Norris's Kelp Snail

Description:

Norrisia norrisi has a smooth brown shell that ranges in size from a few mm in juveniles up to 59 mm in adults, as measured across the greatest shell dimension. Similar to other trochid snails, such as the more commonly occurring Chlorostoma species (formerly Tegula), the dextrally coiled shell of Norrisia norrisi is also more globose. Other distinctive features include a smooth, green columella, an open, black-ringed umbilicus, and a round aperture sealed with an operculum made of protein rather than calcium carbonate. The fleshy foot of the snail is a bright reddish orange with black speckling lining the basal margin. Four elongate epipodial tentacles are spaced evenly along both sides of the muscular foot. Empty shells of Norrisia norrisi are occupied by hermit crabs, using the hard shell to protect their poorly armored posterior.

Habitat:

The species has been found along the Pacific coast of North America from Monterey to Isla Asuncion on the Baja California peninsula in Mexico. Along the coast of California, with the exception of a persistent population in Diablo Cove, Norrisia norrisi primarily occurs south of Point Conception in the low intertidal and shallow subtidal

Notes:

The marine snail Norrisia norrisi is a medium-sized gastropod mollusk within the family Trochidae. It has several common names, including Norris's top snail, Norris's topsnail, norrissnail, smooth brown turban snail, or kelp snail.