106 FISHES OF WESTERN SOUTH AMERICA 
spine pungent, its anterior edge smooth, the posterior border with spines, its length 
1.1 times the length of the head; adipose fin separated from the dorsal by a distance 
equal to ? the base of the dorsal, its length 33-33 times in the total length; caudal 
deeply forked, the lobes narrow. 
Iridescent; humeral region darker; dorsal fin with the chromatophores col- 
lected on the interradial membranes; border of the adipose with many chromato- 
phores. 
For the dominant indigenous tribe of the region, the ‘“‘head-hunters’’, or Jivaros. 
Name supplied by W.R.A. 
48. PIMELODUS ALTISSIMUS Eigenmann and Pearson, sp. nov. 
Plate V, fig. 5 
15797, 1, type, 182 mm. to end of middle caudal rays, Rio Ucayali, near Orellana, Allen, August, 
1920. 
Characterized by the very long and very high adipose. Closely related to 
P. altipinnis, from which it differs by possessing a much higher dorsal spine, longer 
pectoral spines, and a steeper predorsal profile. 
Head 5; depth 4.85; D. I, 6; A. 12; eye 5.66; interorbital 3.5; width of the head 
1.38 in its length; convex above, the surface of the bones granulate; frontal fontanel 
ending above the posterior margin of the eye; occipital fontanel completely grown 
over; eye elliptical, its length 1.5 times in the interorbital; mouth inferior, the upper 
jaw projecting somewhat beyond the lower, exposing one half of the band of inter- 
maxillary teeth; intermaxillary band of teeth 3.5 times as broad as deep; no teeth 
on vomer; maxillary barbels compressed, their length 1.33 times the total length, 
outer mentals reaching slightly beyond the end of the middle caudal rays, the inner 
mentals slightly beyond the base of the ventrals; pectoral spine almost as long as 
the head, serrated along the posterior and anterior margins, 36 hooks along the 
inner margin; pectorals not quite reaching base of ventrals; ventrals not quite to 
the anal; distance of the origin of the dorsal from the tip of the snout 3.2 times in 
the total length; dorsal spine pungent, the anterior margin smooth, the posterior 
margin with a few very weak spines, its length 1.4 times in the length of the head; 
origin of the adipose immediately behind the base of the dorsal, its length 2.28 in 
the total length; caudal deeply forked, the lower lobe much narrower than the 
upper. 
Iridescent, an oblong dark spot above the tip of the humeral process; dorsal 
with the chromatophores thickest on the interradial membrane, the border of the 
adipose with many chromatophores. 
Genus 16: GOELDIELLA Eigenmann and Norris 
Goeldiella Eigenmann and Norris, 1900, Revista Mus. Paulista, IV, 353; 
Bigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 388; 
Eigenmann, 1912, Mem. Carnegie Mus., V, 177. 
