Chestnut Cowrie

The top of the shell displays a large irregularly shaped caramel colored spot, with a dark brown border. The rest of the shell is white, including the bottom. There is a narrow aperture with small teeth that spans the length of the underside of the shell. The shell can grow until the cowrie reaches its adult form, then it stops. When undisturbed, their orange spotted mantle extends around the outside of the shell; when fully extended it can completely cover the shell. The shell is glossy due to an enamel that is secreted from the edges of the mantle. Retracting and extending the mantle acts as a buffer, shining the shell while depositing new enamel. The foot of this species is white. The adult shell of this species ranges in size from 40 to 65 mm.

The chestnut cowrie is the only species of cowrie in the eastern Pacific Ocean. It can be found in intertidal zones from Monterey, California to Isla Cedros, Baja California. It is common in Southern California, specifically around the Channel Islands. Chestnut cowries are rare in the portion of their range that is north of Santa Barbara, California. Chestnut cowries live in kelp beds and rocky surfaces in intertidal and subtidal zones, to a depth of 45 m. Chestnut cowries are often found under rocks and protected crevices.

The chestnut cowrie is a scavenger and carnivore; common food items include anemones, sponges, tunicates, eggs, and dead organisms. This species appears to be an opportunistic feeder that consumes a wide variety of organic matter, including plants and detritus.