143 



and fuscous band just below the suture, which is distinct ; 

 aperture nearly circular, with a narrow, reflected peritreme ; 

 umbilicus deep, of moderate extent ; operculum thin, shelly, 

 with a distinct spiral lamina outside. This has been confounded 

 with C. mirabile of Gray, but may very easily be distinguished 

 by attention to the characters of the peritreme. Demerara. 



145. C. thysanorhaphe. (pi. xxviii. f. 162. 163.) nob. 

 T. oblonga, pyramidali, spira acuminata, plerumque decol- 

 late ; anfractibus 3 — 6, rotundatis, transversim striatis, fusco 

 interruptim fasciatis, marginibus superioribus plicato-fimbria- 

 tis ; (suturd crenulatd ; J apertura circulari ; peritremate interno 

 crassiusculo, levatiusculo, externo dilatato-patente ; umbilico 

 parvo ; operculo extiis anfractibus 5 — 6, oblique striatis. 



Shell oblong, pyramidal, with a rather acuminated, but 

 generally decollated spire ; volutions 3 — 6,(3 or 4 when 

 decollated, 5 or 6 when entire,) rounded, transversely striated, 

 of a pale colour, with narrow interrupted fuscous bands, and 

 the upper edges, close to the suture, plicato-fimbriated, the 

 suture itself consequently appearing crenulated : aperture 

 circular ; the internal peritreme thickish, rather elevated, the 

 external one wide, spreading ; umbilicus small ; operculum 

 spiral, consisting of two lamina, the internal smooth and 

 shining, the external with 5 or 6 obliquely striated volutions. 



From Demerara and the Antilles. 



146. C. obesum. (pi. xxxi. f. 278.) nob. 



T. oblonga, crassiuscula, fuscescente, apice decollato, anfrac- 

 tibus 3 — 4, rotundatis, spiraliter sulcatis, tenerrime transversim 

 striatis, apertura subovali, peritremate tenui, reflexo ; umbilico 

 parvo; operculo tenui, anfractibus 3. 



Shell oblong, thickish, of a light brown colour; apex decol- 

 lated ; volutions 3 — 4, rounded, spirally grooved, and very 

 delicately transversely striated ; aperture rather oval, with a 

 thin, reflected peritreme ; umbilicus small ; operculum thin, 

 with only S volutions. Collected by Pfeiffer, in Cuba. 



147. C. pudicum. (pi. xxxi. f. 282.) D,Orb. 



T. ovato-pyramidali, crassiuscula, tenerrime decussata, 

 rufo-fulvescente : apice decollato ; anfractibus 3, rotundatis, 

 peritremate duplici, interno simplici, externo tenui, lato, 

 reflexo, latere columellari emarginato, prope umbilicum 

 incrassato et reflexo, umbilicum claudente. 



Shell ovate pyramidal, thickish, very delicately decussated, 

 reddish fulvous : apex decollated : volutions 3, rounded ; peri- 

 treme double, inner simple, outer thin, broad, reflected, with 



