194 FISHES OF WESTERN SOUTH AMERICA 
Uniform dark brown or indications of marbling, dorsal membranes translucent, 
the rays alternately light and dark; caudal in the young with three dark bars, the 
bars more numerous and less regular in the old, the membranes always translucent, 
the angles of the fins sometimes very narrowly rusty; anal, ventrals and pectorals 
uniform or the ventral rays alone with faint spots. 
183. CHAETOSTOMA SERICEA Cope 
Chaetostomus sericeus Cope, 1871, Proc. Acad. Nat. Sci. Phila., 288; 
Eigenmann and Eigenmann, 1889, Proc. Cal. Acad. Sei., (2), H, 46; 
Eigenmann and Eigenmann, 1890, Oce. Papers Cal. Acad. Sci., I, 448. 
Xenocara sericea Regan, 1904, Trans. Zool. Soc. London, X VIT, 252. 
Rio Ambyiacu 
184. CHAETOSTOMA VARIOLA Cope 
Chaetostomus variolus Cope, 1871, Proc. Acad. Nat. Sci. Phila., 288; 
Bigenmann and Eigenmann, 1889, Proc. Cal. Acad. Sei., (2), I, 46; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sei., I, 442. 
Xenocara cirrhosa (in part) Regan, 1904, Trans. Zool. Soc. London, XVII, 256. 
Ancistrus cirrhosus Kigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 411. 
Rio Ambyiacu 
185. CHAETOSTOMA BRANICKIL Steindachner 
Chaetostomus branickit Steindachner, 1881, Denksch. KIX. Akad. Wiss. Wien, XLIII, 118, pl. vi, 
fig. 1, one, 110 mm., R. Huambo; 
Eigenmann and Bigenmann, 1889, Proc. Cal. Acad. Sci., (2), II, 46; 
EKigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 443; 
Regan, 1904, Trans. Zool. Soc. London, XVII, 250; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 410. 
Rio de Huambo; Callacate, Peru, specimens reaching 135 mm. 
186. CHAETOSTOMA DERMORHYNCHA Boulenger 
Chaetostomus dermorhynchus Boulenger, 1887, Proc. Zool. Soe. London, 277, pl. xxii, Canelos; 
Eigenmann and Eigenmann, 1889, Proc. Cal. Acad. Sci., (2), H, 46; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sei., I, 443; 
Regan, 1904, Trans. Zool. Soc. London, XVII, 248; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 410. 
Canelos, Ecuador, the types alone being known 
187. CHAETOSTOMA LOBORHYNCHA Tschudi 
Chaetostomus loborhynchus Tschudi, 1845, Fauna Peru., 26, pl. iv; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 250; 
Eigenmann and Eigenmann, 1889, Proc. Cal. Acad. Sci., (2), I, 46; 
