196 THE AMERICAN CHARACIDAE. 
Maxillary equal to the eye. Mandible 2.5 in the head. Premaxillary with 
an inner row of five 5-pointed, and an outer row of four 3-pointed teeth. Maxil- 
lary with four or five rather small tricuspid teeth. Dentary with a graduated 
series of four large, 5-pointed, one small, 3-pointed and five or six minute conical 
teeth. 
Gill-rakers 6 + 9. 
Caudal seemingly naked. Lateral line with pores on 9 or 10 scales. 
Origin of the dorsal equidistant from the caudal and snout. Origin of 
the anal on the vertical from the second dorsal ray. Anal emarginate. Ven- 
trals on the vertical from about the fourth scale in front of the dorsal. 
Ventrals just reaching the anal or a little further. Pectorals reaching the 
ventrals. 
Fins all dusky, the middle rays of the caudal black. Humeral spot indis- 
tinct, large, oval, and horizontally elongate. A broad leaden lateral stripe. 
Seales of the back outlined with pigment. 
19. HyPpHESSOBRYCON MELAZONATUS Durbin. 
Plate 26, fig. 4. 
Hyphessobrycon melazonatus Dursrn, Bull. M. C. Z., 1908, 62, p. 101 (Lago do Maximo; Silva, Lake 
Saraca); ErapNMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436. 
Hapitrat.— Amazon. 
Specimens examined. 
Catalogue Number of 
number specimens Size in mm. Locality Collector 
20737 Type 1 about 38 Lago do Maximo Agassiz 
21069 Paratype 1 about 34 Silva, Lake Saraca Thayer 
20995 1 36 Serpa Thayer Exped. 
Head 3.5; depth 2.66-2.5; D. 11; A. 22; scales 5-34-3.5; eye 2.66 in 
head; interorbital equal to the eye. 
Compressed, deepest at the origin of the dorsal; depth of head at the 
base of the occipital process 1.67 in the greatest depth. Preventral region 
rounded, without complete series of median scales. Predorsal region rounded, 
with complete median series of 9 scales. 
Occipital process 5 in the distance from its base to the dorsal, bor- 
dered by 2 to 2.5 seales. Interorbital slightly convex. Frontal fontanel trian- 
gular, as wide as and nine tenths as long as, the parietal without the occipital 
