32 Annals of the Carnegie Museum. 



at the base of the middle rays ; a pair of rows of dots from the anus 

 along the sides of the anal, a single series of dots behind the anal. 



Genus Bryconamericus Eigenmann. 

 Bryconamericus hyphesson sp. nov. 



Type, 37.5 mm. (No. 1070 Carnegie Museum Catalog of Fishes.) 

 Tumatumari, Lower Potaro. 



Cotypes, 10 specimens, 34-36 mm. Tumatumari. (C. M. Cat. 

 No. 1 07 1, a-b ; I. U. Cat. No. 11 755.) 



Most closely related to stramineus. 



Head 4.5 ; depth 4 ; D. 9 ; A. 16 ; scales 4-36-2 ; eye 2.66-2.75 ; 

 interorbital equals eye. 



Slender, but compressed, greatest depth over tip of pectorals, ven- 

 tral and dorsal outlines equally arched ; preventral area rounded, with 

 normal scales ; postventral area short, compressed ; predorsal area 

 rounded, with a regular series of ten scales. 



Occipital process very short, only about one-eighth of the distance 

 between its base and the dorsal, bordered by two scales on the sides ; 

 s kull convex, smooth, a groove above the eye just within the orbital 

 rim ; frontal fontanel very short, triangular, not half as long as the pari- 

 etal ; snout blunt, the lower jaw included ; mouth small, the maxillary a 

 little more than half the length of the eye ; cheeks not very wide ; 

 entirely covered by the second suborbital ; maxillary with three or four 

 broad, five-pointed teeth ; premaxillary with two series of five-pointed 

 teeth ; four teeth in the inner row, four to six in outer row ; the teeth 

 of the outer row smaller than those of the inner row ; the inner series 

 parallel with the outer except that the third tooth is withdrawn from 

 the line of the rest ; dentary with seven or eight graduated five- 

 pointed incisors. 



Scales very regularly imbricate without interpolated or omitted 

 scales ; about three scales on the base of each caudal lobe ; scales of 

 the sides usually without, those of the tail sometimes with a single 

 line ; anal sheath very narrow, consisting of a single series of minute 

 scales extending along the greater part of the base of the fin ; lateral 

 line decurved. 



Origin of dorsal a little behind the middle of the body, over the 

 middle of the ventrals ; highest dorsal ray 4,} in the length ; adipose 

 fin behind the vertical from the base of the last anal ray; caudal 

 forked, the longest rays a little greater than the depth ; anal slightly 



