154 THE AMERICAN CHARACIDAE. 
Head 4; depth 2.75-3; D.11; A. 22-24; scales 5-32 to 342.5 to 3.5; 
eye 2-2.33 in the head; snout 7.5 in the eye, interorbital very nearly equal to 
the eye, 2.4 to 2.5 in the head. 
Compressed; depth of head at the base of occipital process 1.5 to 1.2 in the 
greatest depth. Preventral region rounded, without complete series of median 
scales. Predorsal region rounded, sometimes with complete series of 9 or 10 
median scales. 
Occipital process 6 in the distance from its base to the dorsal, bordered 
by 3 seales. Interorbital convex. Frontal fontanel narrower than the parie- 
tal, triangular and almost as long as the parietal without the occipital groove. 
Second suborbital in contact with the preopercle. Snout short, mouth moder- 
ately large. Maxillary not quite equal to the eye. Mandible a little longer 
than the eye, 2-2.4 in the head. Preopercle not deeply incised above. Pre- 
maxillary with four or five, 4- to 5-pointed teeth in the inner, and three or four 
tricuspid teeth in the outer row. Maxillary with two or four small uni- bi- 
or tricuspid teeth. Dentary with a graduated series of four, 5- to 7-pointed 
teeth, and several minute conical ones on the sides. 
Gill-rakers 10 + 6. 
Caudal much sealed. Anal sheath of about 5 seales covering the bases 
of the first 6 to 8 anal rays. Lateral line with pores on 9 to 12 sometimes on 
15 scales. 
Origin of the dorsal equidistant from snout and caudal, penultimate ray 
one third of the longest which is 3.5 in the length. Origin of the anal on the 
vertical from the first or second scale behind the dorsal. Anal deeply emarginate, 
longest ray 1.5 to 1.33 in the length of the base. Caudal half the length of 
the eye longer than the head, ventral lobe slightly larger than the dorsal lobe. 
Ventrals on the vertical from the first scale in front of the dorsal, just reaching 
the anal. Pectorals either not quite or just reaching the ventrals. 
No shoulder-spot. A silvery lateral stripe extending from the caudal 
to about the vertical from the first dorsal rays, and continued forward by a 
few large scattered chromatophores. The black caudal spot usually extending 
nearly or entirely to the end of the middle caudal rays. Scales of the back and 
sides outlined with pigment above the lateral stripe, an olive stripe along the 
back, sides above stripe straw colored, scales below the stripe with a light 
blue iridescence. No iridescent spot on the back of the caudal peduncle. All 
fins somewhat dusky. Males with a cherry-red spot on the base of each caudal 
lobe, anterior anal margin with a white bar, broadest towards the tip, the rest 
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