Shell of moderate to large size, up to 73.5 mm. in length, solid, ovate, elevated, and roundly arched in profile, with the apex at about the anterior third. Sculpture consisting of from 21 to 25 moderately strong, rounded, radial ribs, with a weaker one in most interspaces; the whole surface crowded with concentric growth lirations, weak over the early stages of the shell but stronger towards the margin, where they become slightly knotted across the radials. Colour of exterior pale yellowish-brown to greyish lilac, the radials lined in reddish brown; internally, silvery to yellowish brown, with regular reddish brown radial lines, corresponding to the external ribbing, their terminal points not coalescent at the margin; spatula large, fawn to orange-brown. Juvenile shells pale yellowish to almost black, with the pattern varying from a few radial lines to a dense coverage of meandering lines and streaks. Length: 40-74 mm; Width 30-57 mm; Height: 11-35 mm.

This subspecies resembles redimiculum in its simple radiate reddish brown radials, not coalescent at the margin, but the shape is more roundly arched, and the ocellate pattern is not in evidence. On the other hand some juveniles have a dense meandering pattern, reminiscent of the bollonsi pattern.

Chatham Islands, New Zealand.