the propriety of 

 omitting the phrase " apertura intus dentata" from the description of 

 the genus. 



Greatest breadth .275 inch ; least breadth .23 inch ; height .09 

 inch. 



Proserpina pulchra. Shell similar to P. nitida^ but much 

 smaller and less discoidal, the spire being more elevated and the last 

 whorl higher : the color of the upper whorls, (the last and usually a 

 small part only of the penult whorl being excepted), varies from a 

 deep crimson to a bright orange red, with an opaque white line along 

 the suture. In all other characters this shell so closely resembles P. 

 nitida, that I have long hesitated whether I should propose it as a dis- 

 tinct species. The peculiarity of form appears to be absolutely con- 

 stant in the individuals (about 30), that I have seen : that of color 

 fails partially only in a very few, which appear to have been bleach- 

 ed by exposure. 



Greatest breadth .2 inch ; least breadth .18 inch ; height ,12 inch. 



Proserpina bidentata. This shell is also very similar to P. 

 m<i</a, but is much smaller: besides the deep spiral line which ac- 

 companies the suture, there are several other very feebly impressed 

 spiral lines ; the surface is not so smooth although equally brilliant ; 

 the color is yellowish green : the aperture has only two teeth, one 

 near the base of columella, and another a little above it. Specimens 



