120 



rous close set, spiral ridges ; aperture circular, rather angular 

 at the upper part ; peritreme white, thickened, somewhat 

 reflected, forming a distinct callosity, partly covering the um- 

 bilicus, which is small, with a prominent keel forming its 

 edge and several ridges within. I have a variety with an 

 orange coloured peritreme. 



84. C. unicarinatum. (pi. xxvi. f. 119, 120. Lam. Anim. 

 sans vert. vi. 2. p. 144. Encycl. Meth. t. 461. f. 1. a. b. 



T. globoso-conica, pallida, spiraliter fusco-fasciata, spira 

 acuminata ; anfractibus 4 — 6, rotundatis, lasvibus, medio 

 ultimi carina alba solitaria ; apertura circulari, superne sub- 

 angulata ; peritremate albo, incrassato, revoiuto ; umbilico 

 mediocri, spiraliter sulcato. 



Shell globosely conical, of a pale colour, with dark brown 

 spiral bands, spire acuminated ; volutions from four to six, 

 rounded, smooth, the last having a single white keel ; aperture 

 circular, slightly angular at the upper part ; peritreme white, 

 thickened, revolute ; umbilicus of middling size, spirally 

 grooved. Madegascar. 



85. C. bicarinatum. (pi. xxvi. f. 121.) nob. 



T. globoso-conica, subfusca, spira acuminata, decollata, 

 anfractibus 4 — 6, rotundatis, spiraliter obsolete striatis, carinis 

 duabis albis, altera mediana, altera postica ; apertura circulari; 

 peritremate fulvo, reflexo, patente, callum supra umbilicum 

 mediocre, spiraliter sulcato, efformante. 



Shell globosely conical, of a brownish colour, with an acu- 

 minated decollated spire ; volutions from four to six, rounded, 

 obsoletely spirally striated, with two white keels, the one 

 central, the other above ; aperture circular, peritreme fulvous, 

 reflected, spreading, not revolute, forming a callosity over the 

 middle-sized umbilicus, which is spirally striated within. 



Distinguished from the last not only by its having two 

 keels, but also by its peritreme being spreading and not 

 revolute. Madegascar. 



86. C. tricarinatum. (pi. xxvi. f. 122.) Lam. Anim. 

 sans. vert. vi. 2. p. 144. Chemn. xi. f. 1103, 1104. 



T. globoso-conica, pallide fulva, spira acuminatiuscula ; 

 anfractibus 4 — 6, ventricosis, marginibus superioribus, sub- 

 undulatis, carinis duabis ad quatuor acutis ; apertura circulari, 

 peritremate reflexo, superne acuminato ; umbilico magno, 

 intus carinato, margine carina supereminente. 



Shell globosely conical, of a pale fulvous colour, with a 



