THE AMERICAN TETRAGONOPTERINAE. 143 
4. HEMIGRAMMUS ELEGANS (Steindachner). 
Plate 17, fig. 3. 
Tetragonopterus elegans STEINDACHNER, Flussf. Siidam., 1882, 4, p. 36, pl. 7, fig. 4 (Obidos); E1raeNMANN 
& E1cenmann, Proc. U.S. N. M., 1891, 14, p. 285; Unrey, Ann. N. Y. acad. sci., 1895, 8, p. 285. 
Hemigrammus elegans EIGENMANN & OL», Proc. U.S. N. M., 1907, 33, p. 12; Ercenmann, Rept. Prince- 
ton univ. exped. Patagonia, 1910, 3, p. 436. 
Hasitrat.— Amazon. 
Specimens examined. 
Number of 
Catalogue number — specimens Size in mm. Locality Collector 
20734 4 27-30 Santarem Bourget 
20869 1 35 Tapajos Dexter, James, 
& Talisman 
20840 ! Lh te 28 Obidos James 
Head 3.5-3.67; depth 2.67-3; D.11; A. 23 or 24; scales 5-30 to 33-4.5; 
eye 2.25-25; interorbital 3. 
Compressed; depth of head at base of occipital process 1.75 in the great- 
est depth. Preventral region rounded; no regular series of median scales. 
Predorsal region rounded, with a regular median series of 9 scales. 
Occipital process one fourth of the distance from its base to the dorsal, 
bordered by three scales, interorbital almost flat; frontal fontanel almost equal 
to the parietals without occipital groove. Second suborbital leaving a narrow 
naked area behind and below. Mouth large. Maxillary barely as long as the 
eye, mandible equal to the eye. Snout very blunt, equal to half the length 
of the eye. Premaxillary with an outer series of three 5-pointed teeth, and 
an inner series of five teeth, the center one of which has five cusps, the next 
three to six cusps each and the end one seven. The maxillary with three, 
5-pointed teeth broader than those of the outer premaxillary series. Dentary 
with five, 3- to 5-pointed teeth followed by a few conical ones on the sides. 
Gill-rakers about 7 + 10. 
Caudal only partially scaled. Anal sheath of six scales covering the bases 
of the first seven rays. Lateral line with pores on from seven to eleven scales, 
not decurved. 
Origin of dorsal a very little nearer snout than caudal. Penultimate ray 
three in the longest which is 2.75 in the length. Caudal probably equal to 
1 In part. 
