Shell of moderate size to relatively large, up to 70.5 mm. (2,75 inches) in length, solid, narrowly ovate, depressed to moderately elevated, with the apex varying between the anterior fifth and seventh. Sculpture developing from scarcely raised radial folds in juveniles to from 20 to 24 narrowly rounded, sharply raised ribs in the adult. Colour of exterior greenish-grey, the radials marked out in light-brown to reddish-brown, plus a dense overall pattern, in these same colours, in the form of interstitial meandering radial lines and streaks; interior metallic dull blue-grey, with reddish-brown external pattern showing through; spatula buff to pale brown. Length: 42-70 mm; Width: 32-58 mm. ; Height: 12-28 mm.

This subspecies is easily recognised by its dense pattern of interstitial brown lines and streaks on a greenish grey ground. Occasionally the subspecies chathamensis has a similar pattern in juvenile shells, but it never persists into the adult stage, as it does invariably in bollonsi.

Antipodes Islands, southern New Zealand.