188 THE AMERICAN CHARACIDAE. 
11. HyYpHEssoBRYcoN GRACILIS (Reinhardt). 
Plate 22, fig. 4; Plate 26, fig. 2; Plate 79, fig. 7. 
Tetragonopterus gracilis RernHARpDT in Liitken, Overs. K. Dan. selsk. Forh., 1874, p. 133 (Lagoa Santa); 
LiirKen, Velhas-Flodens fiske, 1875, p. 217, pl. 5, fig. 16, (Rio das Velhas); Ercenmann & 
EIGENMANN, Proc. U.S. N. M., 1891, 14, p. 53; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 286; 
Boulenger, Boll. Mus. univ. Torino, 1895, 10, no. 196, p. 3 (Villa Rica). 
Hemigrammus gracilis EIGENMANN & OGLE, Proc. U. 8. N. M., 1907, 38, p. 15 (Lagoa Santa); ErGEn- 
MANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Mem. Carnegie mus., 1912, 5, p. 
340, pl. 44, fig. 4. 
Tetragonopterus schmardae ULRryY, (non Steindachner), Ann. N. Y. acad. sci., 1895, 8, p. 286 (Para). 
Hasirat.— San Francisco, Paraguay, Amazon Basin, and British Guiana. 
Specimens examined. 
Catalogue Number of Length 
number specimens in mm. Locality Collector 
21008 1977 24-30 Brazil Justa 
5176 I. 4 20-24 Para, Brazil Hartt 
Sia as 1 27 Lower Amazon Hartt 
20812 1 44 Ica James 
1247 C., 11772 I. 16 19-24 Gluck Island Eigenmann 
Head 3-3.5; depth 3-3.5; D. 10, occasionally 11; A. 17-24'; scales 5-29 
to 34-3.5 or 4; 6 to 13 pores in the lateral line; eye 2—2.5 in the head; interorbi- 
tal little less than the eye, 2.7—3 in the head. 
Compressed; head short, depth of head at the base of the occipital process 
1.5 to 1.25 in the greatest depth. Preventral region rounded, with a regular 
median series of 9 to 12 scales. Predorsal region rounded, not keeled, with a 
regular median series of 9 scales. 
Occipital process 5 in the distance from its base to the dorsal, bordered 
by 2 to 2.5 scales. Interorbital slightly convex. Frontal fontanel triangular, 
narrow, and equal to the length of the parietal without the occipital groove. 
Second suborbital leaving a naked border about one third of its own width; 
third suborbital small. Maxillary not quite equal to the length of the eye. 
Mandible a little longer than the eye. Snout short. Premaxillary with five 
3- to 5-pointed teeth in the inner row, and two to four tricuspid teeth in the 
outer row. Maxillary with one to three very small tricuspid or conical teeth 
that are usually very difficult to see. Dentary with four, less frequently five 
1 The anal in No. 21008 varies from 17-20, in 5176 from 22-24, in 2812 there are 24, and in 5177 
there are 21 anal rays. 
