298 MEMOIRS OF THE CARNEGIE MUSEUM. 



6; D. 9; A. 7; eye in micklle of the head; head a little longer than wide; nasal barbels 

 reaching lateral end of head, maxillary barbel a little beyond origin of pectoral. 



20. fassli Steindachner. 

 aa. Pectoral ray not prolonged; end of dorsal about over the middle of the anal; caudal rounded; head as 

 long as wide; sides and back with irregular spots. 

 h. Eye moderate; origin of the dorsal over or in front of the vent, equidistant from eye and tip of 



caudal or nearer the latter; head 5.75-6; D. 12; A. 10 21. oroyae Eigenmann. 



hh. Eyes very minute; origin of the dorsal in front of the vent, nearer the eye than the tip of the 

 caudal; head 5; D. 8; A. 6 or 7 not counting the liidden rays; a dark lateral line. 



22. quechuorum Steindachner. 



11. Pygidium fuscum Meyen. 

 Pygidium fuscum Meyen, Reise, I, 1835, p. 475; Wicgmann's Arch., 1835, II, p. 

 269; Eigenmann & Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, 

 p. 325; Proc. U. S. Nat. Mus., XIV, 1891, p. 36; Eigenmann, Reports Prince- 

 ton Univ. Exped. Patagonia, III, 1910, p. 399. 

 Habitat. — Peru. 



Very little is known about this species. It was imperfectly described by Meyen. 

 Fortunately the type which was found dead in some stream in Peru, is in the Berlin 

 Museum {fide Tschudi, Fauna Peruana, Ichthyologie, 1845, p. 21). Tschudi 

 tells us that fuscum is specifically distinct from his own species dispar. This and 

 the original description is all we know about the species. 



12. Pygidium eigenmanni (Boulenger). 

 Pygidium knerii Eigenmann & Eigenmann (won Steindachner), Occasional Papers 



Cal. Acad. Sci., I, 1890, p. 335 (Cumbaca). 

 Trichomycterus eigenmanni Boulenger, Boll. Mus. Zool. Anat. Comp. Univ. 



Torino, XIII, Dec. 2, 1898, substituted for P. knerii Eigenmann & Eigenmann, 



non Steindachner. 

 Pygidium eigenmanni Eigenmann, Reports Princeton Univ. Exped. Patagonia, 



III, 1910, p. 400. 



Habitat. — Cumbaca. Location on map not known. 



Boulenger based his eigenmanni on the description of P. knerii Eigenmann & 

 Eigenmann, which, according to Boulenger, was based on a specimen distinct from 

 knerii. The species is known from the description of a specimen 1 10 mm. long from 

 Cumbaca, collected by the Thayer Expedition and now at Cambridge, Mass. 



Head 5; depth 5.66; D. 10; A. 9. Elongate, compressed; head greatly de- 

 pressed, flat above, the eyes entirely superior; width of the head less than its length. 

 Barbels scarcely extending beyond the eyes, which arc equidistant from tip of snout 

 and end of opercle. A broad band of villiform teeth in each jaw. Pectoral rounded, 



