List of Illustrations 



FACING PAGE 



Beaver Lodges and a Dam . .... 149 



A Pair of Woodchucks by their Burrow (Arctomys monax) . 1 52 



Woodchuck (Arctomys monax) 153 



Prairie Dogs (Cynomys ludovicianus) . . . . % 156 

 Western Spermophile (Spermophilus), photographed in 



Colorado , . . . ... . . . . 157 



Say's Spermophile (Spermophilus lateralis) . . . . 164 



White-tailed Spermophile (Spermophilus leucurus} . . . 165 



Young of Columbia Spermophile (Spermophilus columbianus) . 1 56 



Say's Spermophile in Snow (Spermophilus lateralis). . . 168 

 Young Prairie Dog (Cynomys ludovi cianus) . about one-third 



grown . . ... . , . . . 168 



Western Chipmunk (Tamias quadrivitatus) . . . . 169 



Chipmunk (Tamias striatus) . . . . . . . 172 



Gray Squirrel (Sciurus carolinensis) . . , . . 173 



Red Squirrels (Sciurus hudsonicus gymnicus) . . . . 180 



Young Red Squirrel (Sciurus hudsonicus gymnicus) . . . 181 



Hoary Marmot (Arctomys Pruinosus} . . . . . 181 



Pine Squirrel (Sciurus hudsonicus richardsoni) . . . 184 



Flying Squirrel (Sciuropterus volans} . ... . 185 



Common Mole (Scalops aquaticus) . . . . . 200 



Star-nosed Mole (Condylura cristata) ..... 200 



Marsh Shrew (Sorex palustris) ...... 200 



Four Common Eastern Bats . 201 



Sea-lion (Zalophus californianus} 204 



Sea-lion (Zalophus calif ornianus) , barking .... 205 



Walrus Bulls and Cows (Odobenus rosmarus) .... 208 



Fur Seals (Otoes alascanus) . . . . . 212 



Harbor Seals (Phoca Vitulind) . .. . .. . ..212 



Otter (Lutra canadensis) . ... . ... 213 



Skunk (Mephitis putidd), crossing a stream . . . . 232 



Mink (Putorius vison) . v . ... . . .. . 233 



Weasel (Putorius noveboracensis) . . ; . . . 233 



American Sable or Pine Marten (Mustela americand) . . 240 



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