122, MUSTELID ®. 
Whatever revolutions the surface of this island has sub- 
sequently undergone, the Otter, as a species, still survives. 
The Beaver was its associate in the ancient rivers of Eng- 
land, from the pliocene era down to the historical period, 
when this large herbivorous rodent finally disappeared, ac- 
cording to some Naturalists, in the year 1188. The 
intimate dependence of the Beaver upon the bark of trees 
for food, and upon the wood for the fabrication of its dams 
and dwelling-place, makes its extirpation a very obvious . 
consequence of the clearance of the forests of England. 
The Otter, independent of the vegetation which, of yore, 
overshadowed the rivers which it haunted, burrowing in 
their banks for shelter and concealment and preying ex- 
clusively on their scaly inhabitants, has been comparatively 
little affected by the changes which cultivation has pro- 
duced in the lands through which those streams now flow. 
Fig. 44, 
Lower jaw. 
Upper jaw. an 
Otter, nat. size, Fens, Cambridgeshire. 
