10 
Indiana University Studies 
its definite relationship. It probably belongs to the subfamily 
Pimelodinse and seems more closely related to the genus Pseu- 
dopimelodus with which it agrees in having a broad head and 
a relatively short adipose. 
D. I. 6; A. 13?; width of the head equal to its length less 
the opercle ; mouth terminal ; snout equals the interorbital ; 
center of the eye a little in advance of the center of the head ; 
orbit without a free margin; giil-membrane broad, separate 
to below the angle of the mouth ; nares remote, the anterior 
ones at the tip of the snout ; teeth in bands, sharp, conical : 
maxillary barbel extending to the base of the ventrals ; the 
outer pair of mental barbels extending to the base of the 
pectorals, inner mentals not quite to below the posterior mar- 
gin of the eye; pectorals very wide and long, extending 
almost to the anal ; ventrals about half the length of the 
head, their origin very slightly posterior to the base of the 
last dorsal ray ; adipose fin moderately long, sharply demarked, 
continued forward as a thin membrane; origin of the dorsal 
about the third fifth of the body; dorsal spine pungent, short 
and feeble, not 1/3 the length of the longest ray. 
Interorbital 3 mm. ; eye 1 mm., distance between snout and 
dorsal spine 9 mm.; distance from dorsal spine to caudal 13 
mm. ; distance between origin of ventrals and caudal 11 mm. ; 
middle caudal rays 3 mm. ; caudal lobes 10 mm. ; adipose 2 
mm. long; highest dorsal ray 4 mm.; pectoral fin 7.5 mm. 
Anal, middle of caudal and opercular margin hyaline ; other- 
wise black. 
Pseudopinielodus zungaro (Humboldt) . 
17036, 5, 112-160 mm,, Huachi and Popoi rivers, Upper Beni. Sept., 
1921. 
17037, 10, 112-228 mm., Rio Colorado, Lower Bopi. Sept., 1921. 
The above specimens differ from specimens from Colombia 
by possessing weaker dorsal and pectoral spines and a slightly 
longer caudal peduncle. 
Cetopsorhamdia nasus Eigenmann & Fisher. 
17270, 4, 78-120 mm., Popoi River, Upper Beni. Sept., 1921. 
17271, 3, 56-78 mm., Tumupasa. Dec., 1921. 
This species has hitherto been found in Western Colombia. 
