Imperforate, elongated, the spire turrited-conic, the body whorl carinated. Tawny-brown, darker below, fading to a light brown on the spire, the apical whorls a trifle darker; usually in part or almost entirely denuded of the thin creamy-brown hydrophanous cuticle which is disposed in ragged oblique streaks. Spire long, straight-sided, the earlier two whorls forming a somewhat bulbous apex. Whorls 7 to 7,5, the first two convex, the rest flat, the last whorl angular at the periphery, somewhat swollen above and frequently subangular there also. Aperture oblique, broad below, white or livid inside.; peristome dark brown, expanded, receding below; columella long, white, straight, somewhat receding.
Alt. 64, diam. 29; oblique alt. of apert. 31 mill.
Lucban, prov. of Tayabas, Luzon; Albay ; Catanduanes Is., Philippines.
The priority of Lea's name carinatus over that given by Broderip, dactylus, cannot be questioned. I have examined Lea's type, a large and finely developed specimen. In its typical form, C. carinatus is readily distinguished from C. nympha by its larger size and pronounced keel; but intermediate specimens are numerous.
As a varietal genus the name dactylus may stand for the non-carinated, highly variegated examples.