The shell is small, globular and smooth. It has a highly polished surface, the colour and pattern is very variable, but is often tesselated in dark grey on a light background. It is small, only 8 mm in height.

Common around boulders or the holdfasts of kelp on semi-exposed to exposed open, rocky coasts. In intertidal areas it is only found in rock pools.

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

previously Cantharidus tesselatus

NZ Coastal Marine Invertebrates; Vol 1