ANNOTATED LIST OF THE SPECIES 93 
not produced; barbels terete or flat. Fontanels obsolescent, occipital obsolete; 
free orbital margin. 
19. RHAMDIA DUQUET Eigenmann and Pearson, sp. nov. 
Bagre 
, 36, type and paratypes, 48-135 mm., Rio Urubamba, Santa Ana, Kigenmann, November, 
1918. 
Very closely related to R. micayi, from which it differs in the shorter adipose. 
Head 4—4.25; depth 5.87; D. I, 6; A. 12; eye 6-7; interorbital 3.5—4 in the head; 
width of the head in its length 1.4; flat above, the surface covered with thin skin, 
the surface of the bones striate; frontal fontanel not extending past the eye; occipital 
fontanel present in the young, remaining in the adults as a circular depression; 
occipital process extending ? of the distance from its base to the origin of the dorsal; 
eye elliptical, 1.5-1.8 in the interorbital width; teeth of the upper jaw in an un- 
interrupted band, the depth 7 or slightly less in the width; gill-rakers simple, slender, 
3-6; maxillary barbels compressed or filiform, extending to the middle of the ven- 
trals or slightly beyond; outer mental barbels to slightly beyond the base of the 
pectorals, inner mentals slightly beyond the gill opening; pores on the head regu- 
larly distributed; pectoral spine 2—2.5 in the head, the posterior margin slightly 
roughened, the anterior margin with 8 conspicuous recurved teeth in a specimen of 
100 mm.; ventral inserted below the last dorsal ray; anal fin higher than long, the 
tips reaching to below the end of the adipose when depressed; distance of the dorsal 
fin from the snout 2.8-38 times in the total length. Dorsal spine pungent, 3.2-3.6 
times in the head, its anterior margin rough; adipose fin separated from the dorsal 
by a distance equal to or slightly greater than the base of the dorsal, 3.5-8.8 in the 
total length; caudal deeply forked; the lower lobe rounded, broader than the upper. 
Color brown; humeral region darker; predorsal line dark; a dark area on the 
top of the head; dorsal with a light, transparent band, chromatophores above the 
band collected along the posterior edge of the interradial membrane; the other fins 
dusky. 
For Don Carlos Duque of Santa Ana, whose hospitality and active participa- 
tion have contributed to the success of this expedition and others in the Urubamba 
valley. Name supplied by W.R.A. 
20. RHAMDIA QUELEN (Quoy and Gaimard) 
Pimelodus quelen Quoy and Gaimard, 1824, Voy. Uran. Zool., pl. xlix, figs. 8-4. 
Rhamdia quelen Eigenmann and Kigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 126, Brazil; 
Eigenmann and Higenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 127. 
Pimelodus quelent Giinther, 1864, Cat. Fish. Brit. Mus., V, 123, Brazil. 
Rhamdia queleni Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 101. 
Amazons to the basin of Rio de la Plata 
15791, many, 50-282 mm., creeks at Yurimaguas, Allen, November, 1920. 
15792, 157 and 172 mm., Iquitos, Allen, 1920. 
