224 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



vomer, tongue, and sometimes on palatines; lateral line with a high 

 arch anteriorly, its chord equal to or longer than straight part of line, 

 straight part without definite scutes; scales rudimentary, except on 

 caudal peduncle; second dorsal and anal with prominently produced 

 lobes anteriorly in large specimens. Anterior dorsal spines bearing 

 filaments, and the ventral fins greatly enlarged in young. 

 Only one species is known from Peru. 



SELENE BREVOORXn (Gill) 



Reloj; Cobcovado 



Argyriosus brevoortii Gill, 1863a, p. 83, Baja California (original description, 



based on a young individual). — Walford, 1937, p. 80, pi. 55, fig. b, in color 



(diagnostic characters; habits; size attained). 

 Selene vomer Evermann and Radcliffe (not of Linnaeus), 1917, p. 62, Tumbes 



River, Peru (enumerations and proportions based on a small specimen). 

 Selene brevoortii Meek and Hildebrand, 1925, p. 374, pi. 32, Panama Bay 



(synonymy; description; compared with S. vomer of the Atlantic). 



Head 2.5 to 2.6; depth (at vertical from origin of anal) 1.4 to 1.6; 

 D. VIII-I, 21 or 22; A. II, I, 17 or 18; P. 18 or 19. 



Body everywhere with sharp edges; anterior profile oblique, a little 

 concave over snout, forming an angle in occipital region of about 120°; 

 back, in front of dorsal fin, with three low humps; ventral margin 

 from vent to anal formed of a continuous bony plate, with two sharp 

 points (anal "spines") in young, these scarcely evident in adults; snout 

 1.6 to 1.8 in head; eye 4.4 to 6.0; interorbital 6.4 to 7.0; horizontal 

 distance from eye to margin of profile equal to or less than diameter of 

 eye, and less than half width of space between eye and premaxillary ; 

 mouth quite oblique; mandible projecting; maxillary wider than half 

 diameter of eye in large examples, 3.0 to 3.4 in head; teeth in jaws 

 minute, in a more or less definite band in each jaw, gill rakers slender, 

 denticulate along inner edge, about two-thirds length of eye, 29 to 32 

 on lower and 5 to 9 on upper limb of first arch ; lateral line anteriorly 

 with a high arch, its chord nearly as long as the straight part; scales 

 small, rudimentary, somewhat enlarged and with free edges only on 

 caudal peduncle; first dorsal with two somewhat elevated spines in 

 front, about 1.5 times diameter of eye in adults, these spines bearing, 

 long filaments in young, the other spines low and separate; second 

 dorsal greatly elevated anteriorly in large specimens, the elevated 

 portions in some specimens reaching base of caudal, in others nearly 

 to tip of caudal fin; anal, except for the less produced anterior lobe, 

 similar to second dorsal, its base 2.1 to 2.3 in length; ventral scarcely 

 longer than eye in large examples, very large in young, about as long 

 as head in smallest specimen at hand; pectoral falcate, proportionately 

 longer in large examples than in small ones, 2.3 to 2.6 in length. 



Color bluish to dusky along back, the rest of body bright silvery; 

 anterior margin and produced portion of second dorsal dark; fins 

 otherwise mostly pale to straw yellow. 



