76 



THE AMERICAN CHARACIDAE. 



Specimens examined. 



Head 3.5-4; depth 2.4 in young, 2 in old; D. 11; A. 27-30; scales 7-33 

 to 34-5. Eye 2.5-2.75 in head; interorbital equals eye. 



Deep, compressed, subrhomboidal, the anal basis straight, nearly parallel 

 with the upper anterior profile in the young, more oblique in the oldest; profile 

 depressed slightly over the eyes and rounded above the occipital process. Pre- 

 ventral area rounded, with a median series of scales, the lateral series not 

 sharply angulated except just in front of the ventrals; predorsal area keeled, 

 with a median series of about 10 scales from the dorsal to the occipital crest. 



Occipital process long, equal to one third of the distance from its base to 

 the dorsal, bordered on the sides by three scales; second suborbital leaving a 

 narrow naked area which is widest below; maxillary not nearly reaching end of 

 first suborbital, but little beyond anterior margin of eye, its length equal to 

 distance from tip of snout to pupil. Four or five teeth in the outer series of 

 the premaxillary; five or six five-pointed, graduated teeth in the inner series; 

 maxillary with one or two minute teeth; lower jaw with four large graduated 

 teeth on each side and many minute ones. 



Gill-rakers about 6 + 14, one third as long as eye. 



Scales deeply imbricate, with several divergent striae; anal sheath of two 

 scales in front; caudal lobes scaled for more than half their length. Lateral 

 fine somewhat descending, parallel with the row of scales below it. 



Origin of dorsal equidistant from tip of snout and base of caudal, its highest 



