296 PROCEEiDINGS OF THE NATIONAL MUSEUM Tor,. 94 



CHAETOSTOMA PEARSEI Elgenmann 



CORRONCHO 



Chaetostomus pearsei Eigenmann, Indiana Univ. Studies, vol. 7, No. 44, p. 8, fig. 

 3, pi. 2, 1920 (Rfo Castano at Maracay, Efo Tiiy at El Concejo, Venezuela). — 

 Peaese, Univ. Wisconsin Studies, No. 1, pp. 20, 43, 1920 (Rio Castano, 

 Venezuela) . 



CHAETOSTOMA NUDIKOSTBIS Lutken 



CAoeiostoTW MS nwJ?Vos?rzs LtJTKEN, Vid. Medd. Naturh. Foren. Kj0benhavn, 1874, 

 p. 207 (Valencia, Venezuela). — Steindachner, Denkschr. Akad. Wiss. Wion, 

 vol. 43, p. 120, pi. 5, fig. 2, 2a, 1882 (Valencia).— Regan, Trans. Zool. vSoc. 

 London, vol. 17, pt. 3, p. 251, 1904 (Valencia). — Eigenmann, Indiana Univ. 

 Studies, vol. 7, No. 44, p. 8, 1920 (no specimen secured). 



Genus PSEUDANCISTRUS Bleeker 



Pseudancistrus Bleeker, Atlas ichthyologique, vol. 2, p. 2, 1862; Ned. Tijdschr. 

 Dierk., 1863, vol. 1, p. 78. (Type, Hypostomus barbatus Cuvier and Valen- 

 ciennes.) (Ref. copied.) 



KEY TO THE SPECIES OF PSEUDANCISTRUS FROM VENEZUELA 



la. Anal rays I, 5; 3 plates from dorsal fin base to adipose origin. 



Pseudancistrus torbesensis, new species 

 16. Anal rays I, 4; 4 to 6 plates from dorsal base to adipose origin. 

 2a. Dorsal rays usually I, 6 or I, 7. 



3a. Five plates from dorsal fin base to adipose origin; 11 plates from anal 

 base to midbase of caudal fin. 



Pseudancistrus coquenani (Steindachner) 

 3&. Four p'lates from dorsal fin base to adipose origin; 9 (probably 10) plates 

 from base of anal to midbase of caudal fin. 



Pseudancistrus yaravi (Steindachner) 



26. Dorsal rays usually I, 8 or I, 9; usually 11 plates between anal base and 



midcaudal fin base; 5 or 6 plates from dorsal fin base to adipose origin. 



Pseudancistrus pediculatus cobrensis, new subspecies 



PSEUDANCISTRUS TORBESENSIS, new species 



Plate 8, C, D 



Holotype. — U.S.N.M. No. 121001, a specimen 64.6 mm. in standard 

 length, taken by Leonard P. Schultz on March 31, 1942, 1 km. above 

 T^iba in the Rio Torbes, Orinoco system. 



Paratypes.— V.S.N. M. No. 121002, 174 specimens, 15.5 to 64.6 

 mm. in standard length, taken along with the holotype and bearing 

 the same data. These types all came from swiftly running water 

 among boulders, rubble to coarse gravel. 



Description. — Based on the holotype and paratypes; detailed meas- 

 urements, expressed in hundredths of the standard length, are recorded 

 for the holotype and three paratypes, the data for the latter included 

 in parentheses, respectively. Standard length (in mm.) 64.6 (64.5; 

 51.2; 44.2; 21.5); total length 83.0 (82.0; 66.8; 59.8; 28.7) mm. 



