THE SILLRINiE, OR EEL SILURES. 



549 



we see in the genera Mormyrus, Chironectes, Uranosco- 

 pus, Trachinus, and numerous others. So completely, 

 indeed, do these Silurinee remind the ichthyologist of 

 the chironectiform type, that Dr. Riippell has given the 

 specific name of Uranoscopus to a species he has recently 

 discovered in -the Nile. This testimony of its analo- 

 gical relation to the order Plectognathes is highly satis- 

 factory, since it is given, as it were, incidentally, or as 

 an insulated fact, without any idea of the inference we 

 have drawn from it. 



(285.) We now pass on to the fourth division or 

 genus of the Silurinee, to which we retain the name of 

 Plotosus Bloch. With but one exception * (Heterobran- 

 chus bidorsalis Geoff., fig, 87.), all the fishes it contains 



87 ^-^^ 



have but a single dorsal ; but then this fin, instead oi 

 being short and high, is very long and low, — so long, 

 indeed, that it extends to nearly the whole length of the 

 back ; the anal fin is nearly of the same length ; and 

 both either terminate just before they reach the caudal, 



as in the sub-genus Clarias (fig. 88.), or are actually 

 united to that fin, as in Plotosus (fig. 'J Q.),theb.eaid is still 



* M. Cuvier has placed under Heterobranchus, certain fishes belonging to 

 the genus Clarius of Gronovius, which was subsequently called Macropte- 

 ronotus by Lacepede. As, I consider these latter to belong to a distinct 

 type, they are so designated in the Synopsis, under the original name of 

 Clarias, imposed on them by Gronovius, which I see no occasion for alter- 

 ing. If these fishes have the same ramified branchia as Geoffroy's Hetero- 

 branchus bidorsalis, an additional sanction is given for placing the latter 

 fish in the genus Plotosus, notwithstanding its possessing two dorsal fins. 

 I must confess, however, that I am not quite satisfied on the true relations 

 of this singular type. 



