LADDER 421 



Family of Rats axd Mice 

 Muridae 



(Nearly Two Hundred North American Species) 



Clumsy, thickly furred body; small ears; short tail; small 

 feet with furry soles. 



White Lemming Dicrostonyx torquatus. 



Length of body, 5 inches; tail, 1 incli. 



Heavy animal, head set close to shoulders. Fore limbs 

 with four toes and a small thumb ; long claws for scratching 

 and digging ; five webbed toes on hind feet ; compact scaly 

 tail; soft under-fur with stiff hairs overlying it. Animal 

 secretes a musky odor, from which it takes its name. 



Muskrat Fiber zibethicus. 



Length of body, Hi inches; tail, 11 inches. 



Hats and mice — vermin. Large ears ; bright eyes ; long, 

 naked tails ; no cheek pouches ; fur soft. Mostly vegetable 

 feeders, but some eat insects and occasionally other animal 

 food. 



Field Mouse Microtus pennsylvanicus. 



Length of body, A\ inches ; tail, \\ inches. 



Deer or White-footed Mouse . . . Peromyscus leucopus. 



Length of body, ?j\ inches; tail, '.\\ inches. 



Cotton Rat Sigmodon hispidus. 



Length of body, (J inches ; tail, 4 inches. 



Wood or Pack Rat Neotoma floridana. 



Length of body, 8 inches ; tail, 5] inches. 



Marsh Rat Oryzomys pa/ustris. 



Length of body, (5 inches; tail, 3^ inches. 



Gopher Family 

 G^omyidas 



(Niimlicr of North Aiuenoan Species, Twenty to Thirty) 



Burrowing animals, having large cheek i)Ockets that open 

 outside ; wide cutting teeth; snuill eyes and ears ; short legs. 



