Ellis: Hasemania, Hyphessobrycon, \\i> Hemigrammus. L49 



depth "i head al the base of the occipital process 1.2 in the greatesl 

 depth. Preventral region rounded. Predorsal region rounded, with- 

 out .1 regular series of median scales. Occipital process ,1 little 

 more than 5 ' n the distance from its base to the dorsal. Inter- 

 orbital nearly flat. Frontal fontanels triangular, as wide as the 

 parietal, and two thirds as long as the parietal without the occipital 

 groove. Second suborbital with a wide naked margin behind and 

 below. Snout [jointed, rather short, mouth large. Maxillary equal 

 to the eye. Mandible longer than the eye, 2.4 in the head. Pre- 

 maxillary with five tricuspid and conical teeth in the inner row, 

 and three conical teeth in the outer row. Maxillary with two coni- 

 cal teeth. Dentary with five or six tricuspid teeth, followed by 

 three to six very small conical teeth on the sides. Gill-rakers 6 + 9. 

 Scales cycloid, striae crooked, more numerous near the sides of the 

 free margin of the scale, variable in number (18 +). Caudal naked. 

 No anal sheath extending over the rays of the tin, but a series, or 

 part ot a series, of small scales along the base of the anal. Lateral 

 line with pores developed on about six scales. Origin of the dorsal 

 tin length of the eye nearer to the caudal than to the snout, its long- 

 est ray about 4.5 in the length. Caudal probably about 1.33 in 

 the head. Origin of the anal on the vertical from the ninth dorsal 

 ray. Anal truncate. Yentrals on the vertical from the first dor- 

 sal ray, very short, just reaching the second scale in front of the 

 anal. Pectorals archaic. Adipose lacking. Xo humeral spot, a 

 faint caudal spot, not continued on the rays. Lateral stripe very 

 faint. Dorsal, caudal, and ventrals uniformly dusky; distal half 

 of anal dusky. All the scales, excepting those in the preventral 

 region, outlined with dusky; much darker along the back. Silvery 

 except along the back. 



2. Hasemania melanura sp. nov. 



Plate I, fig. 2. 

 Type, one specimen, 35 mm. C. M. No. 3002. Porto Uniao, Rio I.utmssu. 

 Cotypes, forty-nine specimens, 25 to 44 mm. C. M. No. 3003. Porto t 

 Rio Iguassii. 



Head 3.2 to 3.7; depth 2.6 to 2.8; D. 11 ; A. 16 to 18; scales 6-33 

 to 3 0- 5; eye rather small, 3 in the head; interorbital equal to, or 

 greater than, the eye, 2.8 to 3 in the head. Compressed, depth 

 "of head at the base of the occipital process 1.6 in the greatest depth. 



