21. Tritonidea (s. str.) colensoi, n. sp. Plate XXX, fig. 6.

Shell small, ovate, solid, distinctly broadly spirally lirate, and more or less distinctly axially costate on the spire-whorls. Sculpture consisting of broad and flattish spiral liræ, 3 on the penultimate, 9 to 10 on the body whorl, the interstices narrow, linear; they are crossed on the spire-whorls by flatly rounded axial ribs, about 12 on a whorl, which usually cut up the spirals into squarish nodules. Colour white, the spiral grooves purplish-brown, a few longitudinal narrow light-brown bands passing over the body-whorl and across the interstices of the axial ribs; aperture purple within, outer lip and columella white. Spire short, conic, about the same height as the aperture; outlines faintly convex. Protoconch very small, convex, of 1 ½ smooth whorls. Whorls 5, the last high, flattish; base lightly contracted. Suture not deep, uneven. Aperture somewhat oblique, narrowly channelled above, produced below into a short oblique and narrowly open canal, its base notched. Outer lip very thick, with a blunt edge and a broad varix on the outside; inside callous, denticulate-lirate. Columella vertical, lightly concave, with several ridges at its base; inner lip narrow, not distinctly bounded, extending over the concave parietal wall, which has one or two tubercular plaits above; at the base the lip is narrowed towards the canal. Operculum unknown.

Diameter, 10 mm.; height, 18 mm.

Type in the Dominion Museum, Wellington.

Hab.—East Cape Lighthouse.