22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO7 



Description. — Head 29.5 to 33 percent of standard length, its depth 

 28 to 31.5; depth of body 34 to 42; snout 7.0 to 8.5; eye 5.2 to 7.2; 

 maxillary 13.5 to 16; mandible 15 to 18.5; interorbital (bone) 6.5 to 

 7.4 ; caudal peduncle, depth 10.5 to 12.6 ; ventral fin 8.5 to 10 ; pectoral 

 fin 17.5 to 21 ; lower lobe of caudal fin 33 to 37; anal base 17 to 21. 

 Dorsal rays 17 to 20, usually 18 or 19; anal rays 19 to 22; pectoral 

 rays 15 to 17, rarely 13 or 14; scales, oblique series crossing middle of 

 side, 35 to 46, vertical series between tip of pectoral and base of ven- 

 tral o to 3 ; longitudinal series laterally on caudal peduncle 5 ; modified 

 scales in a series on back in front of dorsal fin 32 to 47 ; ventral 

 scutes 29 to 32; vertebrae 45 to 47 (enumerated in 6 specimens). 



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Fig. 4. — Brcvoortia pcctlnata, based on a specimen 290 mm. in total length, 

 223 mm. in standard length (M.C.Z. No. 17636), from Rio Grande, Brazil. 



Body rather strongly compressed, its greatest thickness usually only 

 about a third of its depth, its greatest depth generally a little in ad- 

 vance of origin of dorsal, 2.4 to 2.9 in standard length ; ventral out- 

 line scarcely more strongly convex than the dorsal ; only about half 

 the greatest depth below a straight line extending through the lower 

 margin of eye to middle of base of caudal ; caudal peduncle well com- 

 pressed, its depth 2.6 to 3.1 in head, 3.2 to 3.55 in greatest depth ; head, 

 length 3.0 to 3.4 in standard length, its depth 3.2 to 3.55 ; snout 3.7 

 to 4.4 in head; eye 5.5 to 7.0; maxillary rounded, reaching nearly or 

 quite to vertical from posterior margin of eye, 2.1 to 2.3; interorbital 

 (bone) 4.2 to 4.8; upper section of opercle with rather feeble radiat- 

 ing striae or none ; mandible well included in upper jaw, its length 1.7 

 to 1.85 in head; gill rakers long, very numerous, the longest ones in 

 adults nearly as long as the snout and half the eye, increasing in 

 number with age and growth, about 75 on lower limb of first arch 

 in specimiens 45 mm. long, about 135 in specimens 160 mm. long, 

 and 200 or more in specimens 300 mm. and upward in length ; scales 



