152 THE AMERICAN CHARACIDAE. 
emarginate, the longest ray equal to the base. Anal armature developed on 
males. Ventrals on the vertical from the second scale in front of the dorsal. 
Ventrals reaching the first to third anal rays. Pectorals usually just reaching 
the ventrals. 
Humeral spot absent, (a small and faint round spot on two specimens). 
Caudal spot very dark, round or vertically elongate, entirely covering the 
middle caudal rays. Usually extending forward onto the caudal peduncle 
so as to give the spot a roughly triangular shape, placed rather below the 
middle of the peduncle. Scales of the back dusky; those on the sides above 
the narrow lateral stripe outlined with dusky. The first half of the anal rays, 
all of the dorsal, ventrals, and pectorals dusky. Scales below the lateral stripe 
with bright greenish iridescence. An uneven iridescent spot on the caudal 
peduncle above and in front of the caudal spot. 
11. Hemicrammus MATE! Eigenmann. 
Plate 19, fig. 1. 
Hemigrammus matei EIGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. 
One specimen 11438 I. Type 43 mm. Argentina 
Head 3.75-4; depth 3; D.10; A. 23; scales 5-32 to 34-3; eye 2.2 in 
the head, snout 2 in the eye, interorbital slightly less than the eye, 2.6 in the 
head. 
Compressed; depth of the head at the base of the occipital process, 1.5 
in the greatest depth. Preventral region rounded, without complete series of 
median seales. Predorsal region rounded, with complete median series of 10 
scales. 
Occipital process 5 in the distance from its base to the dorsal, bordered 
by 3. scales. Interorbital slightly convex. Frontal fontanel not narrower 
than the parietal, triangular and 1.25 in the length of the parietals without 
the occipital groove. Second suborbital in contact with the preopercle. 
Snout short and blunt, mouth large. Maxillary equal to or slightly less than 
the eye. Mandible a little longer than the eye, 2.14 in the head. Opercle 
incised above. Premaxillary with five or six 2- to 5-pointed teeth in the inner 
row and two or three similar but narrower ones in the outer row. Maxillary 
with three teeth, the posterior one 3-pointed, the anterior one 5-pointed. 
Dentary with graduated series of four or five teeth and several minute conical 
ones on the sides. 
