70 THE AMERICAN CHARACIDAE. 



scaled, but without a distinct median series, the scales along the ridge much 

 smaller than those of the sides. 



Occipital process reaching one third of the distance to the dorsal, bordered 

 by about five scales on each side; interorbital slightly convex; mouth small; 

 maxillary with the anterior margin convex, equal to snout and anterior width 

 of iris or snout and half the eye. Second suborbital leaving a considerable 

 naked area; maxillary with two teeth, premaxillary with four teeth in the outer 

 series, five in the inner; mandible with four strong teeth, five-pointed, abruptly 

 minute teeth on the sides. 



Gill-rakers about a third as long as the eye. 



Scales thin, with a few feeble diverging striae, margins convex; anal with 

 a sheath of two rows of scales; lateral line almost straight; no interpolated 

 rows of scales. 



Origin of dorsal considerably behind the ventrals, three in the length; 

 anal long, but little emarginate, its origin and base of last dorsal ray equidistant 

 from the snout; pectorals reaching about to middle of ventrals; ventrals not 

 to anal. 



A diffuse humeral band followed after a light band by a fainter dark band. 



This species is technically a Moenkhausia. In reality its relationship is 

 with Ephippicharax of another subfamily. It differs from Ephippicharax in 

 not having a movable predorsal spine. 



2. Moenkhausia latissima Eigenmann. 

 Plate 6, fig. 2. 



Moenkhausia latissimus Eigenmann, Bull. M. C. Z., 190S, 62, p. 101 (Tabatinga); Rept. Princeton univ. 

 exped. Patagonia, 1910, 3, p. 437. 



Habitat. — Tabatinga. 



Specimens examined. 



Number of 

 Catalogue number specimens Size in mm. Locality Collector 



207G2 



22 about 55-92 Tabatinga Bourget 



•iU/oy J 



This species, resembling Entomolepis steindachneri in its coloration, com- 

 pressed preventral region, and keeled predorsal area, is easily distinguished by 

 its entire scales, small nuchal scale, and much longer anal fin. 



