110 THE AMERICAN CHARACIDAE. 
two thirds to three in the head; three or four teeth in the outer series of the 
premaxillary, five teeth in the second series; two teeth in the maxillary. Lower 
jaw with four large teeth followed by a much smaller recurved tooth and a 
number of minute teeth. 
Gill-rakers 7 + 9, very short, the longest about one fifth the diameter of 
the eye. 
Seales very regularly imbricate, of comparatively uniform size, each with 
about five diverging striae, and with the surface minutely marked as in M. 
oligolepis. Caudal lobes sealed for at least half their length; scales above anal 
not decreased in size, at most four (34) scales between origin of anal and lateral 
line; anal with a basal sheath of a single series of scales in front, none posteriorly. 
A well-developed axillary scale. 
Dorsal a little nearer base of middle caudal rays than tip of snout, highest 
dorsal ray three and a half or four in the length; ventrals nearer tip of snout 
than the dorsal, equidistant from tip of snout and base of lower caudal rays; 
origin of anal equidistant from tip of snout and the second or third scale behind 
the dorsal; ventrals scarcely or not reaching anal; pectorals to near ventrals. 
Anal emarginate. 
Brassy, fins dusky. A very large and very conspicuous vertically oval 
black spot occupying all the base of the caudal (to near the tip of the middle 
rays), bordered behind, especially on the third, fourth, and fifth rays from the 
middle, by milk-white.’ 
The three cotypes from Para are much paler, the caudal spot while covering 
the same area is very faint except that part not covered by the caudal scales. 
In all the specimens from the Amazon Basin the lateral line is complete. 
It is also complete in one hundred specimens from Wismar, Malali, Tukeit, and 
Cangaruma. The first two of these localities are on the Demerara River, the 
second two on the Potaro River of British Guiana. Out of six specimens from 
below Wismar one has the line interrupted. 
In at least four out of six specimens from Christianburg, but one mile from 
Wismar, the lateral line is either interrupted or incomplete. 
In the Rockstone specimens it is incomplete. 
In the Crab Falls specimen the lateral line is developed on from ten to 
seventeen scales. 
In five specimens from Konawaruk the lateral line is incomplete. 
Out of the twenty-seven specimens from Tumatumari the lateral line is 
‘ In living specimens from British Guiana this spot is surrounded by rusty. 
