Ground color light yellowish-brown to burnt umber, occasional individuals may be greenish. Small pink and cream dots or dark brown, dull green, and yellow dots may occur on body. Cerata inflated and rather tuberculate, same color as body, with a pale red spot on outer side of each ceras, about one third of the distance from base. Rhinophores irregularly perfoliate.
Typically about 25mm in length, but may exceed 40mm.
Cape Meares, Tillammok Co., OR, to Isla Angel de la Guardia, Baja California, Mexico; Japan.
Preys on arborescent bryozoans.
MACFARLAND, F. M. 1912. The nudibranch family Dironidae. Festschrift zum Sechzigsten Geburtstage des Herrn Geheimen Hofrats Prof. Dr. Johann Wilhelm Spengel in Giessen. Zoologische Jahrbücher Supplement 15(1):515-536, pls. 30-32. PDF
MACFARLAND, F. M. 1966. Studies of opisthobranchiate mollusks of the Pacific coast of North America. Memoirs of the California Academy of Sciences 6:1-546, pls. 1-72. PDF
McDONALD, G. R. 1983. A review of the nudibranchs of the California coast. Malacologia 24(1-2):114-276. PDF
SOUTHERN CALIFORNIA ASSOCIATION OF MARINE INVERTEBRATE TAXONOMISTS. 2018. A taxonomic listing of benthic macro- and megainvertebrates from infaunal & epibenthic monitoring and research programs in the southern California bight, edition 12, 1 July 2018, xviii + 167 pp. PDF