157* 



DESCRIPTIONS OP SOME ADDITIONAL SPECIES OP 

 THE GENUS CYCLOSTOMA. 



Figured in Supplementary Plates XXXI. A. and XXXI. B. 



176. Cyclostoma zebrinum (Tab. Suppl. xxxi. a, f. 287, 

 288), Benson. Cyclostoma zebrinuni, Benson, Journ. of Asiatic 

 Soc. of Calcutta, 1836, vol. v. p. 355. 



C. testa suborbiculari, albida, strigis pluribus rufo -castaneis, 

 aagulato-fiexuosis picta ; spira, subdepresso-conica, subacurninata ; 

 anfractibus quatuor, carinatis, pbcis paucis transversabbus dis- 

 tantibus, ultimo rugis undulatis longitudinabbus sculptis; sutura 

 distincta ; apertura circulari, peritremate incrassato, albo, reflexo ; 

 umbilico mediocri; epidermide crassa, fusca, plicis longitudinab- 

 bus, liis setis fortibus muuitis, instructs, 



A ratlier thin shell, of a pale colour, varied with reddish chest- 

 nut angular streaks and lines, and with a thick fuscous epidermis, 

 covered with longitudinal folds, which are furnished with strong- 

 bristles ; spire ratlier depressed, conical, and somewhat acumi- 

 nated ; volutions four, carinated and irregularly spirally striated, 

 irregular obsolete ridges on the last volution, few, distant ; suture 

 distinct ; aperture circular, with a thickened, white, reflected 

 peritreme ; umbilicus of moderate size. 



India. Benson. 



Prom C. perdix it differs in its sculpture, its more developed 

 keel, more contracted umbilical cavity, and in its possession of a 

 singular epidermis. In C. perdix the marks are white, mottled on 

 a chestnut ground ; in C. zebrinnm they consist of distant zigzag 

 flames of light chestnut on a white ground. 



177. Cyclostoma Madagascariense (Tab. Suppl. xxxi. a, 

 f. 289), Gray. 



C. testa globoso-conoidali, albicante, fusco spiraliter lineata et 

 fasciata ; spira, subacurninata, ; anfractibus rotundatis, laivibus, 

 ultimo ventricoso, subcariuato, carina alba ; apertura circulari, 

 intus castanea ; peritremate pallide aurantiaco, lato, extiis ex- 

 panso, supra umbilicum subrevoluto ; umbilico majuscido, 

 spiraliter sulcato. 



Shell of a conical globose form, whitish, with spiral fuscous 



a* 



