190 MEMOIRS OF THE CARNEGIE MUSEUM 



60. Oxydoras niger (Valenciennes). 

 Doras niger Valenciennes, in Humboldt, Rec. Obs. Zool., II, 1811, 184. — Cuvier 

 and Valenciennes, Hist. Nat. Poiss., XV, 1840, 291 (?). — Schomburgk, Fishes 

 Brit. Guiana, I, 1841, 165. — Muller and Troschel, in Schomburgk, Reisen, 



III, 1848, 629 (Rivers of Guiana).— Bleeker, Nederl. Tijdschr. Dierk., I, 

 1863, 14 (name only). 



Rhinodoras niger GiJNTHER, Catalogue, V, 1864, 209 (Amazons). — Cope, Proc. Am. 

 Philos. Soc, XVII, 1878, 678 (Nauta) .— Vaillant, Bull. Soc. Philom., (7), 



IV, 1880, 14 (Calderon). 



Oxydoras niger Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., (2), I, 1888, 



159 (Teffe; Gurupa; Manacapuru; Coary; Obidos); Occasional Papers Cal. 



Acad. Sci., I, 1890, 247.— Kindle, Ann. N. Y. Acad. Sci., VIII, 1894, 251 



(Pard). — Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 393. 

 Doras humboldti Agas&iz, Selecta Gen. et Spec. Pise. Bras., 1829, 129, pi. 5 (Rio San 



Francisco, Brazil). — Agassiz, a Journey in Brazil, 1868, — . 

 Corydoras edentatus Spix, Selecta Gen. et Spec. Pise. Bras., 1829, pi. 5. 

 Rhinodoras prionomus Cope, Proc. Acad. Nat. Sci. Phila., 1874, 134 (Nauta); 



Proc. Am. Philos. Soc, XVII, 1878, 678 (Nauta). 

 /^/imodoms ie^eanws Steindachner, SB. Akad. Wiss. Wien, LXXI, 1875, 145, pi. 3 



(Teffe). 



One specimen, 178 mm. Rupununi. (C. M. Cat. No. 1622.) 



Head 3.3; depth 4.5; D. 1,6; A. 11; lateral plates 23; eye 3 in interorbital, 

 4 in snout, 3 in preorbital part of head. 



Deepest in front of dorsal spine, the depth equal to the width ; caudal peduncle 

 depressed, its depth half the distance from anal to lower caudal rays. Head 

 pointed, its width 1.4 in its length, almost equal to its depth. Opercle, top of 

 head, and dorsal plate tubercular striate. Interorbital flat; fontanel narrow, in a 

 wide groove continued beyond the fontanel, which does not extend beyond the 

 middle of the eye. 



Lips and barbels thickly papillose, the barbels simple, free from the lips and 

 not united; maxillary barbel extending a little beyond eye; distance between nares 

 less than their distance from tip of snout or eye; distance between gill-openings 

 equals width of mouth. Highest lateral scute less than one-fourth the length of 

 the head, each scute with a veiy strong median hook, up to eight spines below the 

 median hook and up to ten above it. 



Dorsal spine striate, with a few straight spines on its posterior surface and 

 much more numerous and stronger antrorse hooks on its anterior margin. Pectoral 



