DEC. 28, 1916. FISHES or PANAMA MEEK AND HILDEBRAND. 285 



the Rio Cascajal, a small coastal stream, at Porto Bello, on April 24; 

 nearly all are gravid fish. 



This species differs from the preceding in the smaller scales, in 

 the somewhat darker coloration, principally in the darker lateral band 

 and in that the breeding male has numerous small tubercles on head 

 and margin of scales and very rough fins. 



24. Genus Hemibrycon Giinther. 



Hemibrycon Gunther, Cat. Fish. Brit. Mus., V, 1864, 318 (type Hemi- 

 brycon polyodon Gunther). 



Body elongate, compressed; head short; maxillary extending nearly 

 or quite to middle of eye; cheeks nearly entirely covered by the first 

 and second suborbitals, leaving only a narrow naked margin behind; 

 premaxillary teeth in 2 series, the inner series with 4+4 or 5+5 teeth; 

 maxillary in the adult with from 5 to 25 teeth, these in part at least 

 tricuspid, teeth along half or more of its free margin; lower jaw with from 

 4+4 to 6+6 strong teeth anteriorly and with gradually or abruptly 

 smaller teeth at sides; lateral line complete; scales cycloid; caudal 

 naked; middle caudal rays black. 



Closely related to Bryconamericus, but with more teeth on the 

 maxillary, at least in the adult, and with the inner caudal rays 

 black. 



33. Hemibrycon dariensis sp. nov. 



Type No. 8947, F. M. N. H.; length 65 mm.; Rio Yape, Rio 

 Tuyra Basin, Panama. 



Head 3.45 to 4.5; depth 2.4 to 3.55; D. 9 or 10; A. 27 to 29, rarely 

 30; scales 8-38 to 41-6. 



Body elongate, compressed; profile straight or gently convex over 

 eyes, elevated at nape; head short; snout blunt, 4 to 5 in head; eye 2.6 

 to 3.25; interorbital 2.8 to 3.15; mouth moderate; jaws subequal; maxil- 

 lary reaching nearly to opposite middle of eye; premaxillary teeth in 2 

 series, the outer series irregular, the last tooth on each side and the 

 2 anterior teeth placed further outward, the second series with 8 larger 

 teeth, each tooth with 4 to 5 cusps, one of them considerably enlarged; 

 maxillary with from 6 to 10 teeth, similar to second premaxillary series, 

 but larger, abruptly smaller ones at sides, these about 10 in number; 

 gill-rakers short, 10 on lower limb of first arch; lateral line complete, 

 decurrent, the pores on anterior 3 to 6 scales usually poorly developed; 

 scales thin, striate, 14 to 16 rows in advance of dorsal, 9 to n rows 

 between dorsal and adipose, the longitudinal rows above and in advance 



