474 DR, GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
its length being equal to, or a little less than, that of the head. The anal fin terminates 
behind the adipose fin, and its last rays do not extend to the base of the caudal. Axil 
of the pectoral with a very distinct porus mucosus. ‘The pectoral spine is serrated 
interiorly, sometimes a little longer, sometimes a little shorter, but always rather stronger 
than that of the dorsal fin. Pectoral fin longer than ventral, two-thirds or three-fifths 
of the length of the head. ‘The ventral extends to the origin of the anal. Upper parts 
brownish, with steel-blue reflexions; lower parts silvery, with a reddish tinge. 
Three examples were collected by Mr. Salvin in the Rio Usumacinta; the largest is 
15 inches long. 
205. PIMELODUS WAGNERI. 
Pimelodus cinerascens, Kner & Steindachner, Abhandl. bayer. Akad. x. p. 49 (not Gthr.). 
D.1/6, <A. 11-12. 
Head covered with soft skin above. Adipose fin one-third of the total length (without 
caudal). The maxillary barbels extend beyond the root of the yentrals; the outer ones 
of the mandible do not quite reach the base of the pectorals. The length of the head 
is contained from five times and two-fifths to five times and seven-eighths in the total 
(with the caudal), the height of the body seven times and one-third, or seven times and 
one-half. Upper jaw projecting beyond the lower. ‘The eye is equidistant from the 
end of the snout and from that of the gill-cover; its diameter is one-seyenth or one- 
eighth of the length of the head, and contained twice and two-thirds or twice and 
three-fourths in the width of the interorbital space. Dorsal fin with the spine very 
feeble, as high as long. Pectoral fin two-thirds as long as head. Porus axillaris 
small. Coloration uniform, a darker streak along the lateral line; dorsal fin with the 
usual whitish cross band, and sometimes with a large round black spot between the 
last two rays. 
Pacific and Atlantic rivers of Panama. 
The complete diagnosis of P. cinerascens (Gthr.), accompanied by a most accurate 
figure, proves at once that the species discovered by Hr. Wagner is distinct from it. It 
appears to be nearest to P. godmanni. 
206. PIMELODUS MANAGUENSIS. , 
D. 1/6. » A, 14-15, P.1/9. 
Head covered with soft skin above; occipital process styliform, not extending to the 
basal bone of the dorsal spine, Adipose fin yery long, rather more than one-third of 
the total length (without caudal); its distance from the dorsal is equal to the length of 
the base of the latter. The maxillary barbels are rather short, extending nearly to the 
base of the dorsal fin, the outer ones of the mandibles reach beyond the root of the 
pectoral. The height of the body is contained six times in the total length (without 
