108 INTRODUCTION. 



shores ; they being nearly as abundant in some parts 

 of Canada as in the United States. 



Leaving out of consideration the ocean, which of 

 course confines whole tribes and orders of animals 

 ■within one area, it would seem necessarily to result, from 

 the preceding facts and observations, that merely geo- 

 grajthical features do not much affect the distribution of 

 species ; and that their territorial range, under simi- 

 lar and favorable conditions, is, irrespective of geo- 

 graphical limits, very wide. The vast area between the 

 Rocky Mountains and the Atlantic Ocean may, for 

 these animals, be considered as one zoological district ; 

 and it may be assumed that they are diffused through- 

 out the whole of it, except where they are restrained by 

 climate, or by other general or local causes. 



The followinGT tabular view exhibits the distribution 

 of the species mentioned in this work, according to 

 the geographical divisions before defined, so far as un- 

 derstood at this time. The species believed to have 

 been introduced from other countries are printed in 

 italic letters. 



