226 THE AMERICAN CHAEACIDAE. 



Occipital process about 6 in the distance from its base to the dorsal, bordered 

 by 3 or 4 scales on the side. Interorbital convex. Frontal fontanel half as 

 long as the parietal and occipital process. Head pointed, its upper and lower 

 profiles about equally divergent from the mouth. Second suborbital short 

 and deep, leaving a narrow naked margin behind and a broader one below. 

 Mouth large, terminal. Maxillary extending to the end of the preorbital, 2.5 

 in the head. Maxillary-premaxillary border without a distinct angle. Three 

 small tricuspid teeth in the outer series of the premaxillary ; five narrow tri- 

 cuspid teeth in the second row, the middle one the longest, graduated slightly 

 to the last, which is about twice as large as the largest maxUlary tooth. Maxil- 

 lary teeth tricuspid, close set at the upper part of the maxillary, more widely 

 spaced toward the lower end. Dentary with four or five tricuspid teeth of 

 about uniform size, the sides with about 10 abruptly minute teeth. 



Gill-rakers about 8 -|- 12. 



Scales cycloid, with many parallel striae, those below the lateral line with 

 short and deep exposed surfaces and emarginate edge, reg"ularly imbricate 

 except in front of the dorsal; scales of the pre ventral and predorsal areas small, 

 a narrow sheath of a single series of scales along the base of the anal. 



Origin of dorsal equidistant from snout and base of middle caudal rays. 

 Origin of anal under middle of dorsal. Origin of ventrals more than an orbital 

 diameter nearer snout than to the dorsal; ventrals reaching anal. 



Color of back dark, of sides much lighter, with a series of 8 or 9 dark brown 

 longitudinal lateral bands (between the rows of scales). A small, deep, brown 

 spot on each scale of lower half of body. Basal half of adipose fin in adult 

 black. Two vertical humeral spots, of which the posterior on the 6th, 7th, or 8th 

 rows of scales is darkest; both indistinct in adult. 



13. PsEUDOCHALCEUS Kuer. 



4'(rw5ris false, Chalceus, a genus of characins, from xaXKcios, 17, copper. 

 Psevdochalceus Kner, Sitzungsb. Akad. wiss. Munchen, 1863, p. 225. 



Type. — Pseudochalceus lineatus Kner. 



Mouth large; premaxiUary with two series of teeth, those of the outer 

 series much smaller than those of the inner, the middle pair of the inner series 

 much larger than the rest, each tooth with a large median cusp and a small 

 lateral cusp on each side; maxillary with a single series of similar teeth along 

 nearly its entire length. Mandible with a single series of irregulai'ly graduated 



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