72 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 58. 



bear an oblique calcified spiral lamella on their inner edge, which is 

 obliquely deflected outward. This lamella is always finely obliquely 

 striated, the striations varying considerably in strength in different 

 species. 



Type of the genus. — Turbo lincina Linnaeus. 



ANNULARISCA, new subgenus. 



Shell depressed helicoid, widely umbilicated, marked on spire 

 and base by axial riblets. No trace of spiral sculpture is present, 

 even on the umbilical wall. Operculum typically Annularid. 



Type of the subgenus. — Choanopoma eburneum (Gundlach) Pfeiffer. 



The type species is the only one known of this group at present. 

 It comes from Eastern Cuba. 



ANNULAROSA, new subgenus. 



Shell turbinate, umbilicated. The early whorls with faint axial 

 riblets, which become quite obsolete on the last turn. Umbilicus 

 marked by spiral cords. Operculum typically Annularid. 



Type of the subgenus. — Choanopoma fragile (Gundlach) Pfeiffer. 



The type species is the only one known of this group at present. 

 It comes from eastern Cuba. 



Subgenus ANNULARIA Schumacher. 

 1817. Annularia Schumacher, Nouv. Syst. Hab. Vers Test., pp. 60 and 196. 



Shell ranging in form from turbinate to elongate-conic. Axial 

 sculpture consisting of almost uniform riblets, varying considerably 

 in strength and spacing in different species. Spiral sculpture rang- 

 ing from weak to very strong, covering spire and base, usually more 

 strongly expressed within the umbilicus. Peristome thin, broadly 

 expanded. Operculum typically Annularid. 



Type of the subgenus. — Turbo lincina Linnaeus. 



The following species are now referred to this subgenus. They 

 fall into four groups, as follows : 



Tlie group of Annularia fimhriatulum,: 



Turbo pulchrum Wood Jamaica. 



Cydostoma fimbriatulum Sowerby Jamaica. 



Cyclostoma fimhriatulum, docens C. B. Adams Jamaica. 



Cydostoma fimbriatulum albinodatum C. B. Adams Jamaica . 



Cydostoma chittyi C. B. Adams Jamaica. 



Cydostoma scabriusculum C. B. Adams Jamaica. 



Cydostoma scabriusculum amabile C. B. Adams Jamaica. 



Cydostoma hillianum C. B. Adams Jamaica. 



Cydostoma hillianum amandum C. B. Adams Jamaica. 



Cydostoma hillianum aculeosum C. B. Adams Jamaica. 



Cydostoma hillianum leporilabre C. B. Adams Jamaica. 



Cydostoma wdte C. B. Adams Jamaica. 



Cydostoma lindndlum Lamarck Jamaica. 



