THE AMERICAN TETRAGONOPTERINAE. 219 



Allied to H. panamensis from which specimens of equal size differ in the 

 wider second suborbital, the broader predorsal area, the smaller eye, the shorter 

 anal, the color, etc. 



35. Hyphessobrycon heterorhabdus (Ulrey). 



Plate 28, fig. 3; Plate 79, fig. 10. 



Tclragonopla-iis heterorhabdus Ulrey, Ann. N. Y. acad. sci., 1895, 8, p. 286 (Para; Brazil). 

 Hemigrammus heterorhabdus, Eigenmann & Ogle, Proc. U. S. N. M., 1907, 33, p. 14. 

 Hyphessohrycon heterorhabdus, Eigenmann, Rept. Princeton univ., Exped. Patagonia, 1910, 3, p. 437; 

 Ellis, Ann. Carnegie nius., 1911, 8, p. 159 (Braganga). 



Habitat. — Lower Amazon. 



Catalogue Number of Size 



number specimens in mm. Locality Collector 



5496 1. Cotypes 8 6-26 Brazil Hartt 



5500 1. Cotj'pes 5 17-24 Para Hartt 



3004 C. 2 29, 33 (about) Bragarifa Haseman 



Head 3.5-3.75; depth 3-3.5; D. 10; A. 20-23; scales 5-32 to 34-3; eye 

 2.5 in the head; interorbital equals the eye. 



Compressed. Depth of head at the base of the occipital process 1.25 in the 

 greatest depth. Preventral region rounded, without complete series of median 

 scales. Predorsal region rounded, with complete series of 11 median scales. 



Occipital process 6 to 7 in the distance from its base to the dorsal, bordered 

 by 2.5 to 3 scales. Interorbital convex. Frontal fontanel triangular, four 

 fifths the length of the parietal without the occipital groove. Second suborbital 

 leaving a naked margin behind and below. Maxillary equal to the eye. Man- 

 dible almost imperceptibly longer. Mouth large. Premaxillary with four 

 or five, 3- to 5-pointed teeth in the inner, and four conical or narrowly tricuspid 

 ones in the outer row. Maxillary with four conical teeth. Dentary with a 

 graduated series of four, 3- to 4-pointed teeth and three or four minute conical 

 ones on the sides. 



Gill-rakers 7 + 12. 



Anal sheath short, probably of about three scales. Lateral line with pores 

 on 8 or 9 scales. 



Origin of the dorsal equidistant between the snout and caudal, the penulti- 

 mate ray 2.5 to 3 in the longest, a little less than 4 in the length. Origin of the 

 anal on the vertical from the last dorsal ray. Anal emarginate. Ventrals 

 on the vertical from the second scale in front of the dorsal. Ventral not reach- 

 ing the anal; pectorals not reaching the ventrals. 



