MALACOPTERYGII ABDOMINALES. 215 



Mystus, Arted.; and Lin., Ed. I. 



Or that of the Machoirans,(l) comprehends Silui-i, which, in ad- 

 dition to their first radiated dorsal, have a second that is adiposej 

 they are chiefly the Pimelodes and the Doras of Lacepede. 



PiMELODus, Lacep. 



The body merely covered with a naked skin; no lateral armature. 

 This subgenus is still much too numerous, and its species differ so 

 widely in conformation, that we have been compelled to divide and 

 subdivide it. We first distinguish the 



Bagrus, Cuv. 



A band of small crowded teeth in each jaw and behind that of the 

 upper one, a similar band on the vomer; they may be subdivided 

 by the number of cirri and the form of the head. 



Among those which have eight cirri, some have an oblong and 

 depressed head;(2) while in others it is broad and short.(3) 



Of such as have six cirri, the most remarkable are those with a 

 snout as depressed and broad as that of a Pike, and more so. (4) 



Some have an oval head, whose shagreen-like bones furnish it 

 with a kind of helmet.(5) 



The head of others is round, without the helmet, and merely co- 

 vered with a naked skin. (6) 



Some are remarkable for a depressed head, eyes placed very low 

 on its sides, and for an extremely small adipose fin; these greatly re- 

 semble a Schilbe.(7) 



Finally, there are others again which have but four cirri. (8) 



(1) Machoiran, a name given to these fishes in the French colonies. Schnei- 

 der, p. 478, improperly applies it to Balistes. 



(2) Sil. Bayard., Forsk., Forms Bayard., Geoff., Eg., Poiss., pi. xv, f. 1 and 

 2; — Sil. Docmac, Forsk., Geoff., lb., 3, 4? — Pimelodus aor., Buchan., XX, 68? 



(3) Sil. erythropterus, Bl., 369, 2; — Pimel. carasius, Buchan., XI, 67; — Pirn, 

 gulio. Id., XXIII, 66; — Pirn, carcio. Id., I, 72; — Pirn, nangra. Id., XI, 63. 



(4) Sil. lima, Bl. Schn.; — Sil. fasciatus, Bl. 366, and various new species. This 

 division forms the genus Souubim of Spix. 



(5) Pimelode ahour^al, Geoff., Eg., Poiss., pi. xiv, f 3 and 4; — Pimel. bilineatus, 

 Deddi-JaUah, Russel, 169. 



(6) The species are new. 



(7) They constitute the genus HyropiiTALMtis of Spix, of which he has two spe- 

 cies, the Hyp. edenlatus, IX, and tiie Hyp. nuchalis, XVII. 



^8) Sil. bagre, Bl. 365; — Sil. rnarimts, Mitch. 



