CYCLOSTREMA. 99 



C. TUBERCULOSA, d'Oi'b. PI. 35, fig. 65a. 



Narrowly umbilicated, thick, white, with six tuberculated spiral 

 ribs ; whorls 4, convex, the last large ; aperture x'ounded, peristome 

 thick, externally tuberculated. Diam. 2 mill. 



Cuba. 



Section Daronia, A. Adams. 1864. 



C. CYCLOTINA, A. Ad. PI. 33, fig. 16. 



Umbilicus lai'ge, flat within, surface smooth, spire flat, last whorl 

 rapidly increasing, not contiguous, aperture subangular above. 



Diam. 4 mill. Japan. 



C. suBEXCAVATA, Tryon. PI. 33, figs. 17, IS. 



Umbilicus wide, perspective, shallow, whitish under a yellowish 

 brown, membranous epidermis, spire scarcely raised, suture broadly, 

 angularly impressed, a little below the suture there is a bluntly 

 angulated spiral keel, and on the middle of the base, towards the 

 mouth there is another keel; whorls 4, rather slowly increasing, 

 until the last, which is rather large ; mouth a little oblique, peristome 

 simple, thin. Diam. 2'15 mill. 



Off Cidebra IsL, W. Indies; 390 >s. 



Described by Watson as C. excavata, preoccuj^ied by Carpenter. 



C. CATENOIDES, Monts. PI. 34, figs. 20, 21. 



Widely umbilicated, closely spirally striated throughout, with 

 several spiral chain-like lines on the base, whorls convex, regularly 

 increasing. Diam. 1"25 mill. 



Harbor of Civita Vecchia, Italy. 



C. sEMisuLCATA, Issel. PI. 34, fig. 22. 



Widely umbilicated, subpellucid, shining, closely spirally sulcate 

 above, smooth below; whorls 4, rapidly increasing, convex; peris- 

 tome simple, acute, margin interrupted. Diam. 3 mill. 



Red Sea. 



C. OCTOLYRATA, Carpenter. PL 34, figs. 24, 23. 



Widely umbilicated, with eight spiral lirie covering the last whorl; 

 whorls Si, convex, regularly increasing; peristome thin, modified 

 by the lirse. Diam. 1"75 mill. Bed Sea. 



The figure is from a shell identified by Issel with Carpenter's 

 description. 



