184 FISHES. 



Certain American species, with a round, blunt, small hear], provided 

 with cirri and almost imperceptible eyes, may constitute a new subgenus*. 

 The 



Mystus, Arted.; and Lin. in his first Editions ; 



Or tbat of the Maehoirans j, comprehends Siluri, which, in addition to 

 their first radiated dorsal, have a second that is adipose ; they are chiefly 

 the Pimelodes and the Doras of Lacepede. 



Pimelodus, Lacep. 



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

 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., 



Which have 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 de- 

 pressed head J; while in others it is broad and short §. 



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||. 



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

 kind of helmet^T. 



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

 with a naked skin**. 



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

 sides, and for an extremely small adipose fin ; these greatly resemble a 

 Schilbeff. 



Finally, there are others again which have but four cirri J J. 



Pimelodus, properly so called, 



Have nothing of the band of teeth in the vomer parallel to that in the 

 upper jaw; but teeth are frequently observed in the palate. The true 

 Pimelodes, as to the number of filaments and form of the head, present a 

 greater variety than the Bagri. 



* Sil. candira, Spix, X, 1 ; — Sil. ceecutiens, Id., lb. 2. 



t Machoiran, a name given to these fishes in the French colonies. Schneider, p. 

 478, improperly applies it to Balistes. 



X Sil. Bayad, Forsk., Porcus Bayad, Geoff., Eg., Poiss., pi. xv, f. 1 and 2; — Sil. 

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



§ Sil. erythropterus, Bl. 369, 2; — Pimel. carasius, Buchan. XI, 67; — Pirn, gulio, Id. 

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



|| Sil. lima, Bl. Schn.; — Sil.fasciatus, Bl. 366, and various new species. This divi- 

 sion forms the genus Sorubim of Spix. 



^[ Pimelode aboureal, Geoff, Eg., Poiss.. pi. xiv, f. 3 and 4; — Pimel. bilineatus, 

 Deddi-Jallnh, Russel, 169. 



** The species are new. 



tf They constitute the genus Hvpophtai.mus of Spix, of which he has two spe- 

 cies, the Hyp. edeutatus, IX, and the Hyp. nuckalis, XVII. 



XX Sil. bugre, Bl. 365; — Sil. minimis, Witch. 



