. GEOGRAPHIC DISTRIBUTION OF LIFE IN NORTH AMERICA, 383 
B. Common to Arctic and Hudsonian. 
NVGIV CENT eNeteeem esos. wick co Skcccn ses cn eons one Gulo luscus. 
City TO lige s/o cise Sos hoc ook cee Canis griseus. 
iinet Gebede Sateco doe CORE sCe Se eee Putorius erminea. 
The Boreal Coniferous Forest division may be subdivided into at 
least two trans-continental zones: (a) Hudsonian and (b) Canadian; 
and a third or “Timber-line zone” may be differentiated from the Hud- 
sonian proper. In speaking of the divisions of the Boreal region on 
high mountains it is customary to add the word alpine to the name of 
the division; thus, Arctic-alpine, Hudsonian-alpine, and so on. 
MAMMALS OF THE BOREAL ZONE, 
(The letter a indicates that the species is known only from mountains, or is in an alpine form.) 
Cervus canadensis. 
Rangifer caribou. 
Alce americanus. 
Mazama montana. 
Ovis canadensis. 
dalli. 
Sciuropterus volans sabrinus. 
Sciurus fremonti. 
movollonensis (a). 
hudsonicus. 
californicus («). 
vancouverensis. 
richardsoni. 
douglassi. 
Tamias cinereicollis (a). 
obseurus (@). 
senex (a) 
speciosus (a). 
townsendi, 
wmbrinus (a). 
quadrivittatus (a). 
amcenus (@). 
luteiventris (a). 
borealis. 
neglectus. 
Spermophilus lateralis. 
castanurus (a). 
chrysodeirus (a). 
cinerascens. 
armatus (a). 
beldingi (a). 
empetra. 
kodiacensis, 
columbianus, 
Arctomys caligatus (a). 
dacota (a). 
flaviventer (a). 
Aplodontia major (a). 
rufa. 
Sitomys americanus areticus. 
austerus. 
Neotoma cinerea drummondi. 
Phenacomys borealis. 
celatus. 
intermedius. 
latimanus. 
longicaudus. 
orophilus (a). 
mungava. 
Evotomys californicus. 
occidentalis. 
Evotomys idahoensis. 
carolinensis (@). 
dawsoni. 
galei (a). 
gapperi. 
brevicaudus. 
Arvicola alticolus (a). 
druminondi, 
nanus (@). 
oregonus, 
mordax. 
longicaudus. 
townsendi. 
macropus. 
xanthognathus. 
Myodes obensis. 
Cuniculus torquatus. 
Zapus hudsonius. 
Erethizon dorsatus. 
epixanthus. 
Lagomys princeps (a). 
schisticeps (a). 
