126 THE AMERICAN CHARACIDAE. 
rise at the bridge between the fontanels at an angle of about 45° from the line 
joining tip of snout and middle of caudal. Interorbital convex, snout very 
short, mouth very oblique; second suborbital leaving a moderate naked area 
around its entire free margin; maxillary equals snout and eye in front of pupil; 
normally four teeth in the front row of the premaxillary, the third slightly 
removed from the line of the rest; five teeth in the inner series; maxillary 
with one broad or two narrow teeth; mandible with four or five large, graduate 
teeth and several smaller ones on the side. 
Gill-rakers about 10 + 15, slender, the longest nearly half the length of 
the eye. 
Seales cycloid, regularly imbricate, mid-preventral series very small; 
occipital process bordered by about five scales on each side; caudal lobes 
sealed to near their tips; scales of the sides continued without break into the anal 
sheath, which is composed of three or four series of scales in front and reaches 
up one third of the anal base. Scales everywhere cycloid, with several (five 
to seven on a scale above the middle of the lateral line) diverging striae; an 
axillary scale. Lateral line very little decurved, parallel with the row of scales 
just below it. 
Origin of dorsal equidistant from tip of snout and base of upper caudal rays; 
its margin very oblique, the highest ray three in the length; adipose well devel- 
oped, its origin about over the sixth anal ray from the last; origin of anal equi- 
distant from tip of snout, and the third scale behind the dorsal, in the young, 
with the middle of the dorsal in the adult; margin of anal nearly straight; 
ventrals very small, equidistant from tip of snout and base of one of the last 
few anal rays, a little nearer to the tip of the snout than the dorsal or equi- 
distant with the latter, not quite reaching anal in the adult; pectorals long, 
their bases elevated, their tips reaching the third scale above and third or fifth 
behind the origin of the ventrals. 
Color similar to that of Tetragonopterus argenteus, a dark humeral bar 
followed by a lighter area and this again by a bar less well marked than the 
first; the first humeral bar is most intense above the third, fourth, and fifth 
scales of the lateral line, is vertical and extends in some cases to just behind the 
axil of the pectoral; the second bar extends across the ninth, tenth, and eleventh 
scales of the lateral line from in front of the dorsal; the area between the bars 
just above the lateral line is bright silvery. Lower sides brassy; fins hyaline 
to uniform dusky. 
Males with hooklets on the anal. 
