106 CALIFORNIA ACADEMY OF SCIENCES 



iiiterliperaal); snout 3| in head; maxillary 2|; eye (between eyelids) 3|; interorbital 

 width (between edges of frontal bone) 4; longest (fourth) dorsal spine 2; longest 

 dorsal ray 3|; second anal spine 2|; scales 6 or 7-53-14. Gill-rakers 9+17 on one 

 side, 9+19 on the other. 



For comparison, we subjoin a statement of measurements and counts based on 

 five Panama specimens of flaviguttatvm, each about the same length as the type of 

 opalescens. 



Head 3| to 3| in length; depth 2? to 2' ; dorsal XII, 16; XIII, 16; XII, 

 17; XII, 17; XII, 17; the anal has 3 spines and either 10 or 11 rays; when there 

 are 10 anal rays, the last ray is divided to the base and the two halves are well 

 sei^arated. Snout 3~ to 3| in head; eye (between eyelids) 3| to 4; bony interorbital 

 width 3| to 4; longest (fourth) dorsal spine 2; longest dorsal ray 'd\ to 3|; second 

 anal spine 2f to 2|; scales 6 or 7-51 to 53-13 or 14; gill-rakers usually 10+18 or 

 9+19, in one sjiecimen 11 + 20. 



195. Orthostcechus maculicauda Gill. 



Seldom seen by us. 



Well described and figured by Steindachner (1870 h, p. 12, PI. VI) as Haumdon 

 mazatlnnum. The outline of the spinous dorsal is, however, widely different from 

 that shown in the figure. It is convexly rounded throughout, not concave behind 

 the highest portion of the fin, the second spine exceeds the seventh, and the third 

 is usually slightly longer than the fifth. There is usually a faint indication of the 

 caudal spot. 



196. Anisotremus pacifici (Giinther). 



Rather common in the Panama market. 



The general color is dusky silvery, with four very faint dusky cross-bars, 

 which correspond in position and extent with the more conspicuous bars of A. dovii. 

 The soft dorsal, anal and ventrals are blackish, the caudal and pectorals yellowish. 



The species is characterized by the very short, blunt and wide snout, the 

 narrow preorbital, the very large eye, the short pectoral, and the short dorsal and 

 long anal fins almost devoid of scales. The soft dorsal and anal fins are also rounded 

 in contour, the middle dorsal rays being longer than the anterior rays, and the anal 

 fin not emarginate, as it is in dovii. 



The head is contained 2yV to 3^ times in the length to base of caudal; the 

 depth 2^ to 2|. Eye 4 in head. The preopercular margin is indented above the 

 projecting angle, on which the teeth are moderately or scarcely at all enlarged. 

 Below the angle, the teeth are again reduced and point downward and backward. 

 The normal fin-formula is: dorsal XI, 14; anal III, 10. We find in one specimen 

 only, dorsal XII, 13; and in one other, anal III, 9. The second anal spine is con- 

 tained 1| to 1^, times in the head; the third anal spine 2; to 3J times. The soft 

 dorsal and anal have short series of scales on basal half only of interradial mem- 

 branes, the rays, together with the entire distal half of fins, being naked. In both 



