78 THE AMERICAN CHARACIDAE. 



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

 and the dorsal, bordered on the side by three scales. Second suborbital leaving a 

 naked border distinctly wider than in M . chrysargyreus; maxillary rather longer 

 than the distance from tip of snout to pupil, a little more than three in the head. 



Three to six teeth 1 in the front row of the premaxillary, five or six in the 

 second row; maxillary with two small teeth; mandible with four large teeth 

 and numerous small ones on the side. 



Gill-rakers 7 + 15, a little more than half the length of the pupil. 



Scales regularly imbricate, each with a few divergent striae, the exposed 

 portion of those on the caudal peduncle about two thirds of the depth of the 

 exposed portions of those on the middle of the sides; anal sheath composed of 

 two scales in front ; (all but one of the caudal scales missing) ; lateral line but 

 little decurved. 



Origin of dorsal a little nearer tip of snout than to caudal, the anterior rays 

 elevated, three in the length, reaching adipose when depressed; caudal lobes 

 equal to height of dorsal; origin of anal equidistant from tip of snout with a 

 point midway between the dorsals, the margin damaged but evidently emargi- 

 nate, the highest anterior ray reaching at least to the base of the seventh from 

 the last when depressed; ventrals reaching anal, one and a half in the head, 

 their origin equidistant from tip of snout and caudal; pectorals reaching beyond 

 origin of ventrals. 



A deep lying, well-defined humeral spot, beginning in a point above the 

 origin of the lateral line increasing in width backward and ending above the 

 seventh scale of the lateral line; a very narrow, silvery lateral line; upper poste- 

 rior part of the interradial membranes of the dorsal dark; remaining fins hyaline. 



Vertebrae 11 +19. 



8. Moenkhausia melogramma Eigenmann. 

 Plate 6, fig. 1; Plate 100, fig. 4. 



Moenkhausia melogrammus Eigenmann, Bull. M. C. Z., 1908, 52, p. 102 (Tabatinga); Rept. Princeton 

 univ. exped. Patagonia, 1910, 3, pt. 4, p. 437. 



One specimen 20825 Type 40 mm. to base of caudal Tabatinga Bourget 



Readily distinguished by the depth and by the black line along the base 

 of the anal. 



1 In the type there are four on the left side and five on the right, hut one has evidently been lost 

 from the latter; in the second specimen there are five on the left and three on the right side. 



