Brittle shell up to 2.5 cm in length. It is white, yellow, brown, pink or orange in colour. The surface is sculptured with broad ribs interspersed with finer ones all of which are covered with tubercles. Concentric lines are also present.
- Two types of rib, one smaller than the other, which alternate across the shell surface
- All ribs have one or two rows of tubercles
RareDistributed from northern Norway to the Mediterranean