MANUAL OF THE MOLLUSCA. 
PROSERPINELLA, Bland, 1865. 
Ktymology diminutive of Proserpina. 
Type, P. Berendti, Bland. 
Distribution, Mexico, 3000 to 4,000 feet. 
Shell as in Proserpina; columella fold absent; aperture with 
Gne parietal lamelliform plait. 
[Famity HELIcinIpz} 
Contains :— ; 
H=Eticina (Lucidella, Trochatella, Alcadia). 
Schasicheila. Shell with very close, long, spiral, epidermal 
fringes. Distribution, 5 species. Central America and the 
Bahamas. : ; 
Perenna, Guppy, 1867; P. lamellosa, Guppy, Trinidad. Shell 
‘ike Helicina, depressed ;- whorls lirate and carinate. Operculum 
thin, suboval, concentrically striated; nucleus subcentral. 
Animal like Helicina. Distribution, 2 species. Trinidad, 
Yucatan. 
BourciERA, 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 
GEORISSA, Blanford, 1864. 
Type, Hydrocena pyxis, Benson. 
Animal furnished 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 Mydrocena, imperforated, small, 
tonical, amber-, or reddish-coloured, spirally sulcated or striated. 
Distribution, 6 species. Adhering to limestone rocks, India. 
[Faminy AcICULID. | 
The genera enumerated in this family are :—AcIcULA, GEO- 
MELANIA, CHITTYA, and TRUNCATELLA, the last with the follow- 
ing 
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