Palmate False Limpet Shell, Siphonaria palmata

Palmate False Limpet Shell, Siphonaria palmata. Shell collected off the beach in the greater Los Cabos area, Baja California Sur, August 2010. Size: 2.5 cm (1.0 inch) x 1.8 cm (0.7 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

The Palmate False Limpet, Siphonaria palmata (Carpenter, 1857), is a gastropod mollusk that is a member of the Siphonariidae Family of False Limpets. The shell is oval in outline, narrowing toward the anterior, with a very low profile, with a flattened apex. The exterior is sculpted with strong radial ribs and the margin is irregular. The exterior of the shell is light to dark brown in color; the interior has varying amounts of dark brown, white, and bluish. Palmate False Limpets reach a maximum of 3.0 cm (1.2 inches) in length and 2.2 cm (0.9 inches) in height.

Palmate False Limpets are found under rocks in the intertidal zone. They are found lower third of the Sea of Cortez, and range south to Peru.