724 RODENTIA. 



GENUS ERETHIZON. 



The three species are distributed as follows : One, throughout Canada 

 and as far south as Northern Pennsylvania and west to the Mississippi ; 

 the second from California to Alaska and west to the Missouri ; the third 

 in the northwest part of South America. 



The Canadian Porcupine, Erethizon dorsatum (Plate LVIII), is also 

 called the Urson. Its chief food consists of living bark, which it strips 

 from the branches as cleanly as if it had been furnished with a sharp 

 knife. When it begins to feed, it ascends the tree, commences at the 

 highest branches, and eats its way regularly downward. 



In the work of Messrs. Audubon and Bachman is a very amusing 

 little story of the manner in which the tame Urson above mentioned 

 repelled an attack made upon it by a fierce dog. 



" A large, ferocious, and exceedingly troublesome mastiff belonging 

 to the neighborhood, had been in the habit of digging a hole under the 

 fence, and entering our garden. Early one morning we saw him making 

 a dash at some object in the corner of the fence, which proved to be our 

 Porcupine, which had, during the night, made its escape from the 

 cage. 



" The dog seemed regardless of all its threats, and probably sup- 

 posing it to be an animal not more formidable than a cat, sprang upon it 

 with open mouth. The Porcupine seemed to swell up in an instant to 

 nearly double its size, and as the dog pounced upon it, it dealt him such 

 a sidewise blow with its tail, as to cause the mastiff to relinquish his hold 

 instantly, and set up a loud howl in an agony of pain. His mouth, 

 tongue, and nose were full of Porcupine quills. He could not close his 

 jaws, but hurried, open-mouthed, off the premises." 



GENUS CERCOLABES. 



The twelve species of this genus range from Mexico to Paraguay on 

 the east side of the Andes. They are distinguished by long tails, usually 

 prehensile, and short quills. 



The Brazilian Porcupine or Coendoo, Cercolabes prehe?isilis (Plate 

 LIX), as might be presumed, from the prehensile tail and the pecu- 

 liarly armed claws, is of arboreal habits, finding its food among the lofty 

 branches of trees. On the level ground it is slow and awkward, but it 



