Length of largest specimen obtained, 5¼ inches 100. Distance from snout to orbit .06 Length of orbit .03 Snout to end of maxillary process .26 Snout to opercular aperture .27 Snout to first dorsal fin .36 Length of base of dorsal fin .15 Height of dorsal fin .10 From first to second dorsal .03 Length of base of second dorsal .19 Height of second dorsal .10 Length of caudal .16 Width of caudal .12 From caudal to second dorsal and anal .10 Length of base of anal .12 Height of anal .06 From ventral to anal .26 Height of ventral anteriorly .02 Height of ventral posteriorly .08 Height of pectoral .14 Width of base of pectoral .08 Lower jaw to ventrals .27 Width of head between orbits .02 Width of head at opercula .15 Height of head at opercula .16 Width of body at first dorsal .12 Height of body at first dorsal .18 Width of caudal at base .02 Height of caudal at base .09 Distance between ends of maxillary processes .58 _Colors._—When alive mottled with light and dark olive, paler below, sides of head reddish. In alcohol black, pale below, and scales below middle of sides finely punctate each with 8-10 dots, only visible under a microscope. _Hab._—I found these remarkable fish only in San Diego Bay, and in but one station, which was among seaweed growing on small stones at the wharf of Newtown the military post, in November, 1861. They were left by the receding of the tide, and must have been out of the water from three to six hours daily, though kept moist by the seaweed. The four obtained were all females containing large masses of ova, and may have come to the spot in order to deposit them.