ANNOTATED LIST OF THE SPECIES 107 
Type: Pimelodus eques Miller and Troschel 
Range, that of the unique species 
Differing from the nearby Pimelodus and Pimelodella in the unequally lobed 
and rounded caudal fin, giving it an oblique form. 
49. GOELDIELLA EQUES (Miiller and Troschel) 
Pimelodus eques Miller and Troschel in Schomburgk, 1848, Reisen, III, 628; 
Bigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 166. 
Goeldiella eques Eigenmann and Norris, 1900, Revista Mus. Paulista, IV, 353; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 388; 
Higenmann, 1912, Mem. Carnegie Mus., V, 177. 
Entire Amazon and northward 
15968, 4, 97-185 mm., Iquitos, Morris, 1922. 
Head flat; a deep groove from the maxillary barbel to beneath the eye; anal fin 
peculiar in the rounded form of the free margin, the eighth ray the highest, 2 in the 
head; dorsal spine rather weak, 1.6 in the head; pectoral spine longer, 1.4 in head, 
and stronger; strong extrorse teeth on anterior border, and retrorse on the posterior. 
Gill-membrane edged with white; brownish general color, marbled with darker; a 
dark spot on shoulder sometimes continued across back, in front of dorsal spine, 
and backward as lateral band to caudal. 
Genus 17: DUOPALATINUS Eigenmann and Eigenmann 
Duopalatinus Eigenmann and Eigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 136; 
Bigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 200; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 391. 
Type: Platystoma emarginatum Cuvier and Valenciennes 
Rio Sao Francisco to the Ucayali 
Similar to brachyplatystoma, differing in that the vomerine and palatine patches 
of teeth, although uniform, are widely separated; caudal deeply forked, lobes long 
and pointed; head narrowed at gape; adipose longer than anal. 
50. DuOPALATINUS PERUANUS Eigenmann and Allen, sp. nov. 
Plate IV, fig. 4 
15798, 1, type, 176 mm., to end of middle caudal rays, Rio Puinagua, mouth of Rio Pacaya, Allen, 
August, 1920. 
Head 3.6; depth 5; D. I, 6; A. I, 9; head broader than deep, its width equal 
to its length less the opercle, its depth about equal to the length of the snout; eye 
with a free margin, a little nearer the end of the opercle than to the tip of the snout, 
7 in the head, 2.25 in interorbital; maxillary barbel extending past tip of caudal; 
outer mental barbel extending to the ventrals; inner mental barbels slightly beyond 
