11 



ceding ; aperture ovate-orbicular, well angulated above, white within 

 next the lip, with the fauces yellowish brown ; lips single, slightly 

 spread and reflected into the plane of the aperture, a little alate at 

 the angle ; umbilicus very small. 



Mean divergence 30° ; length .64 inch ; greatest breadth .35 inch ; 

 least breadth .26 inch. 



30. Cyclostoma muticum. Species like C. armatum, but the shell 

 is more slender ; and more delicately striated transversely ; the out- 

 lines of the spire are more convex ; there are no sutural crenulations; 

 the aperture is smaller, less regularly ovate, and more angulated above. 



Mean divergence 28° ; length .57 inch ; greatest breadth .27 inch ; 

 least breadth .23 inch. 



31. Cyclostoma fecundum. Shell much elongated, conic; 

 brownish or reddish brown, sometimes with darker more or less trans- 

 verse clouds, with numerous elegant spiral series of small dark brown 

 spots, which are arranged at unequal distances in transverse lines, and 

 are most conspicuous in the young shell, disappearing with age ; with 

 transverse striae like C. armatum, and spiral faintly impressed lines 

 on the upper whorls ; spire with scarcely convex outlines ; apex trun- 

 cate with the loss of three whorls ; five rather convex whorls remain- 

 ing, with a moderately impressed suture ; aperture large and spread- 

 ing, less oblique than in the two preceding species, ovate, much angu- 

 lated and extended into a sinus above ; lip single, rather thin, a little 

 spreading, scarcely reflected back to the plane of the aperture; umbil- 

 icus small, with rather strong spiral striae. 



Mean divergence 33° ; length .72 inch ; greatest breadth .37 inch ; 

 least breadth .3 inch. 



Var. distinctum, with the aperture a little detached from the last 

 whorl. 



32. Cyclostoma aurora. Shell much elongated, ovate-conic ; 

 very pale orange, sometimes with very faint spiral darker lines, white 

 next the aperture ; with very strong not closely set whitish transverse 

 raised lines, and two or three very faintly impressed spiral striae on the 

 upper part of the whorls ; spire with slightly convex outlines ;4apex 

 truncate with the loss of three whorls ; four and one-half whorls re- 

 maining, moderately convex, with a well impressed suture ; aperture 

 ovate, moderately spreading, appressed a little to the penult whorl 

 below the angle above, which is detached ; lip rather thin, scarcely 

 spreading and but little reflected, umbilicus very small, with strong 

 spiral striae. 



Mean divergence 30°; length .65 inch; greatest breadth .31 inch; 

 least breadth .26 inch. 



Given to me in Jamaica as a native species. 



