448 CALIFORNIA ACADEMY OF SCIENCES. 



dark spot on the base of the membrane between the dor- 

 sal spine and the first ray. 



Head 2i-2f ; D. I, 7; A. 5; Lat. 1. 24. 



Thirteen specimens .07-. 21 m. Coary; Tabatinga; 

 Jutahy. Thayer expedition. 



440. Ancistrus hoplogenys. 



Chcetoxtomus hoplogenys Gtintlier, v, 247, 1864 (Kiver Capiu, Para). 

 Ancistrus hoplogenys Eigeum. & Eigenin. Proc. Cal. Aoad. 2cl. Ser. 



ii, 48, 1889 (Tajapuru). 

 Two specimens .06-. 13 m. Tajapuru. L. Agassiz. 



441. Ancistrus temminkii. 



^ Hyposlomus iemminkli Cny. & Val. Hist. Nat. Poiss. xv, 514, 1840 



(Cayenne). 

 Ancistrus temminkii Bleeker, Silures de Suriname, 11, pi. i, fig. 3 and 



pi. ii, fig 2, 1864 (Surinam); Eigenm. & Eigeum. 1. c. (Cudajas; 



Gurupa; Lake Hyanuary; Teflfe; iQa; Eio Trombetas; Jutahy; 



Serpa; Eio Madeira; Uerauduba; Tabatinga). 

 Ancistrus dolichopterus Kner, Hypostomiden, 274, pi. iii, fig. 1, 1853 



(Barra do Rio Negro). 

 Chcetostomus dolichopterus Gtlnther, v, 249, 1864 (cojjied); Vaillant, 



Bull. Soc. Philom. series 7, iv, 155, 1880 (Calderon). 

 Habitat: Surinam; Amazons from Gurupa westward. 



Closely related to CJtcetostoTnus leucostidus Giinther, 

 from which it differs in the following characters: 



Median tentacles of the male more numerous and with 

 broader bases. Preopercular spines fewer. 



Base of the dorsal equals its distance from the middle 

 caudal rays. Caudal obliquely truncate, the outer rays 

 not produced, the lower lobe longer. 



Dark brown with indistinct darker spots; dorsal and 

 caudal uniform dusky, or sometimes with dark spots 

 smaller than those on the body; a dark spot on the base 

 of the membrane between the dorsal spine and the first 

 ray; pectoral and ventral fins dotted with light. 



Head 2|-3; D. I, 8-9 (7 in one specimen); A. 5; Lat. 

 1. 24. 



Over fifty specimens from .06-. 20 m. Cudajas; Guru- 

 pa; Lake Hyanuary; Teffe; Iga; Jutahy; Serpa; Rio Ma- 

 deira; Ueranduba; Tabatinga; Rio Trombetas. 



