Pearson: Fishes of the Rio Beni Basin 
39 
Hemigrammus ocellifer (Steindachner) . 
17265, 1, 32 mm., Lagoons, Lake Eogoagua. Nov., 1921. 
Hemigrammus lunatus Durbin. 
17264, 2, 38-68 mm., Lagoons, Lake Eogoagua. Nov., 1921. 
17200, 32, 34-45 mm., Lagoons, Lake Eogoagua. Nov., 1921. 
17201, 2, 35 and 38 mm., Ixiamas. Dec., 1921. 
Hyphessobrycon callistus (Boulenger). 
17262, 25, 28-36 mm., Lagoons, Lake Eogoagua. Nov., 1921. 
17263, 9, 26-34 mm., Eeyes. Nov., 1921. 
Hyphessobrycon ellisi Pearson, sp. nov. Plate X, fig. 2. 
For Mrs. Marion Durbin Ellis. 
This species differs from Hyphessobrycon by having the 
second suborbital in contact with the preopercle below and 4 
teeth in the inner series of the premaxillary. It differs from 
Bryconamericus by having an incomplete lateral line. 
Gravid females show the largest specimens to be mature. 
17343, 55, cotypes, 24-38 mm., Espia. July, 1921. 
17344, 34, 27-36 mm., Tumupasa. Dec., 1921. 
17345, 34, 22-30 mm., Popoi Eiver, Upper Beni. Sept., 1921. 
Head 4; depth 3.8 to 4; D.10; A.15 to 17; eye 3 to 3 1/3; 
lateral line 4 — 33 to 35 — 2, incomplete, in some specimens only 
lacking 5 or 6 scales of being complete, in others not more 
than half of the scales with pores; body compressed; inter- 
orbital equal to the eye; maxillary with 2 polycuspid teeth; 
2 or 3 tricuspid teeth in the outer series of the premaxillary; 
4 five-pointed teeth in the inner series ; mandible with 4 or 5 
large five-pointed teeth followed by 5 or 6 smaller usually 
tridentate teeth ; gill rakers 6-|-7 ; second suborbital in con- 
tact with the preopercle below but leaving a wide naked mar- 
gin behind; many tactile papillae on the head appearing as 
tiny orange dots ; frontal fontanel small triangular, its length 
about 1/6 that of the diameter of the eye; the parietal slightly 
less than 1% times the diameter of the eye; snout rounded; 
predorsal area widely rounded back of the occipital process, 
with a narrow crest in front of the dorsal ; origin of the 
dorsal equidistant from the tip of snout and the base of the 
caudal ; pectorals not reaching ventrals ; ventrals scarcely 
reaching the anal ; origin of anal under the eighth dorsal ray, 
