ADAMSIELLA. 297 



Sub-gen. ltcina, Browne. 



Shell conical, the last whorl produced out of the spiral line, 

 straight ; peristome sub-rerlexed, expanded. 



evolutum, Reeve. lincina, Born. 



labeo, Mull. Reeviauum, Pfeiff. 



Sub-gen. jamaicia, C. B. Adams. 



Operculum externally convex, whorls few, rather rugose, 

 obliquely striated, sub-lamellar. 



Shell umbilicated, globose-conical; aperture circular; peri- 

 stome simple, straight, or reflexed. 



anomalum. C. B. Adams. Moussonianum, C. B. Adams. 



Genus ADAMSIELLA, Pfeiffer. 



Operculum circular, thin, sub- cartilaginous, whorls few, 

 gradually-enlarging, with the margins somewhat free; nucleus 

 central. 



Shell pupiform or oblong-turreted ; aperture rather small, 

 sub-circular; peristome generally double, more or less ex- 

 panded or reflexed. 



Ex. A. mirabilis, Wood, pi. 80, fig. 13. Operculum, 

 A. Gray ana, Pfeiffer, fig. 13, a, 13, b. 



With the exception of a single species from Demerara, 

 this group is confined entirely to the Island of Jamaica. 



