A tall, narrow shell crossed by curved, vertical growth lines. It is brownish or green grey and can be eroded. The operculum is horny and circular. Can be confused with Z. subcarinatus but it can be twice as large and is paler in colour.

It is found in the mid tide zone of protected areas including mudflats and tidepools on coralline algae turf and Neptunes necklace flats.

Passes mud through the gut to extract nutrients.

NZ Coastal Marine Invertebrates; Vol 1
Photo Credit: Rod Morris. Photos available from www.rodmorris.co.nz