108 



simplici ; apertura elliptica, superne subacuminata; peritre- 

 mate tenui, minime reflexo ; umbilico minimo. 



Shell oblong, somewhat pyramidal, decollated, pale 

 brown ; volutions 4, spirally striated, the interstices of the 

 striee decussated ; suture entire (not crenulated) ; aperture 

 elliptical, rather acuminated at the upper part ; peritreme 

 thin, not reflected ; umbilicus very small. 



51. C. succineum. (pi. xxiii. f. 18, 19.) Zool. Proc. 

 Feb. 18.32. 



T. parva, orbiculato-pyramidali, leevi, succinea; anfrac- 

 tibus quinque, rotundatis ; sutura distincta ; apertura 

 rotundata, peritremate tenui, acuto, margine basali interno 

 angulato ; umbilico parvo, margine carinato. 



A small orbicular shell, having a rather pyramidal 

 form, smooth and of a reddish amber colour ; volutions five, 

 rounded ; with a distinct and strongly impressed suture ; 

 aperture rounded ; having a prominent angle at the lower in- 

 ternal margin ; peritreme thin, sharp-edged : umbilicus small, 

 its margin having a strong spiral ridge. Opara, Mr. Cuming. 



52. C. fasciatum. (pi. xxiv. f. 65.) Lam. 



T. cylindraceo-turgida, apice decollato ; anfractibus 6, 

 laevibus, fascia spirali fusca centrali ; sutura crenulata ; apertura 

 fere circulari. 



Shell nearly cylindrical, somewhat swelled near the middle, 

 with the apex deeply truncated ; volutions six, with a fuscous 

 spiral band on the two central ones ; suture crenulated ; 

 aperture nearly circular. It seems a doubtful Cyclostoma. 



53. C. flavulum. (pi. xxiv. f. 66,67-) Lam. 



T. cylindraceo-attenuata, apice obtuso, paululum decollato ; 

 anfractibus sex, planulatis, laevibus ; sutura distincta, integra ; 

 apertura fere circulari, superne subangulata ; peritremate 

 obtuso, extus producto. 



Shell nearly cylindrical, somewhat attenuated towards the 

 apex, which is blunt and decollated ; volutions six, smooth, 

 nearly flat-sided ; suture distinct, entire ; aperture nearly 

 c ircular, rather angular at the upper part ; peritreme obtusely 

 edged, its external lower part produced. 



54. C. Cumingii. (pi. xxiv. f. 68, 69.) nob. 



T. orbiculari, subdepressa, albicante, epidermide fsca ; 

 spira elevatiuscula, carnea ; anfractibus 5 — 6, rotundatis, 

 spiraliter sulcatis ; sutura subdecurrente ; apertura fere cir- 

 culari, obliqua, alba, superne subacuminata, peritremate sim- 

 plici, subincrassato ; umbilico maximo ; operculo corneo 

 tenui, spirali, anfractibus plurimis, margine fimbriato. 



