CHAPTER IX. 



THE HOLARCTIC REGION. 



Characteristics of the Mammalian Fauna Mammals of the Eastern Holarctic 

 Region Plistocene Fauna of the Holarctic Region Geographical Changes 

 since the Plistocene Western Division of the Region Arctic Sub -region 

 European Sub-region Central Asian Sub-region Tibetan Sub-region 

 Mantchurian Sub-region Mediterranean Sub-region Kashmir Ca- 

 nadian Sub-region Transition Zone. 



BY far the most extensive of all the zoological regions of the 

 globe is that which is equivalent to the whole of the Palsearctic 

 and the greater portion of the Nearctic region of Messrs Sclater 

 and Wallace, the one to which Dr Heilprin (after a suggestion 

 of Professor A. Newton) applied the name Holarctic. In defining 

 this region, Dr Heilprin separated from it a Sonoran "transitional 

 region " in the Western Hemisphere, and a similar Mediterranean 

 or Tyrrhenian tract in the Eastern. Of these the former is 

 now accepted as a definite region ; but our knowledge of the 

 distribution of species in the Eastern Hemisphere is either too 

 imperfect, or the interdigitation of the two faunas is too complete 

 to admit of the full definition of a Mediterranean region. Accord- 

 ingly, without prejudice as to what it may be possible to ac- 

 complish in this direction in the future, the Mediterranean area 

 is provisionally included in the Holarctic region. It is, however, 

 important to observe that the reservation by Dr Heilprin of the 

 two transitional tracts already named justifies the use of the term 

 Holarctic even if both such tracts be raised to the rank of separate 

 regions ; and there is accordingly no necessity for the adoption of 

 Dr Blanford's term Aquilonian as equivalent to the restricted 

 Holarctic. Used in the sense here indicated, the Holarctic region 

 will comprise all that portion of Arctogasa lying north of the 



