SOUTH AMERICAN NEMATOGNATHI. 243 



or four above the median hook. Caudal peduncle with 

 a single plate above and another below; back and belly 

 naked. 



Humeral process greatly swollen in front, tapering, 

 reaching to the first or second median scute; its surface 

 sharply granular, with a series of recurved hooks near 

 its lower margin. 



Distance of the dorsal spine from the snout 2-f 2 in 

 the length. Dorsal spine straight, about as high as its 

 distance from the anterior margin of the eye; its pos- 

 terior margin smooth, its sides each with two high 

 ridges, its anterior margin with upturned seme. Dis- 

 tance of the adipose fin from the dorsal fin 3|-4J in 

 the length, its base shorter than that of the dorsal fin. 



Caudal scarcely emarginate. Anal rounded, the mid- 

 dle rays highest, 1| in the head. 



Ventrals not reaching the anal. 



Pectoral spine reaching past base of ventrals, its 

 sides striate, its margins serrate. Pectoral pore incon- 

 spicuous, simple. 



Sides and back marbled with dark and light brown; 

 ventral surface dusky, all the fins with bars or round 

 dark spots. 



Head 4; depth about 5; D. I, 6; A. 11-12; V. 7; P. I, 7; 

 Lat. 1. 24-25. 



Ten specimens .05-. 11 in. long. Jutahy; Teffe; Porto 

 do Moz; Serpa. Prof. Agassiz; Thayer; Senhor Vinhas. 



182, Doras heckelii. 



Dora* heckelii Kner, SB. Ak. Wieu, xvii, 125, fig. 4, 1855 (Rio 

 Negro); Giinther, Cat. Fish. Brit. Mus. v, 204, 1864 (copied); 

 Eigenm. &Eigenm. Proc. Cal. Acad.2d Ser. i, 163, 1888 (Jutahy; 

 Tenanting; Teffe; Tabatinga). 



Habitat: Solimoens. 



Body heavy forward tapering to a slender caudal 

 peduncle; the depth below the dorsal spine f of the 

 width; the depth at the caudal peduncle greater than 



