300 MEMOIRS OF THE CARNEGIE MUSEUM. 



between the two chains of the Cordilleras, but on the eastern slope only. It is 

 quite possible that Tschudi had two species and that the unspotted male he figured 

 is the taczanowskii of Steindachner. The specimens recorded by Pellegrin are 

 probably P. rivulalum. 



Head 5.2; D. 12; A. 9. Elongate, compressed, the depth everywhere less than 

 the length of the head. Head longer than wide by more than a diameter of the eye. 

 Eye moderate, four times in the interocular, equidistant from tip of snout and end of 

 opercle. None of the barbels reaching quite to the gill-opening. Gill-openings 

 continued forward to below the eye. Pectorals obliquely rounded, the first ray 

 produced in a filament. Origin of dorsal equidistant from tip of caudal and anterior 

 margin of the eye, the whole fin in front of the anal and behind the ventral fins. 

 Caudal emarginate. Distance of anal from base of caudal six times in the length. 

 Origin of ventrals midway between tip of snout and tip of caudal. 



Reddish brown; sides, back, dorsal and caudal fins with large dark spots, 

 those on the head smallest; lower surface plain. 



15. Pygidium punctulatum (Cuvier & Valenciennes). (Plate XLV, fig. 4.) 

 Trichomycterus pnncfulatus Cuvier & Valenciennes, Hist. Nat. Poiss., XVIII, 



1846, p. 488 (Lima); Lutken, Velhas Flodens Fiske, 1875, p. 137 (Callao). 

 Pygidium dispar punctulatum Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. 



(2), II, 1889, p. 52 (Rio Remac, near Lima); Occasional Papers Cal. Acad. 



Sci., I, 1890, p. 336 (Rio Remac, largest 180 mm.); Proc. U. S. Nat. Mus., 



XIV, 1890, p. 36. 

 Pygidium punctulatum Starks, Proc. U. S. Nat." Mus., XXX, 1906, p. 771 (Callao); 



Eigenmann, Reports Princeton Univ. Exped. Patagonia, III, 1910, p. 400. 

 TrichoynyctcruH punctatus Cuvier & Valenciennes, I. c, pi. 552. 



Habitat. — Rio Remac, Peru. 

 4234, I. U. M., one, 145 mm., a female with emi)ty ovary. Callao. 



From the Harvard collections. 



Head 5.33-5.66; D. 12; A. 10. 



Teeth conic, in about five series in the middle of the jaws. 



Origin of dorsal equidistant from tip of caudal and somewhere between occiput 

 and anterior margin of eye; distance of anal from base of caudal 6-6.5 in the length. 



16. Pygidium taczanowskii (Steindachner). (Plate XLVI, figs. 5-8.) 

 fPygidium dispar Tschudi (in part), Fauna Peruana Ichthj'ol., p. 22, pi. 3 (lower 



figure). 

 Trichomycterus taczanowskii Steindachner, Flussf. Siidam., IV, 1882, p. 22, pi. 



IV, figs. 1-16 (Rio de Huambo; Rio de Tortora). 



