(5) The Order Rodentia is represented by six fam- 

 ilies: 



^1 Tail present 

 ^'l Two upper incisors present 

 '^1 Tail cylindrical or compressed laterally (except 

 flying squirrel) 

 •^1 No quills in the fur 



M Not more than three well developed grinders 

 in each jaw 

 M Hind legs not elongated : rats and mice 



1. MURIDAE 

 ^2 Hind legs elongated for jumping: Jump- 

 ing mice 2. Zapodidae 

 ^2 At least 4 well developed grinders in each 

 jaw 

 ^1 Tail long or moderate: Squirrels and 

 Woodchucks 3. SciURlDAE 

 ^2 Long quills present in fur: Porcupines 



4. Erethizontidae 

 '2 Tail large and flattened: Beavers 5. Castoridae 

 ^2 Four upper incisors present: Rabbits and Hares 



6. Leporidae 



(6) The Order Ungulata is represented by a single 

 family, The Deer 1. CervidaE 



A Classified List of Pennsylvania Mammals 

 There are about fifty-nine species and subspecies 

 of Mammals to be found within the confines of the 

 State. The nomenclature and sequence is based upon 

 that used in Miller's "List of North American Recent 

 Mammals." The list with complete classification is as 

 follows : 



-^ 57 ]H*- 



