94 THE AMERICAN CHARACIDAE. 



Specimens examined. 



Catalogue Number of Size 



Head 4; depth 2.25-3.25; D. 11; A. 26-28; scales 5-32 to 34-3.5. Eye 

 2.6 in the head; interorbital equal to the eye or a little narrower. 



Much compressed, the depth varying greatly; dorsal and ventral outline 

 regularly and nearly equally arched; area immediately in front of ventrals flat, 

 region between the pectorals bluntly keeled, about fourteen scales in the median 

 series in front of the ventrals; predorsal area bluntly keeled, with a median 

 series of ten scales. 



Occipital process about one fifth of the distance from its base to the dorsal, 

 bordered by three scales on each side; interorbital convex; frontal fontanel dis- 

 tinctly shorter than the parietal without its groove. 



Third suborbital covering the entire cheek, leaving but a small naked tri- 

 angle under its anterior corner; mouth small, the antero-posterior extent of the 

 premaxillary very small, maxillary large, about as long as the eye, its anterior 

 margin convex; the mouth similar to that of M. dichrourus. Teeth all feeble, 

 each ramus of the mandible with five or six graduate teeth, of which the second 

 is more forward, out of line with the rest, forming an incipient second series, 

 sides of the ramus with about seven to ten minute conical teeth; premaxillary 

 with three to five teeth in the outer row, five in the inner; maxillary with or 

 without a microscopic conical tooth. 



Gill-rakers slender, about equal to the snout in length, 11 + 14. Scales thin, 

 entire, with widely diverging radiae; no interpolated scales; anal with a feeble 

 sheath of one series of scales in its front half; caudal lobes densely scaled to near 

 the tip, the central rays nearly naked. 



Dorsal pointed, the first rays about three and a half in the length; anal 



1 Specimens only fifteen mm. long have the characteristic coloration. 



