No. 2075. FISHES FROM SOUTHERN CALIFORNIA— GILBERT. 329 



SEBASTOLOBUS ALTIVELIS Gilbert. 



Young individuals, 50 to 100 mm. long, can be distinguished at 

 sight by the coloration. The opercles, gill-membranes, and the 

 abdomen are blackish, the spinous dorsal and the ventrals uniform 

 black, and the pectorals black, often with whitish base and a white 

 margin. Older specimens lose much of this dark coloration, the 

 peritoneum becoming silvery with sparse black specks, and the 

 opercles appearing lighter owing to the thicker integuments masking 

 the dark coloration of the lining membrane of the gill-cavity. The 

 white margin of the pectorals and the light bar at the base widen at 

 the expense of the black, until the latter is confined to a narrow bar 

 on middle of fin, or may even disappear; a narrow black edging to 

 the distal white bar develops secondarily. The terminal half of the 

 outer ventral rays also become white. In adults, the black coloration 

 of spinous dorsal is usually confined to a submarginal streak of nearly 

 uniform intensity throughout, a distinct division into two well- 

 separated blotches never occurring. 



Other characteristics of the species are as follows: 



Spinous dorsal normally XV (XIV to XVI), the fin higher, the out- 

 line angular, the third spine usually distinctly the longest, and much 

 longer than any of the succeeding spines. Notch between dorsals 

 not so deep as in S. alascanus, the last 1 or 2 (only rarely the last 3) 

 spines again lengthened. Gill-rakers a little longer, 7 on upper limb 

 of outer arch, 12 developed and 4 rudimentary on horizontal limb. 

 Cephalic spines lower and more slender, only the posterior paroc- 

 cipital well developed, the anterior either represented by 2 or 3 small 

 points, or wholly undeveloped. 



Spinous dorsal uniformly black (in young) or with a uniform sub- 

 marginal streak, rarely with trace of interruption. Pectorals uni- 

 formly black with lighter base (in very young), or with black confined 

 to a median bar, the base fight, the terminal half light with narrow 

 black margin. The black bar, where present, is uniform, not crossed 

 as in S. alascanus by vertical light lines. The dark coloration of the 

 pectorals may wholly fade in adults. Lining of gill-cavity and pos- 

 terior portion of buccal cavity blackish. 



The nasal cirrus develops as a flat fimbriate tentacle. 



