92 



rather prominent, its apex rather ohtuse ; volutions 

 4 to 5, rounded, spirally striated on the upper side, hut 

 smooth beneath ; suture distinct ; aperture circular, slightly 

 acuminated at the upper part ; peritreme thin, with a sharp 

 edge, very slightly reflected ; umbilicus large ; operculum 

 with a deep spiral groove outside, having from 4 to 5 volu- 

 tions. From G. Humphrey's collection, labelled " Poonah." 



4. C. Brasiliense, (pi. xxiii. f. 7-) nob. 



T. orbiculato-subdepressa, tenui, alba, opaca; anfractibus 

 4 — 5, rotundatis, transversim striatis ; sutura profundiuscula ; 

 apertura circulari, peritremate tenui, acuto ; umbilico 

 magno ; operculo testaceo, duplicato, extus tenuissime spirali. 



Shell of a rather depressed orbicular form, thin, white, opaque 

 and chalky in ap})earance, volutions 4 to 5, transversely 

 striated, strife sharp and close set ; suture deep ; aperture 

 circular ; peritreme thin, sharp-edged ; umbilicus large, 

 operculum shelly, thick, double, smooth within, with a very 

 fine spiral line on the outside. Collected in abundance in 

 shady places near Rio Janeiro. 



5. C. giganteum. (pi. xxiii. f. 8, 9.) Gray, Mus. Brit. 

 T. orbiculato-subdepressa, crassiuscula, albicante, epider- 



mide cornea fulva. induta ; apice rufescente ; anfractibus 5 — 6, 

 rotundatis, transversim striatis, striis superne validioribus ; 

 sutura distincta, stria longitudinaliter impressa, prope 

 suturam ; apertura subeffusa, superne angulata, et in ca- 

 nalem inconspicuam subdecurrente, peritremate subin- 

 crassato ; umbilico magno ; operculo linea elevata, spirali, 

 instertitiis oblique striatis. 



Shell of a rather depressed orbicular form, thickish, white, 

 with a red apex, and covered with a horny fulvous epidermis, 

 which is sometimes paler above and darker on the lower 

 part, and sometimes worn away in such a manner as to leave 

 a dark fulvous band in the middle of the last volution ; volu- 

 tions 5 — 6, rounded, transversely striated, more strongly 

 on the upper than on the lower half; suture distinct, 

 with a longitudinally impressed fine near to it; aperture 

 rather spreading, angular above, where it forms an incon- 

 spicuous pointed canal; peritreme rather thickened, not 

 very sharp-edged ; umbilicus large ; operculum with an 

 elevated spiral line, of many volutions, with the interstices 

 obliquely striated. Salango, W. Columbia ; under dead leaves. 



H. Cuming. 



6. C. lNCA.(pl. xxiv.f. 71, 72.) D'Orb. Mag. de Zool. 1835, 

 p. 29. 



