It may have up to fifteen broad concentric ridges on older specimens.

Circled pearls are characterized by concentric ridges, or rings, around the body of the pearl.

The sculpture on the shell is bold, with both concentric ridges and radiating rays.

It may have several concentric ridges or zones.

The shell is sculptured with about fifteen concentric ridges.

It has a strongly spiralled, smooth shell with concentric ridges that have low relief.

The concentric ridges form a nearly complete ring with the diameter of about 375 km.

Most Pectinidae have radial ribs and concentric ridges, although a few are smooth.

The species typically has broad, concentric ridges, with a blunt and rounded margin.

It has a bulky, oval shell with well defined concentric ridges.