84 NORTH A:\[ERI('AN fauna. Fno-IG. 



for the soiitlieru Cascudes aud 7 lor the northern Sierra. ( )f these 

 distinctive specific types only 3 of the 7 Sierra species fail to reach 

 Shasta, Avhile all of the 8 Cascade species fail. 



The signiticance of these tacts appears when the lioreal faunas of 

 the mountains north aud south of Klamath (lap are studied with ref- 

 erence to their geographic sources of origin, as pointed out in the next 

 chapter. 



