hystricida: 



485 



(E. Jnrsufi/s), a stout heavily -1 milt animal, with long hairs almost 

 or quite hiding the spines; four anterior and five posterior toes ; 

 and a short stumpy tail. It is a native of the greater part of 

 Canada and the United States where there is any remnant of the 

 original forest left. Remains of Erefhizon occur in cavern-deposits 

 in Pennsylvania. 



Syneth&res} — This genus contains some eight or ten species, 

 known as Tree Porcupines (Fig. 214), found throughout the tropical 



Fig. 214. — The Tree Purcupine (Synetheres prehensilis). 



parts of South America, and one of them extending northwards into 

 Mexico. They are of a lighter build than the Ground Porcupines, 

 are covered with short, close, many-coloured spines, often mixed with 

 hairs, and their tails are always prehensile. Their hind feet have 

 only four toes, owing to the suppression of the hallux ; but they 

 have a peculiar fleshy pad on the inner side of the foot, between 

 which and the toes boughs and other objects can be firmly grasped 

 as with a hand. Vertebras : C 7, D 17, L 5, S 3, C 36. An extinct 

 species of this genus has been described from the cavern-deposits of 

 Brazil. 



1 F. Cuvier, Mem. du Mus6vm, vol. ix. \<. 413 (1822). "Sinethere." 



