The gymnoti, like our eels, are fond of swal- 

 lowing and breathing air on the surface of the 

 water ; but we must not thence conclude with 

 Mr. Bajon, that the fish would perish, if it could 

 not come up to breathe the air. Our eels wan- 

 der a part of the night upon the grass, while 

 I have seen a very vigorous gymnotus, that 

 had sprung out of the tub, die on the ground. 

 Mr. Provencal and myself have proved, by our 

 researches ori the respiration of fishes, that 

 their humid bronchiae can execute the double 

 function of decomposing the atmospheric air, 

 and of appropriating the oxygen dissolved in 

 water. They do not suspend their respiration 



torpedo narke Risso, t. unimaculata, t. marmorata, t.galvanii, 

 silurus electricus, tetraodon electricus, gymnotus electricus. 

 It appears uncertain, whether the trichiurus indicus have 

 electrical properties or not (Cuv. Re gne animal, vol. ii, p. 247). 

 But the genus torpedo, very different from that of the rays 

 properly so called, has numerous species in the equatorial 

 seas ; and it is probable, that there exist several gymnoti 

 specifically different. The Indians mentioned to us a very 

 black and very powerful species, inhabiting the marshes of 

 the A pure, which never attains a length of more than two 

 feet, but which we were not able to procure. The ratun of 

 the Rio de la Magdalena, which I have described under the 

 name of gymnotus aequilabiatus ( Observ. de Zoologie, vol. i, 

 pi. x, fig. 1), forms a particular subgenus. This is a carapa, 

 not scaly, and without an electrical organ. This organ is 

 also entirely wanting in the Brazilian carapo, and in all the 

 rays, which Mr. Cuvier has had the goodness to examine 

 again at my request. 



