157* 



DESCRIPTIONS OF SOME ADDITIONAL SPECIES OE 

 THE GENUS CYCLOSTOMA. 



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



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

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

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



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

 angulato-flexuosis picta ; spira subdepresso-coiiica, subacuminata ; 

 aiifractibus quatuor, carinatis, pHcis paucis transversaHbus dis- 

 tautibus, ultimo rugis undulatis longitudinalibus sculptis ; sutura 

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

 umbilico mediocri; epidermide crassa, fusca, plicis longitudinali- 

 bus, liis setis fortibus munitis, instructa. 



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

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

 covered with longitudinal folds, which are furnished with strong 

 bristles ; spire rather 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. 



From 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. zebrinum they consist of distant zigzag 

 flames of light chestnut on a wliite ground. 



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

 f. 289), Grai/. 



C. testa globoso-conoidali, albicante, fusco spiraHter hneata et 

 fasciata ; spira subacuminata ; anfractibus rotundatis, Isevibus, 

 ultimo ventricoso, subcarinato, carina alba ; apertura circulari, 

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

 pauso, supra umbdicum subrevoluto ; umbilico majusculo, 

 spiraliter sulcato. 



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



a* 



