SOUTH AMERICAN NEMATOGNATHI. 333 



pressed, somewhat longer than wide except in the very 

 young. Eye slightly in front of the middle of the head. 



Barbels all long, in the adult the nasal extend beyond 

 the occiput; upper maxillary barbels extending beyond 

 the base of the pectorals. 



Gill-opening continued forward to below the eye; the 

 membrane with a free margin across the isthmus. 



Pectorals short, the first ray curved and prolonged in 

 a long filament. 



Dorsal rounded, inserted in front of the vent, its last 

 ray over the fourth anal ray in the adult, over the first 

 in the young; its origin equidistant from tip of caudal 

 and somewhere between occiput and eye. 



Caudal short, broad, rounded; its distance from the 

 anal 4J 5J in the length. 



Origin of ventrals about equidistant between tip of 

 snout and tip of caudal; their tips reaching to or beyond 

 vent. 



Color in adult: back dark brown with darker spots; 

 sides variegated with dark brown, purple and gray; fins 

 obscurely spotted. 



Color in young: yellowish, middle of sides with a 

 series of about 9, more or less confluent spots of purplish, 

 fainter spots on the tail below the median series; back 

 with about ten cross bars, 5 of which are in front of the 

 dorsal; fins plain or with dusky bars; top of head and 

 line behind eye purplish. 



Head 5-5J (5|-6 in the total); depth 6; D. 11; A. 9. 



Thirty-three specimens <3 and ? .03-. 15 m. ; Rio Para- 

 hyba; Mendez; 2 miles from Lagoa Santa; Santa Cruz 

 (Dom Pedro II). Thayer expedition. 



262. Pygidium tsenia, 



Trichomycterus tcenia Kner, "SB. Ak. Miiuch. 223, 1863"; Kiier & 

 Steindachner, Abh. Bayer. Ak. Wiss. 52, 1864, pi. vi, fig. 1. 

 (Western slope Peruvian Andes); Giiiither, Cat. Fish. Brit. Mus. 

 v, 274, 1864 (copied). 



