58 



THE AMERICAN CHARACIDAE. 



bent scales, bordered on the sides with small asymmetrical scales, the area com- 

 pressed; predorsal region keeled; predorsal scales small, crowded, the median 

 series of scales (12-16) reaching to occipital process. 



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

 bordered by from five to seven scales on each side, the groove of the occipital 

 fontanel reaching to its tip; interorbital convex; second suborbital not covering 

 the entire cheek; maxillary equal to the distance from tip of snout to pupil. 

 From five to seven (rarely four to eight) teeth forming a continuous front series 

 of the premaxillary, the third (in one case the fourth) usually withdrawn some- 

 what from a straight line. Five (rarely four or six) teeth in the inner row; 

 maxillary with three (rarely one, two, or four) small teeth. Lower jaw with 

 four, or very rarely five, large teeth; the second largest, graduated to the fourth 

 or fifth; many small teeth on the side. 1 Gill-rakers about 9 + 13, the longest 

 one third the diameter of the eye. 



Scales deeply imbricate, an occasional line on the scales of the sides, lines 

 more numerous on those near the caudal; scales of the sides continuous with 

 the anal sheath consisting of three or four rows of scales in front and tapering 

 to a single series on the last ray. Lateral line obliquely descending on the 

 first seven scales, then nearly straight; a well-developed axillary scale; caudal 

 lobes scaled for about half their length. Origin of dorsal about equidistant from 

 tip of snout and base of middle caudal rays, its first divided ray two and one half 

 times as long as the last, three times in the length. 2 Anal in the adult low, its 

 margin nearly straight; in the young the anterior rays are higher than the rest. 

 Origin of ventrals much nearer tip of snout than the dorsal, equidistant from 



1 An examination of a variety of specimens gives the number of teeth in the: 



In this table the first line of figures gives the different numbers of teeth found on the structures 

 mentioned above and the following lines represent the number of individuals having the given number. 



2 In the specimen from Tumatumari the first divided ray is three and one half times as high as the 

 last ray which is two thirds the length. 



