MAMMALIA. 



317 



FIG. 343. Skull of a gnawing animal 

 (Rodent) , showing the large chisel- 

 teeth in front, and the gap between 

 these and the hind teeth. 



Order VI. Gnawing Animals (Rodcntia). General 

 Characteristics. The animals of this order have no canine 

 teeth, but in each jaw are two powerful, chisel-like incisors 

 (Fig. 343), that are renewed 

 as fast as they wear away. 

 The molar teeth are flat, 

 and seldom exceed four in 

 each jaw. The lower jaw 

 is so articulated with the 

 skull that the motion is 

 forward and back instead 

 of horizontal. The limbs 

 are adapted for walking, 

 climbing, flying, or bur- 

 rowing. 



Hares and Rabbits (Leporida). The hares (Fig. 

 344) and rabbits have a wide geographical range, and are 

 distinguished by long ears, the presence of small teeth be- 

 hind each of 

 the incisors, 

 powerfully de- 

 veloped hind- 

 legs, and short, 

 bushy tails. 

 The fore - feet 

 are five - toed, 

 the hinder ones 

 having four. 

 Many have the 

 feet lined with 

 hair beneath. 

 The white 

 hare (Lepus 

 Americanus} 



and gray rabbit are well-known species. The former 

 ranges from Virginia to Labrador. The water-rabbit of 



FIG. 344. European hare (Lepus timidus). 



