134 



THE AMEBIC AN NATURALIST [Vol. XL VIII 



TABLE IIIJ 

 ,s in Various Distributions 

 I (1913 A), (1908), Grinnell t 



Antilocapridse 



Rodentia 



Sciuridaj.... 



in warm and temperate seas, and yet is composed of not 

 more than two species. No adequate explanation of these 

 exceptional cases has been offered, and it is probable that 

 their speciation, or lack of it, is due to conditions of their 

 existence or constitution which we do not understand, or 

 do not recognize. 



