The shell is large and solid. The spire is stepped and and can vary. They can be smooth or have spiral grooves on the shell. The shell can be densely covered in dark brown spots on a creamy background. The aperture is yellow and the operculum (door) is horny, thick and dark brown.

Common on mudflats from the mid-intertidal to at least 20m.

An active predator, groups can often be seen feeding on the cockle (Austrovenus stutchburyi).

Females aggregate to lay masses of eggs around the bases of large rocks and rock ledges.

NZ Coastal Marine Invertebrates; Vol 1