239 
PIMELODUS MODESTUS, B. sp. (Pl. X. fig. C.) 
B.6. D.1/6. A.4/8. V.1/5. P. 1/8. 
The body is rather elongated, slightly compressed posteriorly ; head 
moderately broad and long, depressed, truncated anteriorly ; its 
length is contained five times and a half in the total length of the 
fish. The snout is somewhat produced, broad, contained twice and 
three-fifths in the length of the head, truncated, with the upper jaw 
longest. The distance between the angles of the mouth is nearly 
equal to the length of the snout. Six barbels: that of the maxillary 
reaches to the origin of the anal; the exterior pair of the mandibu- 
lary barbels are two-thirds the length of the interior, and extend to 
the middle of the pectoral fin; the interior pair are inserted some- 
what before the outer ones, and rather more remote from each other 
than from the outer ones. The diameter of the eye is one-fourth of 
the length of the head, and equals the width of the interorbital 
space; it is situated in the middle of the length of the head. The 
head is covered superiorly with a very thin and smooth skin; the 
occipital process is long, and extends on to a triangular plate in front 
of the dorsal; this plate is also covered with skin, like the head. 
The lower edge of the operculum is straight; the spine of the hu- 
meral bone very indistinctly striated. The depth of the body, taken 
below the origin of the dorsal, is one-seventh of the total length ; 
that of the tail one-thirteenth. The pectoral extends on to below 
the middle of the dorsal fin ; its spine is not much shorter than the 
Tays, stout, compressed, with the interior edge spiny. The ventral 
has the first ray undivided, flexible; it is inserted immediately be- 
hind the vertical from the dorsal, and does not extend on to the 
anal. The dorsal is somewhat higher than long, and has the upper 
profile convex; the length of its base is nearly equal to its distance 
from the head ; the spine is slender, stiff, pungent, rough superiorly, 
and terminating in a ray-like filament. The adipose fin is very long, 
its distance from the dorsal and caudal fins being nearly equal. 
Caudal deeply notched, with the lobes pointed ; the upper lobe is 
longer than the inferior, and its length is 4? in the total. The four 
anterior rays of the anal are short, flexible, undivided ; the margin of 
the fin is convex, and the length of its base is 12 in its distance 
from the caudal. Above light greyish, beneath whitish. 
Hab. Fresh waters of Esmeraldas. 
inches. lines. 
Wig WOE eee Sore eect 8 os ue le 
Lenpth of thedibgiss o...5 5. 0c osgn es om 0 102 
— of the snout......... Se seein tae od 0 4 
Distance between the eyes .............. 0 = 
Distance between the angles of the mouth.. 0 42 
Diameter of the eye...........0.: Reitavespre yy 3aae 
BICHON 0 CNG CRORE art ce ns cawcais's a oss 3 Oe 
mem UNS Me os a oe vn ee os ose 0 43 
of the second dorsal ray........ Rymededl | obieg > - 
Length of the upper caudal lobe.......... aM OcN 
