164 ALLAN HAXCOCK PACIFIC EXPEDITIOXS VOL. 20 



PLATE 5 



Mytella (juyamnsis (Lamarck) 1819. San Felipe, Cnilf of 



California. Length: 61 mm. 



Mytella (/uyanensis (Lamarck) 1819. San Felipe, Gulf of 



California. Enlarged part of the resilial ridge, showing 



the pittings; the ligament is seen on the top. 



Mytella falcata (Orbigny) 1846. Chacahua, Laguna de 



Oaxaca, Mexico. I^ark colored specimen. Length: 35 mm. 



Mytella speciosa (Reeve) 1857. Bahia de la Magdalena, 



Baja California. (San Diego Museum) Length: 51.5 mm. 



