This large, 300 mm, chiton is commonly referred to as the Gumboot Chiton.
The pure white valves are completely covered by what appears to be coarse maroon leather. The large white valves are often found on the beach and are callled butterfly shells. A commensal polynoid worm, Arctonoe vittata Grube, and a pea crab, Opisssthopus transversus Rathburn, are found living with this chiton. The foot of the Gumboot Chiton is sometimes eaten in the same manner as the abalone.
Younger specimens are colored red and juvenile (25 mm) specimens are yellow.Illustrated whole specimen from the Kay Gudnason Collection. Rearticulated (plates) specimen from the Burghardt Collection. Juvenile specimen photograph from Allyn G.Smith, California Academy of Sciences