ZOOGECliAPHY 



short of the regional boundaries in c (ain directions. Many spe 

 even have an extensive range in twor more areas. Thus liana 

 the common leopard frog, occurs ij general over all of North 

 east of the Sierra Nevada Range; an t he raccoon, Procyon lotor, f 

 the deciduous forests of eastern Unit( States and the prairie-plaii 

 as well. If all animals showed as ttle relation to natural ve 

 areas as do these two, the major evironments mentioned abo^ 

 probably never have been recogniid. Without pursuing thi; 

 formity any further it may be said lat there are two classes of 

 which frequently ignore the major r \ironments; first, terrestri 



O F 



M 



E XT C O 



:4 



-Range of Thamnophis aauriius sackr { Kenn.), the southeastern ribV 



(After Rutin.) 



tolerant of a wide range of ccditions, and, second, moi 

 ^rms. The leopard frog pronbly owes its general dist 

 ^ts semi-aquatic habits, and he raccoon to its toleram 

 of the facts (1) that the pparent major environm 

 different extent by differat animals, (2) that man} 

 liefly confined to them trascend their limits, and 

 occur over a large part < two or more regions, it 

 [at these areas, when regaled as animal regions, a 

 in real. They are the rages of conspicuous plar 

 sociated in certain parts soie animals and plants wh 

 lial conditions. These aris are not units in thei 



