ASOLENE. 349 



Syn. Lanites, Swains. 



Ex. L. Bolteuiana, Chemnitz, pi. 37, fig. 5. Opercu- 

 lum, L, Bolteniana, fig. 5, a, 5, h. 



The species of this genus are from the river Nile, 

 Zanzibar, and West Africa. The shell and operculum 

 only are known ; the latter is horny and nearly trans- 

 parent. 



Species of Lanistes. 



Bolteniaua, Chetn. intorta, Lam. 



Guineensis, Chem. Lybica, Morel. 



Genus MELADOMUS, Swaiuson. 



Operculum horny, sinistral. 



Shell sinistral, thin, imperforate, covered with a dark 

 olivaceous epidermis; spire produced, acuminated ; aper-- 

 ture oval, reversed, contracted and acute posteriorly, 

 entire in front, peristome thin, simple. 



Ex. M. olivaceus, Sowerhy, pi. 37, fig. 6. Operculum, 

 M. olivaceus, fig. 6, a, 6, h. 



This genus, the animal of which is at present unknown, 

 differs from Pomus and Ampullaria in being sinistral 

 and turreted. It is an inhabitant of the rivers of Africa. 



Genus ASOLENE, D'Orbigny. 



Siphon not exposed. 



Operculum horny, with an internal shelly coat. 



Shell globose, solid ; spire small, whorls rounded ; 

 aperture oval, entire ; inner lip slightly thickened, peri- 

 treme simple, acute. 



