SOUTH AMERICAN NEMATOGNATHI. 245 



wards and reaching the last third of the pectoral spine; 

 its surface with series of sharp granules and a series of 

 larger hooks near its lower margin which are reduced to 

 a pectinate ridge in the adult. 



Distance of the dorsal spine from the snout 2J in the 

 length; dorsal spine longer than the head, its sides 

 deeply furrowed, its anterior margin with upturned 

 serrse, its posterior margin broad, smooth, having a 

 median groove. First dorsal ray higher than the spine, 

 nearly reaching the adipose fin. Distance of the adi- 

 pose fin from the dorsal fin 3f 4f- in the length, its base 

 about as long as that of the dorsal fin. 



Caudal fin emarginate, having conspicuous accessory 

 rays. 



Anal fin higher than long, rounded; its middle rays 

 1J in the head. Ventrals about as high as the anal. 



Pectoral spine long and curved, reaching to the vent, 

 little beyond the base of the ventrals in the adult; its 

 upper surface coarsely its lower surface finely striate, 

 both margins with strong teeth. Pectoral pore simple, 

 above the base of the pectoral. 



Sides and back chocolate, dotted and spotted with 

 darker. Lower surface white, belly densely and other 

 portions more sparsely covered with brown dots. Fins 

 all more or less spotted with brown. 



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

 P. I, 7; Lat. 1. 29-30. 



One specimen .16 m. Jutahy. James, Thayer & Tal- 

 isman. Two specimens .11-. 13 m. Tonantins. Thayer 

 <fe Bourget. Twelve specimens .05-. 18 in. Teffe. Prof. 

 Agassiz. Two specimens. Tabatinga. Bourget. 



183, Doras monitor. 



Zalhorax monitor Cope, Proc. Acad. Nat. Sci. Phila. 1872, 271, pi. 



4, fig. 1 (Amazon). 

 Habitat: Amazon. 



This species is known only from the types. 



