SUPPLEMENT 



ON THE 



FOURTH ORDER OF FISHES. 



MALACOPTERYGII APODES. 



In the great genus Mur^ENA we shall commence by treating 

 of that subdivision, Anguilla, to which our common eel 

 belongs ; and to this last shall our principal attention be 

 confined. 



There are several species of the subgenus Anguilla, of 

 which the common eel alone lives exclusively in the fresh 

 water ; the others, comparatively speaking, but imperfectly 

 known, frequent the mouths of rivers, into the streams of 

 which they ascend in summer. 



The common eel, which sometimes has been termed water 

 serpent, in consequence of its elongated cylindrical form, 

 similar to that of snakes, varies frequently enough in its 

 colours. It appears, according to the report of Spallanzani, 

 that the shades of these colours depend materially on the age 

 of the animal and the quality of the water in the midst of 

 which the animal may live. In muddy waters the eel is 

 brown above and yellowish underneath ; in limpid waters it 

 is of a varying green, striped with brown above, and of a 

 silvery white underneath. Its anal fin is edged with white, 

 and the dorsal with red. 



