240 Fretp Museum or Natura History — Zod oecy, Vor. X. 
Body elongate; mouth terminal or with lower jaw the shorter; jaws 
with villiform teeth; no teeth on vomer or palate; nostrils remote from 
each other; no nasal barbels; barbels 6; occipital process small or want- 
ing, not reaching the dorsal plate; eye with a free orbital margin; dorsal 
fin with x slender spine and 5 to 8 branched rays; adipose fin long, adnate 
to the back. To this genus belongs a large number of fresh-water cat- 
fishes, inhabiting streams from southern Mexico to Peru and the Rio de 
la Plata. One species only occurs in the Panama Canal Zone region. 
1. Rhamdia wagneri (Gianther). 
Pimelodus cinerascens (non Ginther) Kner & Steindachner, Abhandl. 
K. Bayer. Ak. Wiss. Miinchen, 1865, 49 (Panama). 
Pimelodus wagnert Ginther, Trans. Zool. Soc. London, 1868, 474 
(Atlantic and Pacific rivers of Panama); Steindachner, Denkschr. 
K. Ak. Wiss. Wien, XLI, 1879 (Rio Mamoni, Chepo, Panama). 
Rhamdia bransfordi Gill, Proc. Ac. Nat. Sci. Phila., 1876, 337 (Panama). 
Rhamdia wagnert Eigenmann & Eigenmann, Occ. Pap. Cal. Ac. Sci. I, 
1890, 133 (Gorgona, Rio Chagres; Rio Obispo, Panama; Turbo, 
Atlantic coast, Cent. America); Jordan & Evermann, Bull. U. S. 
Nat. Mus., XLVII, 1896, 151; Regan, Biol. Cent. Amer., Pisces, 
1907, 131 (Shirures, Costa Rica; western Ecuador). 
Head 3.6 to 4.55; depth 5.1 to 6.55; D. I, 6; A. 11 to 13. 
Body elongate, compressed posteriorly; head depressed; profile 
gently elevated anteriorly, nearly straight; snout broad, its length 2.25 
to 2.5 in head; eye 5.45 to 7.5; interorbital 2.4 to 2.94; mouth broad, its 
width greater than length of snout; the upper jaw a little in advance of 
the lower; maxillary barbels varying considerably in length, reaching 
opposite base of ventrals to opposite or past base of anal; teeth in the 
jaws in villiform bands; none on palatines or vomer; head covered with 
skin; occipital process narrow, not extending to the small dorsal plate; 
fontanel long and narrow, extending past anterior margin of eye; dorsal 
fin with a poorly developed spine; origin of dorsal not quite half as far 
from tip of snout as from base of caudal; adipose fin notably longer 
than head, its base 2.65 to 3.3 in body; caudal fin forked, the lower lobe 
the larger, rounded; anal fin short, its origin somewhat nearer base of 
caudal than base of pectorals; ventral fins inserted behind vertical from 
base of last dorsal ray, failing to reach origin of anal; pectoral fins rather 
short, the spine rather weak, and without barbs except in young, its 
length 1.8 to 2.45 in head. 
Color bluish black above, pale below; sides yellowish green and with 
a single dark bandin young. Dorsal fin with a dark band across middle 
and a lighter one below it. 
