116 



T. orbicularis albicante, castaneo-variegata et fasciata ; 

 spira depressiuscula, apice obtuso ; anfractibus 4 — 5, ventri- 

 cosis, superne spiraliter striatis (striis distantibus, interstitiis 

 obsolete striatis) ultimo maximo, omnibus prope suturam de- 

 pressis ; apertura circulari, peritremate flavicante, simplici, 

 incrassato, reflexo, superne subangulato ; umbilico magno et 

 regione umbilicali albicantibus, spiraliter striatis. 



Shell orbicular, nearly white, varied and banded with chest- 

 nut colour, spire rather depressed, with an obtuse apex : 

 volutions from four to five, ventricose, spirally striated at the 

 upper part, the striee distant, the interstices obsoletely striated, 

 the first volution obliquely striated, the last very large, all de- 

 pressed near the suture : aperture circular, peritreme yellowish, 

 simple, thickened, reflected, slightly angular at the upper 

 part : the large umbilicus and the umbilical region whitish, 

 spirally striated. This is the largest species I know : it 

 varies, however, very much in size, from one inch and a half 

 in width to two inches and a half: the largest specimen was 

 brought from Sumatra by the late Sir T. Stamford Raffles. 

 It is one of several which Lamarck has confounded under the 

 name of C. Volvulus. Java. 



74. C. Petiverianum. (pi. xxv. f. 100, 101.) Gray in 

 Wood's Supp. to Index Testae, t. 6. f. 2. 



T. subglobosa, spira depressiuscula ; anfractibus 5 ven- 

 tricosis, brunneis, mediane fusco-fasciatis, superne suban- 

 gulatis, albido-articulatis ; sutura marginata ; apertura cir- 

 culari, intus alba, peritremate reflexo, brunneo, superne in 

 canalem decurrente ; umbilico magno, margine angulato ; 

 operculo spirali, crasso, corneo. 



Shell subglobose, with a somewhat depressed obtuse spire ; 

 volutions five, ventricose, of a dark brown colour, with a 

 fuscous medial band, their upper edges slightly angular, 

 varied with whitish ; suture distinct, with a raised border ; 

 aperture circular, white within, its peritreme reflected, brown, 

 and its upper edge produced in the form of a pointed canal 

 running upon the latter volution; umbilicus large with an 

 angular margin ; operculum spiral, thick and horny. 



75. C. turbo, (pi. xxv. f. 102, 103) Trochus Turbo, 

 Chemn. ix. p. 53. t. 122, f. 1059. 



T. subglobosa, spira conoidali, anfractibus 5, planulatis 

 pallidis, brunneo-variegatis ; sutura inconspicua; apertura 

 fere circulari, latere columellari subangulato ; columella 

 rectiuscula, sub-obliqua ; peritremate reflexo, rotundato, 



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