LADDER 419 



Musk Ox (really a big sheep) .... Ovibos moschafus. 



lie'iglit at shoulder, 4^ feet. 



Males and females witli horns nearly equal in size. 



American Bison, or Buffalo ..... Bison bison. 



Height at shoulder, 5|-G feet. 



THE ORDER OF GNAWERS 

 Rodentia 



The largest and most widely distributed group of Mam- 

 mals, found in all parts of the world. More than nine 

 hundred have been named, and new ones are constantly 

 being found. 



These gnawers are mostly small animals, with four strong 

 cutting teeth, living on or under the surface of the ground 

 or in trees, a few l)eing expert swimmers. They are chiefly 

 vegetable eaters, though a few prefer animal food. 



Family of Squirrels 

 Sciuridae 



(More than Sixty North American Species) 



Sciurus and Sciuropterus — Tree Squirrels 



Meaning those who " sit in the shadow of the tail." Good- 

 sized ears, climbing feet, the front having four and the back 

 five sharp long claws. Sometimes having pouched cheeks 

 for carrying food, and, usually, long, plumy tails. 



Flying Squirrel ...... Sciuropterus volans. 



Length of body, Oi inches ; tail, 5 inches. 

 Red Squirrel Sciurus hudsonicus. 



Length of body, 7^ inches ; tail, (Ji inclies. 

 Gray Squirrel Sciurus carolinensis leucofis. 



Length of body, K)J inches ; tail, 10^ indies. 

 Fox Squirrel Sciurus niger cinereus. 



Length of body, lo inclies; tail, \o\ inches. 



