California Frog Shell, Crossata californica

California Frog Shell, Crossata californica. Size: 12.5 cm (5.0 inches) x 7.7 cm (3.0 inches). Shell collected off the beach in San Diego, San Diego, California, July 2015. Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

The California Frog, Crossata californica (Hinds, 1843), is a gastropod mollusk that is a member of the Bursidae Family of Frogs. The shell is robust and appear somewhat flattened because of their width. They have a body whorl marked with knobs, a short spire, thick and knobby varices, deep anterior and posterior canals, and an aperture with flared inner and outer lips that is longer than the spire. The exterior of the shell is cream to tan in color with some southern specimens being encircles by a brown band; the interior is white. More southerly specimens tend to be smaller in size and have sharper sculpture. The California Frog Shells reach a maximum of 16.0 cm (6.3 inches) in length and 9.9 cm (3.9 inches) in height..

California Frog Shells are found on gravel, mud or sand substrate between rocks at depths between 10 m (33 feet) and 180 m (585 feet). They range from Central California to the West Coast of Central Mainland Mexico and they are found in the southern half of the Sea of Cortez.

Synonyms include Bursa californica, Bursa californica sonorana, Bursa sonorana, and Ranella californica.