308 



IIELICINIDjE. 



Genus STOASTOMA, C. B. Adams. 



Operculum non-spiral, calcareous, finely and irregularly 

 lamelliferous, externally deeply concave. 



Shell globose-conic, depressed or discoidal ; aperture 

 semi-oval, or somewhat semi-circular, angulated above and 

 at the base; peristome continuous, right margin rotundate, 

 produced, regularly curved, the left rather straight, retro- 

 mitting a spiral callus at the base. 



Ex. S. pisum, C. B. Adams, pi. 87, fig. 9. Operculum, 

 S. pisum, fig. 9, a, 9, b, 9, c. 



All the species of Stoastoma proper are sculptured with 

 spiral lines, and inhabit the Island of Jamaica. The sub- 

 genus Electrina is smooth, and is from the Island of 

 Opara. 



Species of Stoastoma. 



Agassizianum, G. B. Adams. 

 Anthoniauum, C. B. Adams. 

 Blandianum, G. B. Adams. 

 Chittyanum, G. B. Adams. 

 Cumingianurn, G. B. Adams. 

 Fadyenianum, G. B. Adams. 

 Gouldianurn, C. B. Adams. 

 Hollandianum, G. B. Adams. 

 Jayanum, C. B. Adams. 

 Leanum, C. B. Adams. 



Lindleyanum, C. B. Adams. 

 Moricandianum, G. B. 



Adams. 

 Petitianurn, G. B. Adams. 

 Pfeifferianum, G. B. Adams. 

 Philippianum, C. B. Adams. 

 pisum, C. B. Adams. 

 Kedfieldianum, C. B.Adams. 

 Tappanianum, C. B. Adams. 

 Vilkinsonise, G. B. Adams. 



Sub-geu. electrina, Gray. 



Shell smooth. 



succineum, Sow. 



