The smallest of the black top snails with a squat shell and blunt spire. It has a very distinctive convex base with a large aperture. The background colour of the shell is cream to green overlaid with long irregular zigzags of reddish or purplish brown. The interior is pearly white.

Frequently encountered on exposed southern or west coast shores. Found at the base of large boulders or in rock pools.

It feeds on the microalagal films wich cover the surfaces of rocks and on seaweed.

NZ Coastal Marine Invertebrates; Vol 1