Redescription of Dynoides elegans (Boone, 1923) (Crustacea, Isopoda, Sphaeromatidae) from the north-eastern Pacific.

Dynoides elegans (Boone, 1923) from southern California is reviewed, redescribed, and figured. The original species description did not include figures, making it difficult to attribute individuals to the species. Dynoides saldanai Carvacho and Haasmann, 1984 and Dynoides crenulatus Carvacho & Haasman, 1984 from the Pacific Coast of Mexico and Dynoides brevicornis Kussakin & Malyutina, 1987, from Furugelm Island, Peter the Great Gulf in the Sea of Japan, appear morphologically more similar to each other than to western Pacific species. A large pleonal process is present in about half of the Dynoides species, but is absent in this north-eastern Pacific clade and the north-western Pacific Dynoides brevicornis and Dynoides brevispina . Dynoides dentisinus Shen, 1929 possess a large pleonal spine. It is known from China, Japan, and Korea and is introduced in San Francisco Bay; it can be easily distinguished from Dynoides elegans by the presence of a pleonal process in the former. A key to the Pacific West Coast Dynoides is provided.