204 



A TRANSITION-FORM. 



many land-drains, the water of which continues to run 

 in its course over the mud into the channel during the 

 whole time the tide is out. In Somersetshire, as Mr. 

 Yarrell remarks, the people know how to find the holes 

 in the river-banks in which the eels are hybernating, by 

 the hoar-frost not lying over them as it does elsewhere, 

 and they dig them out in heaps. 



The eel seems to form a connecting link between the 

 fish and serpent, and probably the abhorrence with which 

 it is regarded by the Jews is due to its serpentine form. 



It has no ventral fins, and its body is covered with a soft, 

 thick, viscous skin, of which the scales are so minute as 

 to be almost invisible, whilst they are sometimes wanting. 

 It belongs to the family or order Murcenidce, which 

 some naturalists subdivide, according to their characteris- 

 tics, into the families Synbranckidce, Murcenidce , Anguil- 

 lidce, CongeridcKj and Opkisuridce. In all these the ske- 

 leton is without ribs, and the fin-rays are not articulated ; 

 two features distinguishing them from the Gymnotidce, or 



