97 



tinct ; aperture circular, peritreme rather thickened, sihuated 

 at the upper part, and rather angular, forming a very short 

 inconspicuous canal, edge rather obtuse ; umbilicus large, 

 deeply grooved within, its edge with two prominent keels. 



A very rare East Indian species. 



17. C. CLATHRATULA. (pi. xxiii. f. 15. 16.) Recluz. 

 Rev. Zool. 1843. 



T. subglobosa, crassiuscula, spira subconoidali, apice 

 obtuso ; anfractibus 4 — 5, rotundatis, superne spiraliter 

 tenuiter striatis, et decussatis, infra laevibus ; apertura subovali, 

 superne angulata, peritremate crassiusculo, supra umbilicum 

 mediocre, paululum extenso. 



Shell nearly globose, thickish, light yellow brown, with an 

 obtusely pointed, rather conoidal spire, volutions from 4 — 5, 

 rounded, their upper part finely and spirally striated 

 and the interstices of these strife very finely striated obliquely, 

 the lower part smooth ; aperture rather oval, angular above, 

 peritreme thickened, spreading over a very small part of the 

 middling sized umbilicus. From Yemen, Arabia. 



18. C. POLiTUM. (pi. xxiii. f. 17.) nob. 



T. subglobosa, crassiuscula, subpellucida, polita, spira subco- 

 noidali, apice obtuso ; anfractibus 4, rotundatis, pallidis, 

 brunneo-variegatis ; sutura distincta ; apertura circulari, peri- 

 tremate subincrassato, intus subconstricto, superne suban- 

 gulato ; umbilico parvo. 



Shell nearly globose, thickish, subpellucid, shining, spire 

 rather conoidal, with an obtuse, and generally black, tip ; 

 volutions 4, distinctly rounded, of a pale colour, more or less 

 varied with brown, and having a brown band at the lower 

 part ; suture distinctly marked ; aperture circular, peritreme 

 thickened, angular at the upper edge, with a slight internal 

 constriction near the edge, which is obtuse ; umbilicus small. 



19. C. LuciDUM. (pi. xxiii. f. 20. 21.) Lowe. Trans, of 

 Cambr. Phil. Soc. 1831. t. 6. f. 40. 



T. subglobosa, olivacea, spira conoidea, subacuminata, 

 anfractibus 4 — 5, rotundatis, laevibus ; apertura subporrecta, 

 circulari, coarctata, margine obtuso ; umbilico nuUo ; operculo 

 crasso, intiis margine elevato. 



Shell subglobose, olivaceous ; spire conoidal, rather acu- 

 minated ; volutions from four to five, rounded, smooth ; 

 aperture circular, contracted, edge obtuse ; umbilicus none ; 

 operculum thick, with the inner edge raised, Madeira. 



