It has a velvety black appearance. This black mantle tissue often covers the small shell, but a gentle touch will cause it to retract the mantle so the shell is seen. The white shell resembles a shield with straight parallel sides, curved posterior end and straight anterior end. Concentric growth lines maybe visible on the shell. To the unknowing often mistaken for a paua who has lost it's shell!

Common under boulders in the mid to low tide zone down to depths of 20 m. More common intertidally in northern NZ and more common subtidally in southern NZ.

it grazes on red and green seaweeds and returns to its home site at low tide. It avoids light and feeds mainly at night.

If threatened it can secrete a noxious fluid from glands on its back to deter predators.

Common Seashells of New Zealand: Parkinson