348 MEMOIRS OF THE CARNEGIE MUSEUM 



Cotypes, three specimens, 25 to about 38 mm. Tumatumari. (C. M. Cat. 

 No. 1069; I. IT. Cat, No. 11754.) 



Head 4; depth 4.33; D. 10; A. 11; scales 6-36-2.5; eye 2.6; interorbital 3.5. 



Elongate, heaviest above middle of pectoral, the width about one-half the 

 depth; preventral area broadly rounded, postventral rounded; predorsal area broad, 

 with an obscure keel; a median series of about ten scales. 



Occipital process very short, about one-seventh of the distance of its base from 

 the dorsal; skull smooth, but slightly convex; frontal fontanel triangular, nearly 

 as long as the parietal; mouth rounded, projecting beyond the lower jaw; cheeks 

 long and low, the second suborbital about twice as long as broad, its convex margin 

 leaving a considerable naked area, except at a point of contact with the lower limb 

 of the operculum. 



Maxillary-premaxillary border forming a simple, concave curve; horizontal 

 extent of the premaxillary about equal to the length of the maxillary, which is 

 equal to half the length of the eye. Nine teeth in each premaxillary, those in the 

 maxillary similar and continuous with the last of the premaxillary teeth; outer 

 teeth of the premaxillary conical, inner tricuspid; about seven tricuspid teeth in 

 the dentary, of which the first three are large, the rest minute; tips of all the teeth, 

 except those of the maxillary and those of the sides of the lower jaw, brown. Lower 

 jaw short, less than length of eye. 



Gill-rakers 4 + 10. 



Scales very thin; anal sheath none; caudal lobes naked, except for a few large 

 scales on the lower lobe; axillary scale well-developed. 



Origin of dorsal in advance of the middle ; origin of ventrals scarcely in advance 

 of that of the dorsal ; origin of anal behind the last ray of the dorsal; adipose slightly 

 behind base of last anal ray; ventrals not reaching anal; pectorals not nearly to 

 ventrals. 



Straw-colored, with a bright silvery band; first suborbital, cheeks and opercle 

 behind eye, snout, and upper part of head dotted. A continuous curved band 

 crossing third and fourth scale of the lateral line ; scales of the back margined with 

 one to several series of dots; silvery lateral band underlaid with a dotted stripe ; 

 a small caudal spot. 



Bryconamericus Eigenmann. 



Bryconamericus Eigenmann, Ann. Carnegie Mus., IV, 1907, 139 (exodon). 



Type, Bryconamericus exodon Eigenmann. 



This genus is an Astyanax with the front rows of teeth of the premaxillary 

 usually in a wavy line, not parallel with the line of the second row, which is com- 



