SOUTH AMERICAN NEMATOGNATHI. 293 



ending in a sharp point behind. Barbels 6; gill-mem- 

 brane joined to the isthmus. Humeral process present. 



231, Epapterus dispilurus. 



Epapterus diapilurus Cope, Am.Philos. Soc. xvii, 1878, 677 (Peruvian 

 Amazon); Steindachner, Flussfische Siidamerikas, iv, 31, 1882 

 (Hyavary); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 152, 

 1888 (Hyavary). 



Evanemus longipinnis (Agassiz) Steindachner, Flussfische Siidameri- 

 kas, iii, 17, 1881 (Hyavara). 



Habitat: Upper Amazons. 



Elongate, strongly compressed; ventral outline almost 

 straight, dorsal outline gently arched. Head short, its 

 greatest depth a little less than its greatest width, which 

 is 1| in its length; surface of the bones roughened, cov- 

 ered with thin skin. Frontal fontanel continued to the 

 occipital. Occipital process more than twice as broad 

 as long, rounded behind and joined to the dorsal plate. 

 Sides and anterior edge of dorsal plate emarginate, 

 widely forked behind; the forks projecting far beyond 

 the dorsal fin, and longer than the rest of the plate. 



Eye large, lateral, 1 in snout, 3 in head, 1J in inter- 

 ocular. 



Barbels reaching to beginning of ventrals; jaws sub- 

 ^equal, width of mouth 1J in width of head at the rictus. 



Gill-rakers long and slender, 13+23. Pectoral pore 

 present. Lateral line zig-zag, with numerous branches. 



Distance of dorsal fin from snout 5 in the length; the 

 spine little longer than the pupil. 



Caudal fin emarginate, 5 in the length. 



Anal fin very long, the distance of its origin from 

 snout 2| in the length. 



Ventrals reaching far beyond origin of anal, one- 

 fourth longer than head. 



Pectoral spine strong, reaching ventral fins, its sides 

 and outer margin smooth, its inner margin serrate, 1J 

 in head. 



