Calliostoma annulatum

This top shell can be found in the littoral zone from Isla San Geronimo, Baja California, north to Forrester Island, Alaska.

This species is distinguished by its brilliantly colored shell, which is lustrous with a gold field, dotted with brown on the spiral rows of grains, the periphery or lower edge of each whorl encircled by a zone of violet or magenta stripes, the axis surrounded by a tract of the same.

The thin shell shows numerous granulose spiral riblets, about 7 on the penultimate whorl, 9 or 10 on the base.

There are about 9 whorls, slightly convex, the last angular at periphery, flattened beneath.

This species is fairly omnivorous, feeding seasonally on kelp, sessile fauna like bryozoans, and detritus.

Two individuals of Calliostoma annulatum are visible on this hydrocoral