218 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



age number of gill rakers, and in being darker in color. However, 

 for the present the specimens from the two localities may be considered 

 as of the same species. 



Range. — Gulf of Cahfornia to Peru. 



Genus SERIOLA Cuvier, 1817 



Amberjacks 



Body elongate, moderately compressed; back only moderately 

 elevated; head rather low, not especially blunt; mouth rather large; 

 premaxillaries protractile; maxillary very broad, with a wide supple- 

 mental bone; teeth very small, in a band in each jaw, present also on 

 vomer, palatines, and usually on tongue; lateral line with a long low 

 arch, with a slight keel, but no bony scutes, on caudal peduncle; first 

 dorsal with six to eight spines, connected by membranes; second dor- 

 sal long, more or less elevated anteriorly; anal similar to second dorsal, 

 but much shorter; ventral generally equal to or shghtly longer than 

 the short pectoral. 



A single species, S. colburni, was secured in Peru by the Mission. 

 A second species, S. peruana, was described from Callao. This second 

 species, which probably is identical with S. mazatlana, has not been 

 taken by recent collectors. The characters used in the following key 

 are in part based on specimens from Panama Bay and the Galdpagos 

 Islands. 



KEY TO THE SPECIES 



a. Gill rakers few, 15 to 17 on lower limb, and only about 4 on upper limb, of 

 first arch; anterior lobes of second dorsal and anal considerably elevated, 



longest ray of dorsal 1.3 to 1.5 in head colburni (p. 218) 



aa. Gill rakers more numerous, 20 to 22 on lower limb, and 6 to 8 on upper limb, 

 of first arch; anterior lobes of second dorsal and anal not greatly elevated, 

 longest ray of dorsal 2.4 to 2.6 in head (longer in very young). 



mazatlana (p. 219) 



SEBIOLA COLBURNI Evermann and Clark 



Seriola colburni Evermann and Clark, 1928, p. 685, pi. 27, oflf Cape San Lucas, 

 Baja California (original description, based on a skin; compared with re- 

 lated species).— Walford, 1937, p. 63, pi. 46, Mexico (diagnosis; size; 

 distribution; habits; angling notes). 



Head 3.3; depth 3.15; D. Vll-I, 29; A. II-I, 21. 



Body fairly compressed, its greatest thickness about half the depth; 

 dorsal profile much more strongly curved than the ventral, with some- 

 what compressed edge in occipital region; head moderately large, 

 compressed, snout fairly long, 2.6 in head; eye 5.7; interorbital 3.2; 

 mouth a Httle obhque, terminal; maxillary reaching nearly to anterior 

 margin of pupil, fan-shaped, with a large supplemental bone, slightly 

 rounded, its width exceeding diameter of eye, 2.4 in head; teeth all 

 very small, in a broad band in each jaw; gill rakers rather stout, 

 shorter than eye, 15 on lower and 4 on upper limb of first arch: lateral 



