404 ORDER MALACOPTERYGII ABDOMINALES. 



Some are remarked for a depressed head, eyes 

 situated very low on its sides, and an extremely 

 small adipose dorsal. They very much resemble 

 Schilbe ! . 



Finally, there are Bagri, which have but four 

 barbels 2 . 



Pimelodus (properly so called), 



Have no band of teeth at the vomer parallel to that 

 of the upper jaw, but there are frequently some in 

 the palatines. These fishes exhibit, in the number 

 of their threads, and in the forms of their head, 

 varieties yet more numerous than those of the 

 bagri. 



Thus, among those which have but a single band 

 of teeth, some are observed to have the head helmeted, 

 and a distinct osseous plate, or buckler, between the 

 helmet and the spine of the dorsal 3 . 



Others, in which the buckler is united to, and forms 

 but a single body, with the helmet, which thus 

 extends from the muzzle as far as the dorsal 4 . 



There are others, in fine, which have the head 

 oval, invested solely by the skin, through which the 



1 Spix forms of these his genus Hypophthalmus, of which there 

 are two species : Hyp. edentatus. ix. ; Hyp. nuchalis, xvii. 



2 Sil. bagre, Bl. 3G.5. Sil. rnarinus, Mitch. 



3 Sil. clarias, Bl. XXXV. i. 2. Pimel. maculatus, Lacep. v. p. 

 103. Sil. hemiolioplerus, Bl., Schn. 



4 New species. 



