22 
Indiana University Studies 
membrane arranged in 3 oblique rows across the fin; the 
caudal with 3 dark irregular bars ; the pectorals and ventrals 
spotted between the rays, the spots more or less arranged in 
oblique lines. The young with 3 broad bars across the back ; 
the first thru the dorsal extending from the third to the last 
ray, the second from the second scute in front of the adipose 
to its middle, the third an indistinct bar across the base of 
the caudal, in the adult these bars become broken up into 
spots; the dorsal with the interradial spots arranged in 3 
rows across the fin ; the caudal with 3 distinct cross bars. 
Very closely related to P. latirostris. The following table 
gives comparisons : 
Head 
Depth 
Eye 
Depth of head in length 
Snout in head 
Mandibular ramus in interorbital 
Supraoccipital edges 
Scutes in longitudinal series 
Caudal peduncle in length 
Marking of fins 
P. latirostris 
P. bolivianv 
3 to 3M 
3 
4 2 / 5 to 5 
5 
53^ to 7 
6 to 9 
1.6 to 1.66 
1.9 
1.75 
1.7 
1.5 to 1.8 
1.3 
raised 
not raised 
25 to 27 
26 
2.5 to 3 
2.8 
without spots 
spotted 
Rhinelepis levis Pearson, sp. nov. Plate V, figs. 1-3. 
17014, 4, type and paratypes, the largest the type, 129-155 mm., Huachi, 
Bolivia. Aug., 1921. 
17015, 4, 60-94 mm., Popoi River, Upper Beni, Bolivia. Sept., 1921. 
Head 3 1/ 2 ; depth 5 to 5V 3 ; D.1,7; A.I,4; eye 1% to 7%; 
head 11/7 times as long as broad; l 3 / s as long as deep; the 
interorbital width 2 1 / 6 to 2y 3 times in the head, the snout 
l 3 / 5 times; the mandibular ramus 3 1 /., to 3^2 times in the 
interorbital width ; snout ovate ; the position of the eye 1/2 the 
distance between the tip of the snout and the origin of the 
dorsal ; 29 scutes in a longitudinal series, 15 between the anal 
and the caudal, only the first 4 scutes above the pectoral cari- 
nate; supraoccipital with a wide, low ridge, bordered poster- 
iorly by a single scute; the lower surface of the head and 
abdomen with small granular plates; the first dorsal ray 
equal to the head in length, the last 15/7 times in the head; 
the distance between the tip of the snout and the origin of the 
dorsal 2.6 times in the total length ; the pectoral spines extend 
to the anterior third of the ventrals ; the base of the dorsal is 
% the length of the head, no trace of an adipose fin ; the caudal 
