THE AMERICAN TETRAGONOPTERINAE. 153 
Gill-rakers 4 + 10. 
One third of caudal scaled. Anal sheath of about 5 scales covering the 
basis of the first 8 anal rays. Lateral line with pores on 3 to 7 scales. 
Origin of the dorsal one third of the length of the eye nearer to the caudal 
than to the snout, its penultimate ray two fifths of the longest which is 3.5 in 
the length. Origin of the anal on the vertical from the seventh anal ray. Anal 
emarginate, the longest ray 1.33 in the length of the base. Caudal somewhat 
shorter than the head. Ventrals on the vertical from the second scale in front 
of the dorsal. Ventrals not quite reaching the anal; pectorals reaching a little 
beyond the origin of the ventrals. 
No shoulder-spot; a black lateral band beginning over the middle of pec- 
torals as a thin line, becoming gradually broader to the caudal peduncle where 
it expands more rapidly, abruptly contracted at the base of caudal but con- 
tinued for a short distance on the middle rays, the markings on the caudal 
being arrow-shaped. Back dusky, except the upper surface of upper caudal 
rays, and a spot behind the adipose. Fins all dusky. Spot on the back 
behind the adipose iridescent, yellowish, practically free from pigment. 
12. HermiGRAMMUS RODWAYI Durbin. 
Plate 2a ties. 
Hemigrammus rodwayi Dursin, Ann. Carnegie mus., 1909, 6, p. 58 (Georgetown Trenches), E1aenmMANN, 
Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 436; Mem. Carnegie mus., 1912, 5, p. 334, pl. 
48, fig. 3; Exurs, Ann. Carnegie mus., 1911, 8, p. 162 (Braganga; above Cachoeira, Rio Nova, Goyaz, 
Piabana). 
Hasrrat.— Lowland rivers from the Orinoco to Para, also Rio Nova. 
Specimens examined. 
Number of Length 
Catalogue number specimens in mm. Locality Collector 
1450 C. Type 1 46 Georgetown Trenches Eigenmann 
1451 C., 11906 I. 183 38-49 Georgetown Trenches Eigenmann 
Paratypes 
1452 C., 11907 I. 112 28-53 Botanic Garden, Georgetown Shideler 
1453 C., 11908 I. 4 24-26 Mud Creek in Aruka River Shideler 
1454 C., 11909 I. 7 34—40 Creek in Barima River Shideler 
3045 C. 6 31-40 Bragan¢a Haseman 
2 42-45 Georgetown Trenches Ellis 
12656 I. 3 31-36 Lama Stop-Off Eigenmann 
2949 C. 1 27 Above Cachoeira Rio Nova Haseman 
into Somno, into Tocan- 
tins, Goyaz 
