16 On the Family Proserpinacea. 



4. P. gioJmlosa ©rfoig-iiy. 



— apertura bidentata : " clentibus approximates, altero lamellseforrni, 

 intrante in pariete aperturali, altero acuto in columella." 



Hub. — Isle of Pines ; also Cuba. 



«>. P. des>ressa ©rJkigaiy. 



— apertura bidentata : " dentibus approximatis, altero lamellaeformi, 

 intrante in pariete aperturali, altero acuto in columella." 



Hah. — Cuba. 



6. P. hidesifatia C. 15 > Adanns. 



— " apertura dentibus 2 instructa, altero prope basin columella?, 

 altero paulo supra eum." 



Hub. — Jamaica. 



It will be noticed that the existence of one or more parietal 

 or palatal teeth, in addition to the fold or tooth on the colu- 

 mella, is given as a characteristic of the Family. 



The recent discovery, however, of the species described in 

 this paper as P. Swifti, having the columellar fold only, shows 

 that it alone, so far as the teeth are concerned, is a constant 

 character. 



P. Swifti does not properly belong to Proserpina as defined 

 by authors, but as that genus embraces sj>ecies with and with- 

 out palatal teeth, it may fairly be enlarged so as to include 

 those with and without parietal teeth, all having the colu- 

 mellar fold characteristic of the family. There are, however, 

 other differences which might warrant my placing the species 

 in a new Genus. 



Proserpisaa Swifti, n 



ov. SI 



T. depressa, tennis, nitidissima, diaphana, fulva ; spira vix elevata ; 

 sutnra distincte impressa ; anfr. 5 lente accrescentes, nltimus latns, basi 

 convexiusculus, juxta columellara excavatus ; apertura lunaris, plica den- 

 tiformi, acuta, in columella mnnita; perist. simplex, tenue. 



