EIGENMANN: THE PYGIDIID.E, A FAMILY OF SOUTH AMERICAN CATFISHES. 299 



the first ray slightly prolonged. Origin of dorsal above posterior edge of base of 

 ventrals, equidistant from tip of caudal and nares, the last ray over origin of anal. 

 Caudal rounded, its distance from the anal 4.5 in the length. Ventrals nearer tip 

 of snout than tip of caudal. Uniform brown, darkest on the back. 



13. Pygidium vittatum (Regan). 

 Trichomycterus vittatus Regan, Ann. & Mag. Nat. Hist. (7), XII, 1903, p. G23 (Col- 

 lected by Ockenden). 

 Pygidium vittatum Eigenmann, Reports Princeton Univ. Exped. Patagonia, III, 

 1910, p. 400. 



Habitat. — Marcapata Valley, eastern Peru. 

 Known from the types, 78 mm. long, in the British Museum. 

 Head 6.25; D. 6 (branched); A. 4 (branched); head as broad as long; diameter 

 of eye 2.33 times in the interocular width, which is 3.5 in the length of the head. 

 Snout slightly shorter than the postorbital part of head. Barbels equal to eight- 

 tenths the length of head. Dorsal originating in advance of the anal opening, the 

 the distance from its point of origin to the caudal one and one-half times in the 

 distance from the former to the tip of the snout. Anal originating slightly behind 

 the vertical from the last dorsal ray, the distance from the base of its last ray to 

 the caudal four and one-half times in the total length. Longest branched ray of 

 pectoral three-fourths the length of the simple outer ray, which is as long as the 

 head. Ventrals extending six-tenths of the distance from their base to the origin 

 of the anal. Caudal truncate. Head and body with dark spots; a dark longi- 

 tudinal stripe along the middle of the side. 



14. Pygidium dispar Tschudi. (Plate XLV, fig. 5.) 

 Pygidium dispar Tschudi (partim), Faun. Peruana, Ichthyol., 1845, p. 22, pi. 3, 

 upper figure. (Eastern slope of the Peruvian Andes at an altitude of 14,000 

 ft.); Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. (2), II, 1889, p. 52 

 (Callao); Occasional Papers Cal. Acad. Sci., I, 1890, p. 335 (Callao); Proc. 

 U. S. Nat. Mus., XIV, 1891, p. 36; Pellegrin, Bull. Soc. Zool., Paris, 

 XXIX, 1904, p. 91; Starks, Proc. U. S. Nat. Mus., XXX, 1906, p. 770 (Eteri, 

 Peru) ; Poissons des Lacs des Haut Plateaux de l'Amer. Sud, 1907, p. 17 (Lake 

 Titicaca) ; Eigenmann, Reports Princeton Univ. Exped. Patagonia, III, 1910, 

 p. 400. 



Habitat. — High Andes of eastern and western Peru, down to Callao and Eteri. 



The P. dispar recorded by Ribeiro from the Rio Iporanga of southeastern 



Brazil is a different species. Tschudi says the species is abundant in the highland 



r° 



