CRASPEDOPOMA. 283 



cular groove, the outer edge larger than the aperture, and 

 reflexed over the peristome of the shell. 



Shell turbinate, depressed or sub-discoidal, the last whorl 

 anteriorly detached; peristome free, straight, continuous, 

 received into the circular groove of the operculum. 



Ex. A. cornu-venatorium, Sowerby, pi. 85, fig. 8. 

 Operculum, A. cornu-venatorium, fig. 8, a, 8, b. 



The few species known are from the Island of Ceylon. 



Species of Aulopoma. 



cornu-venatorium, Sow. Itierii, Guer. 



helicinum, Chem. 



Genus CRASPEDOPOMA, Pfeiffer. 



Operculum horny, solid, whorls very narrow, nucleus 

 central, outer lamina flat, inner concave and furnished with 

 a circular marginal prominence. 



Shell sub-turbinate, rimate, axis imperforate, last whorl 

 slightly produced, straight; aperture circular, rather con- 

 tracted ; peristome continuous, simple, receiving the external 

 prominence of the operculum. 



Syn. Bolania, Gray. Hygrobium, Lowe. 



Ex. C. lucidum, Lowe, pi. 85, fig. 9. Operculum, C. 

 lucidum, fig. 9, a, 9, b, 9, c. 



The few species at present known are from the Island of 

 Madeira. 



Species of Craspedopoma. 



costatum, Shuttl. Lyonuetianum, Lowe. 



lucidum, Lowe. 



