168 CALIFORNIA ACADEMY OF SCIENCES. 



Pectoral spine very strong and long, scarcely shorter 

 than the rays, Ig in head; strong extrorse teeth on the 

 anterior and retrorse on the posterior edge of the spine. 



Depth of caudal peduncle 3^ in length of head. 



Color brownish marbled with darker; gill-membrane 

 broadly edged with white, in front of which is a black 

 bar; a large black spot on shoulder sometimes continued 

 across the back in front of the dorsal spine and as a 

 lateral band to the caudal; base of caudal dark brown; 

 fins dusky, spotted with darker. 



Head 3-31; depth 5; Br. 7. D. I, 6; A. 11. 



Twenty-three specimens .13-. 30 m. Tonantins; Fonte- 

 boa; Jose Fernandez; Jutahy; Xingu; Obidos; Lake 

 Hyanuary; Teffe; Villa Bella. 



121. Pimelodus ornata. 



Pimelodus ornaUoi Kner, SB. ,Ak. Wien. xxvi, 411, fig. 18, 1857 

 (Siirinam; Kio Negro; Ciijaba); Giiuther, Cat. Fish. Brit. Mus. 

 V, 116, 1864 (River Capin; Para); Peters, MB. Ak. Berlin, 470, 

 1877 (Calabozo); Eigenm. & Eigeum. Proc. Cal. Acad. 2d Ser. 

 i, 1.34, 1888 (Goyaz). 



Pseiidorhamdia ornata Bleeker, Sihires de Siiriname, 77, 1864 

 (Siiriuam). 



Silurus megacephalus Natterer in Kner, 1. c. 



Habitat: Brazilian Amazons and tributaries and the region north- 

 ward . 



Body slender, elongate. Head depressed, flat above, 

 its depth at base of occipital process 2i in its length, its 

 greatest width li; fontanel wedge-shaped, its broad end 

 above the posterior margin of the orbit; occipital pro- 

 cess comparatively slender, its width at the tip less than 

 half its greatest width which is 1^ in its length. 



Eye large, 2 in snout, li in head, 1| in interorbital. 



Maxillary barbel reaching to below adipose fin; post- 

 mentals a little beyond base of pectoral. 



Snout depressed, elongate, subspatulate, the upper jaw 

 projecting beyond the lower. Intermaxillary band of 



