136 THE AMERICAN CHARACIDAE. 
Minute or small; premaxillary teeth in two rows; the maxillary teeth 
wanting or reduced in number and restricted to the upper part of its free margin; 
scales in the lateral line 29-36; lateral line incomplete. Caudal scaled. 
Hasirat.— Orinoco, Essequibo south to Paraguay, Rio das Velhas, and 
Rio Grande do Sul. 
Key to the Species. 
a. Dorsal with a well-defined black spot. 
b. Anal unmarked, a black line along its base. Dorsal black, with a wide white stripe from the tip 
of the first rays to the base of the last. Humeral spot horizontally elongate, continued as a 
black line to the caudal. Second suborbital leaving a wide naked margin behind and below. 
Maxillary with two or three conical or tricuspid teeth. D. 11, A. 23 to 25; scales 5 or 6-30 to 
DOT OO stasis cline «is Mislote Ae eee ced Eee Se oe aes ne STS ee eee 1. ulreyi (Boulenger). 
bb. Anal with black on the rays. 
ce. An iridescent blue line one scale wide extending from the base of the pectoral to the scale above 
the last anal ray; a wide light lateral stripe from the upper part of the eye to above the 
middle of the base of the caudal, interrupted or not by the vertically elongate humeral spot. 
Ventrals and anal lobe with a submarginal dark band. Second suborbital leaving a narrow 
naked margin. Maxillary with four or five, sometimes two or three, tricuspid teeth. 
D. 11; A. 20'to 22:\ scales'5-3) or 82-8/5.........2.sacrsee-ocoun 2. coeruleus Durbin. 
cc. Anal with an intense black bar from a little in front of the base of the first ray to the tips of 
the fourth and fifth rays. Humeral spot vertically elongate, often faint and sometimes 
lacking. Second suborbital leaving a narrow naked area below. Six small, tricuspid and 
conical teeth in the maxillary. D. 11, A. 23 to 27; scales 5-32 to 34-3 to 4.5. 
3. unilineatus (Gill). 
ccc. Black on the dorsal restricted to the first three rays, usually not intense. An oblique blackish 
line from the base of the third to the tip of the seventh anal rays; tips of the second and 
third rays white. No humeral spot. Second suborbital without naked margins. Maxil- 
lary with three, 5-pointed teeth. D.11; A. 23 or 24; scales 5-30 to 33-4.5. 
4. elegans (Steindachner). 
aa. Dorsal without well-defined black markings (see also elegans). 
d. No humeral or caudal spot. 
e. A wide lateral streak from the middle of the caudal to the head and another narrower 
streak from above the anterior anal rays to the mandible without black chromatophores; 
the sides and back everywhere else dusky. Anal lobe and distal half of dorsal lobe 
dusky. Second suborbital about one half as wide as the eye; without naked margins. 
Maxillary 1.33 in the eye, with two to four, 3- to 5-pointed teeth. D. 11; A. 20 to 22; 
scales 5=31 to 189-3 t08325s hens tusoee eet ee eee oe 5. erythrozonus Durbin. 
ee. Lateral stripe leaden, caudal lobes crossed by a broad, black marginal or submarginal 
band. Maxillary slender, about equal to the eye. D. 11; A. 20 to 24; scales 5-29 to 
SEO VON a enn wayne ae Ntity AL eye: Ger Ee 6. marginatus Ellis. 
dd. No humeral spot, caudal spot usually developed, (see also marginatus). 
f. Maxillary without teeth. 
g. Premaxillary teeth tricuspid or conical. Maxillary much shorter than the eye. D. 
11; A. 17 to 19; scales 3.5-30 to 32-2.5 to 3.............. 7. nanus (Liitken). 
gg. Premaxillary teeth 5- to 7- and 9-pointed. Maxillary equal to the eye. D. 11; 
A.'17it0720;/scales'5=30) to $48.5 8.-cees,c eon ee eee ene 8. levis Durbin. 
ff. Maxillary with teeth. 
h. An unpigmented area between the caudal spot and the lateral stripe; caudal spot 
not continued forward on the caudal peduncle. Premaxillary teeth with 5 to 7 
cusps. Second suborbital two thirds the eye in width. Depth 3.2. Maxil- 
lary with one 7-pointed tooth. D.11; A. 24; scales 4-32-4. 
9. microplerus Meek. 
hh. Caudal spot continued forward on the caudal peduncle; more or less continuous 
with the lateral stripe. 
