SOUTH AMERICAN NEMATOGNATHI. 281 



length; adipose fin rather large, its anterior margin con- 

 tinuous with the profile of the back. 



Caudal obliquely truncated, the longest rays about 5 

 in the length. Anal fin comparatively short, its free 

 margin either straight or emarginate in front, always 

 strongly convex behind. 



Ventrals short and broad, reaching the anal, about If 

 in the head. 



Pectoral spine very strong, of varying length, some- 

 times reaching half way to the base of the ventrals, some- 

 times half way to the anal, 4-5 in the length. First pec- 

 toral ray about as long as the spine. 



Color variable; sometimes light brown with dark spots 

 on the dorsal, caudal and pectoral, the anal and ventrals 

 white. Sometimes darker brown, mottled with darker, 

 and all the fins profusely spotted; ventral surface thick- 

 ly covered with brown or black dots. 



Head4J-4f; depth 3-4|; D. I, 6; A. 22-24, rarely 25; 

 V. 6; P. I, 7. 



Specimens .065-.22 m. Pernambuco; San Gongallo; 

 Rio San Francisco, below the falls; Tabatinga; Teffe; Rio 

 Puty. 



223, Trachycorystes robustus. 



Auchempturus robustus Giinther, Cat. Fish. Brit. Mus. v, 197, 1864 



(Demarara). 

 Trachycorystes robustus Eigenm. & Eigenm. Proc. Cal. Acad. 2d 



Ser. i, 156, 1888 (name only). 

 Habitat: Demarara. 



This species is known only from the types. 



224, Trachycorystes analis, 



Trachycoryxtes a?ia^'sEigeum. & Eigeurn. Proc. Cal. Acad. 2d Ser. i, 

 156, 1888 (? Arary). 



Width of the head equal to its length; width of the 

 mouth If in length of head; the depth at the occipital 

 process 1| in the length of the head. Fontanel oval, sur- 

 rounded by bone. 



