198 THE AMERICAN CHARACIDAE. 
Head 3.25-3.33; depth 2.5-2.7; D.11; A. 17-20; scales 6-33 or 344; 
eye 2.5 in the head, snout about 2 in the eye, interorbital almost equal the eye, 
2.76 in head. 
Compressed; depth of head at base of occipital process 1.5 in the great- 
est depth. Preventral region rounded, without complete, regular series of 
median scales. Predorsal region rounded, with complete series of 10 median 
scales. 
Occipital process about 8 in the distance from its base to the dorsal, bor- 
dered by 2 or 3 scales. Interorbital slightly more convex than in any other 
species of the genus. Frontal fontanel small, triangular, narrower than the 
parietal and two thirds the parietal without the occipital groove. Second 
suborbital leaving a narrow naked margin behind but not below. Snout short, 
mouth large. Maxillary equal to the eye; mandible scarcely longer than 
the eye, about 2.3 in head. Premaxillary with three or four narrow tricuspid 
teeth in the outer row, and five or six tricuspid teeth in the inner row. Max- 
illary with five to seven conical or very narrow 3-pointed teeth. Dentary with 
a series of four or sometimes five tricuspid teeth followed by a graduated series 
of seven to ten minute conical and 3-pointed teeth on the sides. 
Gill-rakers about 6 + 10. 
Anal sheath of 4 to 7 scales covering the bases of the first 7 rays. Pores 
developed on 7 to 10 scales. 
Origin of the dorsal equidistant from the caudal and snout, penultimate 
ray one third the longest which is 3-3.25 in the length. Origin of anal on the 
vertical from the last dorsal ray. Anal very slightly emarginate, third ray 
not reaching to the base of the last ray, the longest ray 1.33 in the length of 
the base, anal armature well developed. Caudal equal to the head. Ventrals 
weak, on the vertical from the first scale in front of the dorsal or from the first 
dorsal ray; ventrals barely reaching the anal. Pectorals just reaching the 
ventrals, distinctly longer than ventrals. . 
Humeral spot very faint, vertically elongate, very near the head. Lat- 
eral stripe narrow and very indistinct. Caudal spot intensely black, covering 
the ventral two thirds of the caudal peduncle, a little narrower in front than 
on the vertical from the origin of the lower caudal lobe, not extending onto the 
caudal rays. The black is on the skin without the scales and also in the scales. 
Top of head and dorsal scales very dark. Scales of upper half of the sides 
heavily outlined with dusky. All fin-webs dusky. Numerous chromato- 
phores scattered over the rest of the body, especially large and prominent on 
