SOUTH AMERICAN NEMATOGNATHI. 83 



Pectoral pore small; vertical series of pores present. 



Distance of dorsal fin from tip of snout 2| in the 

 length, the spine If in the head, its outer margin gran- 

 ular toothed near its base, its inner margin with short 

 teeth; distance of adipose fin from the dorsal 3^ in the 

 length. 



Adipose fin much longer than high, as long as the 

 dorsal fin. 



Caudal forked, the upper lobe one-third longer than 

 the lower, very nearly as long as the head, 3| in the 

 length. 



Anal fin emarginate, scarcely longer than high, its 

 height 2^ in the head. 



Ventrals reaching almost to the anal, about 2 in head. 



Pectoral spine a little longer than the dorsal spine, 1| 

 in the head; its outer edge roughened, inner edge with 

 rather sharp teeth. 



Brown above, the sides silvery, entire ventral surface 

 sprinkled with brown dots; a black median line on the 

 back; fins dusky; barbels blackish. 



Head 3|; depth 6i; D. I, 7; A. 20. 



4972. One specimen 3 .29 m. long. Panama. Stein- 

 dachner. 



55. Tachisurus rugispinis. 



Arius ruyispinis Cuv. & Val. Hist. Nat. Poiss. xv, 77, 1840 (Cay- 

 enne); Kuer, SB. Ak. Wien, xxvi, 1857, 388 (Para); Gtinther, 

 Cat. Fish. Brit. Mus. v, 156, 1864 (copied). 



Galeichthys rugispinis Jordan, Proc. U. S. Nat. Mus. 1886, 559 (name 

 only). 



Tachisurus rugispinis Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 

 vol. i, 1888, 145 (Para). 



Habitat: Para and northward. 



Slender, compressed on the tail. Head broad and de- 

 pressed, tapering forward; width of the head, 1|-1| in 

 its length, at the angle of the mouth 2|-2|; depth of 

 the head l|-2; profile rather steep. Top of head, hum- 

 eral process, front and sides of the spines, and dorsal 



