MANUAL OF THE MOLLUSCA. 



Pboserpiwella, Bland, I860. 



Etymology, diimniitive of Proserpina. 

 Type, P. Berendti, Bland. 

 Distribution, Mexico, 3000 to 4,000 feet. 

 Shell as in Proserpina ; coluniella fold absent ; aperture witli 

 one parietal lamelliform plait. 



[Family HELicnsTDja j 

 Contains : — 



Helicina [Lucidella, Trochatella, Alcadia). 



Schasicheila. Shell with, very close, long, spiral, epidermal 

 fringes. Bistrihution, 5 species. Central America and the 

 Bahamas. 



Perenna, Gruppy, 186Y ; P. lameUosa, Guppy, Trinidad. Shell 

 like Helicina, depressed ; whorls lirate and carinate. Operculum 

 thin, suboval, concentrically striated; nucleus subcentral. 

 Animal like Helicina, Distribution, 2 species. Trinidad, 

 Yucatan. 



BonRcrERA, Pfeiffer, 1851. 



Type, B. helicineeformis, Pf. 



Shell like Helicina, dull, and without the columellar callosity ; 

 columella toothed beneath. ; aperture ovate ; peristome spread- 

 ing. Lingual dentition agrees with, that of Helicina. Oper- 

 culum ovate, horny, few-whorled. 



Distribution, 2 species. South. America. 



Stoastoma, and 



Geoeissa, Blanford, 1864. 



Type, Hydrocena pyxis, Benson. 



Animal furnislied with, hemispherical lobes in the place of 

 tentacles ; eyes normal ; foot short, rotund. Operculum semi- 

 oval, no spiral structure as in Helicina ; excentrically striated, 

 testaceous, transparent. 



Shell resembling that of Hydrocena, imperforated, small, 

 conical, amber-, or reddish-coloured, spirally sulcated or striated. 



Distribution, 6 species. Adhering to limestone rocks, India. 



[Family AcicuLEDiE.] 



The genera enumerated in this family are : — Acicula, Geo- 

 MELANiA, Chittya, and Tetin'CATELla, the last with the foUow- 

 ing 

 50 



