18G 



.i.v.vi/>N .\7;ii' yo/.'A' ir.i/^/;i/r or sci i:\CEfi 



1. Au^^1^ali.•ln ro^ion ^ 

 Polynesian 

 Hawaiian ' 



2. Austro-malayaii " 



?,. No()ti'o])ical 



4. ]Mala.i.'asy 



5. Ethi()i)ian " 



6. Oriental 



7. Holarctic ' 

 S. Sonoran " 



Y .\iit<i;,';ric I{cahll 



[• Xenira'ie 



> Arctoganc 



The Polynesia]! and Hawaiian regions have phiyed no material part in 

 the evolution of nianinialian faunas and do not call for a]iy special con- 

 sideration here. The limits of tlie remaining regions are shown on the 

 accompanying map. The eight principal "regions'' are l)y no means 

 equally distinct, and tlieir combination into three "realms'" does not re- 

 move this defect. Of the five included in Arctogasa, the Sonoran is 

 closest, tlie Malagasy and Ethiopian farthest removed from the central 

 Holarctic region, if we take into account both the recent and extinct 

 faunae. The true relations of the several regions might perhai)S be better 

 represented thus: 



Boreal Subregion 



Nearctic 



Palearctic 



Sonoran 

 Subregion 



Neotropical 

 Region 



Holarctic Region 



Mediterranean 

 Subregion 



Ethiopian 

 Region 



Malagasy 

 Subregion 



Oriental Region 



Austro-malayan 

 Subregion 



Australian 

 Region 



The Holarctic region in its broader sense, including the Sonoran anti 

 Mediterranean subregions. is l)ounded by the tropic of Cancer, except 

 where (as in Asia) the dispersal of the fauna from a northci'n center has 

 been hindered by east and west mountain systems, or (as in America) 

 facilitated bv north and south mountain systems. The Sonoran sub- 



