LUCIDELLA. 307 



distinct fissure, generally curved, separating it from the 

 columella. 



Ex. A. Brownii, Gray, pi. 87, fig. 7. Operculum, A. 

 Brownii, fig. 7, a, 7, b. Shell, A. Brownii, fig. 7, c. 



Cuba, Jamaica, Haiti, and other West-Indian Islands are 

 the localities of this group, the shells of which are usually 

 covered with a velvety epidermis, and have a straight, 

 flattened columella ; the tooth-like process of the operculum 

 is adapted to the slit in the peritreme. 



Species of Alcadia, 



Brownii, Gray. major, Gray. 



citrinolabris, G. B. Adams. megastoma, G. B. Adams. 



consanguinea, C. B. Adams. microstoma, C. B. Adams. 



dubiosa, G. B. Adams. minima, D'Orb. 



Gossei, Pfeiff. palliata, C. B. Adams. 



hirsuta, G. B. Adams. pusilla, C. B. Adams. 



hispida, Pfeiff. rubella, Pfeiff. 



Hollandi, C. B. Adams. solitaria, C. B. Adams. 



macilenta, G. B. Adams. succinea, Pfeiff. 



Genus LUCIDELLA, Swainson. 



Operculum membranaceous, semi-oval ; columellar margin 

 slightly thickened. 



Shell depressly heliciform, striated, whorls rounded, a 

 little callous at the base ; aperture sinuato-triangular ; 

 peristome thick, furnished with strong teeth. 



Ex. L. aureola, Ferussac, pi. 87, fig. 8. Operculum, 

 L. aureola, fig. 8, a, 8, b. Shell, L. aureola, fig. 8, c. 



The occurrence of three or four teeth on the thickened 

 peristome renders the Lucidella; peculiar among operculated 

 land shells ; one species only is known, from the West 

 Indies. 



