130 FISHES OF WESTERN SOUTH AMERICA 
A 35 mm. specimen in the collections of the Philadelphia Academy of Sciences, 
collected from the Rio Ambyiacu by John Hauxwell. 
Genus 42: PSEUDODORAS Bleeker 
Pseudodoras Bleeker, 1858, Ichth. Arch. Indici., Siluri, 53, Doras niger Valenciennes; 
Eigenmann, 1925, Trans. Amer. Phil. Soc., XXII, 331. 
Oxydoras Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 14, D. niger. 
Type: Doras niger Valenciennes 
Peru to the Guianas and Rio Sao Francisco 
The genus Pseudodoras was abandoned by Bleeker on grounds shown by 
Eigenmann to be based on false assumptions of Kner. It therefore has priority 
over the Oxydoras of Kner with Doras niger Valenciennes as its type. 
This and succeeding genera are characterized by less breadth than the preced- 
ing, the width at the clavicle less than the length of the head. 
Adipose continued forward as a low ridge longer than the anal; eye laterally 
oriented, back of middle of the head; dorsal spine with serrae antrorse or vertical 
to it on the posterior margin; the serrae of the anterior margin stronger and more 
numerous; fontanel with a bridge; lateral plates not numerous, 3 + 18-238; head 
not depressed, snout conical, mouth inferior; premaxillaries rhomboidal; anterior 
nares remote from lips; caudal emarginate. 
Groups of tentacles on the roof of the mouth before the first gill arch and 
between the second and third pairs; air bladder double; first division cardiform with 
the beginnings of coeca; the second twice as long as wide, and less than two in the 
length of the anterior chamber. 
87. PSEUDODORAS NIGER (Valenciennes) 
Doras niger Valenciennes, in Humboldt, 1833, Rec. d’Obs. Zool. Anat., II, 184; 
Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 291; 
Kigenmann, 1912, Mem. Carnegie Mus., V, 190, Rupununi. 
Pseudodoras niger Bleeker, 1858, Ichth. Arch. Indici, Siluri, 53; 
Eigenmann, 1925, Trans. Amer. Phil. Soe., XXII, 333, pl. i, fig. 16; pl. xvii, figs. 1-4; pl. 
xxiii, fig. 1; text figs. 2, 6, 7, and 10; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sci. Phila., XCI, 228, Contamana. 
Rhinodoras niger Giinther, 1864, Cat. Fish. Brit. Mus., V, 209; 
Cope, 1874, Proc. Acad. Nat. Sci. Phila., XX VI, 134, Nauta; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 678, Nauta. 
Rhinodoras prionomus Cope, 1874, Proc. Acad. Nat. Sci. Phila., XX VI, 1384, Nauta. 
Oxydoras niger Eigenmann and EKigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 247; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 393; 
Fisher, 1917, Ann. Carnegie Mus., XI, 420. 
Guianas to Rio SAo Francisco and Amazons to more than 3000 miles and 2500 
feet above its mouth. 
15651 and 15960, 4, 170-260 mm., Iquitos, Allen, 1920; Morris, 1922. 
15450, 1, 250 mm., Yarinacocha, Allen, September, 1920. 
