206 ROMANCE OF THE BEAVER 



are believed to be the ancestors of the present-day 

 species, as their fossiUsed remains have been found 

 in the pHocene deposits in which v^ere preserved the 

 skeletons of the Mastodon and Mammoth, so that 

 these animals lived during the tertiary period and 

 from the evidence which nature thus preserved 

 there is no reason to believe that the beaver, as we 

 know them to-day, differs in any marked way from 

 those of prehistoric ages. The earliest European 

 Beaver was probably the chalicomys which has been 

 found in the Miocene beds of the Continent. It 

 was considerably smaller than the existing form 

 and "" differed from all living rodents in having a 

 perforation of the lower end of the upper arm-bone 

 or humerus " (Lydekker). The largest of the 

 family was the Castoroides, whose skull was only 

 about four inches less in length than that of a lion 

 and was probably the largest of any of the rodents. 

 The beaver, both American and European, had the 

 largest range of any animal, those in Europe having 

 existed all over Europe, including Great Britain 

 (not Ireland) and Asia as far as the Euphrates. 

 During the Pleistocene period they lived in Italy as 

 far as Rome, while the American species ranged 

 all over North America from the Arctic Sea to 

 Mexico. At the present time the American beaver, 

 Castor Canadensis, is chiefly restricted to the more 

 northern portion of the Continent of North 

 America ; none are found in the region of the great 

 plains, nor in the more southerly and easterly 



