(Original description by
J.E. Gray) The size of an adult shell varies between 60 mm and 175 mm. The elongate shell has a conical shape longer than the
aperture. The
whorls are convex. The two or three upper whorls have a strong central keel. The rest show irregularly placed distant rounder tubercles. The
body whorl is rounded, not keeled. The inside of the aperture is white. The erect egg-cases are ovate-oblong, on an expanded base and contracted beneath. The granular surface is deeply punctated. The white, opaque, outer coat of the shell is very much inclined to separate from the inner or central coat, which presents, where the outer coat is removed, a smooth surface of yellowish or brown colour. ==Distribution==