334 CALIFORNIA ACADEMY OF SCIENCES. 



Pygidium tcenia Eigenm. & Eigenm. Proc. Cal. Acad. Sci.2d Ser. ii, 



51, 1889. 

 Habitat: Western slopes of the Peruvian Andes. 



263. Pygidium laticeps. 



Trichomycterus laticeps Kner, "1. c.;" Kuer & Steindachiier, 1. c. 



54, pi. vi, fig. 2 and fig. la. (Western slope Peruvian Andes.) 

 Pygidium laticeps Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. 



ii, 51, 1889. 

 Habitat: Western slopes of the Peruvian Andes. 



264. Pygidium oroyae, 



Pygidium oroyce Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. 



ii, 51, 1889 (Oroya). 

 Types, No. 3955; eight specimens; .115-. 14 m. Pochachara, Oroya 



Kiver. 



This species is very closely allied to P. brasiliensis. 



Rather robust; head about as long as wide; none of 

 the barbels reaching the gill-opening. Gill-membrane 

 narrowly joined to the isthmus, without a free margin. 



Pectoral short, fan-shaped, the first ray not prolonged. 



Dorsal inserted over the vent, its last ray over or be- 

 hind the middle of the anal, its origin equidistant from 

 anterior margin of eye or occiput and tip of caudal. 



Caudal broadly rounded, its distance from the anal 

 4-4| in the length. 



Origin of ventrals about midway between tip of snout 

 and tip of caudal. 



Dark chocolate brown; sides, back and unpaired fins 

 with irrregular groups of dark points. 



Head5|-6; depth 5f-7; D. 12; A. 10. 



265. Pygidium punctatissimum. 



Trichomycterus punctatissimus Castelnau, Aiiirn. Am. Slid, 49, pi. 



24, fig. 3, 1855 (Araguay). 

 Pygidium punctatissimum E. & E. Proc. Cal. Acad. 2d Ser. ii, 52, 



1889. 

 Habi tat : Araguay . 



