159* 



band, the last two pale bands ; aperture circular, dark purplish- 

 black within ; peritreme brownish orange-coloured, rather thick- 

 ened, reflected, slightly spreading posteriorly, and somewhat 

 revolute over the umbilicus, which is small ; operculum externally 

 testaceous, internally horny, of few volutions. 

 Madagascar. Mus. Cuming. 



180. Cyclostoma zonulatum (Tab. Suppl. xxxi. a, f. 296, 

 297), Ferussac, MS. 



C. testa globoso-conica, albicante, fusco-zonulata ; spira levato- 

 conica, acuminata, apice obtusiusculo ; anfractibus quincpie, 

 rotundatis, postice carinis quatuor ad quinque tenuibus, antice 

 striis validis instructis ; sutura distincta ; apertura circulari, peri- 

 tremate lato, albo, extus expanso, intus supra umbilicum postice 

 revoluto, antice angustato ; uinbilico parvo, striis nonnullis validis 

 instructo ; operculo testaceo, paucispirali. 



Shell globose-conical, whitish, girdled anteriorly with narrow 

 fuscous zones ; spire elevated, conical, acuminated ; its apex 

 rather obtuse ; volutions five, rounded, posteriorly with from four 

 to five slender keels, and anteriorly with well-marked striae ; 

 suture distinct ; aperture circular ; peritreme white, broad, spread- 

 ing outwards, and posteriorly revolute over the umbilicus on the 

 columellar side ; umbilicus small, spirally grooved within ; oper- 

 culum testaceous, of few volutions, white. 



Mas. Cuming. 



181. Cyclostoma laxatum (Tab. Suppl. xxxi. a, f. 302), 



nobis. 



C. testa orbiculari-deprcssa, albida, epidermide aurantiaco- 

 brunnea induta ; spira depressa, apice rufescente ; anfractibus 

 quatuor, rotundatis, rugulosis, ultimo zonis duabus, altera albida, 

 altera fusca, striis incrementi validis; apertura subdepresso-cir- 

 culari, postice prope ultimum anfractum paulisper angulata ; 

 peritremate tenui, antice paululum reflexo ; umbilico maximo, 

 anfractibus quatuor conspicuis. 



Shell of a depressed orbicular form, whitish, covered with a 

 thick orange-brown epidermis ; spire depressed, with a rufous 

 apex ; volutions four, rounded, covered not only with distinct 

 lines of growth, but also with irregular rugulosities, with two 

 narrow zones, the posterior white, the other fuscous, in front of 

 winch the epidermis is more darkly coloured ; aperture not qiute 

 circular, but very slightly elliptical, and with a slight angle pos 



6* 



