SOUTH AMERICAN NEMATOGNATHI. 103 



fin, or longer; mental and postmeiital barbels inserted 

 in a straight line, the mentals reaching beyond base of 

 the pectorals, the postmentals beyond their tips. 



Mouth entirely inferior, the snout projecting beyond 

 it farther than one diameter of the eye; lower jaw weak, 

 the teeth scarcely evident, in a very narrow band; the 

 teeth of the upper jaw in a somewhat wider band. 



Gill-rakers 7+17. 



Distance of dorsal fin from the snout 3J in the length; 

 first dorsal ray high and slender, scarcely spinous, the 

 free margin of the fin straight. Adipose fin beginning 

 immediately behind the dorsal, its base 2 in the length. 



Caudal deeply forked, the lobes of equal length, longer 

 than the head. 



Fourth anal ray highest, higher than the fin's base, 2 

 in the length of the head. 



Ventrals inserted little nearer to the anal than to tip 

 of the snout, 1^ in the head. 



First pectoral ray scarcely spinous, slight serrations 

 on its inner margin, about as long as the head. 



Axil and humeral region blackish, otherwise uniform 

 yellowish. 



Head 5J; depth 5|; depth of peduncle 13; Br. 9; D. 7; 

 A. 12. 



XII. PlNIRAMPUS. 



Pinirampus Bleeker, Ichth. Arch. Ind. Siluri, 198, 1858 

 (pinirampu); id. Nederl. Tijdschr. Dierkuiide, i, 100, 

 1863 (typus=pirinampu). 



Pinirampus Giinther, Cat. Fish. Brit. Mus. v, 135, 1864 

 (typus =pirinampu) . 



Type: Pimelodus pirinampu Spix. 



This genus is characterized chiefly by its barbels which 

 are broadly margined by a membrane. 



