296 cyclostominjE. 



truncatum, Wiegm.. Venezuelense, Pfeiff. 



turritum, Pfeiff. vespertiuum, Morel. 



Genus CHOANOPOMA, Pfeiffer. 



Operculum testaceous, sub-circular, with gradually-en- 

 larging whorls, their outer margins free, acute, often elevated 

 into prominent, thin lamella? ; nucleus sub-excentric. 



Shell globosely turbinate or turreted, often truncated, 

 rarely, depressed; aperture sub-oval or circular; peristome 

 usually double, the internal continuous, circular, the external 

 rectangular, expanded. 



Syn. Gastrodonia, Partiot. 



Ex. C. scabriculum, Sowerhy, pi. 86, fig. 12. Oper- 

 culum, C. scabriculum, fig. 12, a, 12, h. Shell, 0. fimbria- 

 tulum, Sowerhy, fig. 12, c. 



A group of beautiful shells, entirely West Indian in their 

 geographical distribution, and principally from the Island of 

 Jamaica. 



Species of Choanopoma. 



Adolf], Pfeiff. mactum, Poey. 



alatum, Pfeiff. mite, Pfeiff. 



Chittyi, C. B. Adams. pisum, C. B. Adams. 



decussation, Lam. Pretrei, D'Orb. 



fimbriatulum, Sow. pudicum, D'Orb. 



grauosum, C. B. Adams. pulcbrum, Wood. 



Hilliauum, C. B. Adams. scabriculum, Sow. 



interruptum, Lam. solutum, Rich. 



lima, C. B. Adams. spinulosum, C. B. Adams. 



lincinellum, C. B. Adams. tentorium, Pfeiff. 



