Annals Entomological Society of America [Vol. XII, 



As a result of these studies, I have come to believe that 

 though the West Coast fauna is to a degree complex, it is yet 

 made up of a definite number of elements which can be distinctly 

 separated. The insect fauna as we now know it, has been 

 derived from older faunas and these were either northern or 

 southern in their origin. Each of these primary portions was 

 in its turn composed of elements which had come into their 

 present territory at different times and along different roads. 

 Certain of these had remained pure and are at present restricted 

 to definite areas, while others had either wholly or partially 

 invaded regions already occupied by other elements and become 

 mixed with them. These facts are of course in general in 



litt. of Korthsait 

 ■softly Canadian^ 



-< Vancouveren 



Bierran 



Callfomian 



Oreat Basin 



Sonoran 



Fig. 1. Map showing the Faunal Areas of the Pacific States of North America. 



