ORDER OE RODENTIA. 
465 
foot and a half, and that of its tail ten inches. It lives on trees, 
and all its movements are excessively slow. It appeared to dislike 
exertion, and Azara noticed one that remained in the same 
posture for forty-eight hours. In short, it is a lazy, indifferent, 
and apathetic animal, which only exerts itself to obtain food. 
Azara possessed five of them, which he fed on leaves, fruits of 
all kinds, manioc, maize, and bread. 
Synetherus Genus . — The only known species is the Mexican 
Fig. 197.— Canadian Porcupine ( Erethizon dorsatum). 
Porcupine, which has its body entirely covered with quills. It is 
found in the forests of Guiana, Brazil, and Mexico. 
Aulacodus Genus . — We mention these animals (Fig. 198) because 
their shape differs essentially from that of other Porcupines. 
Their head and body are much more elongated, and their toes 
shorter. Their tail is rather long, and covered with prickly hair. 
These animals are as large as Rabbits, and inhabit western and 
southern Africa. 
The group of Cavies, which comes after the Porcupines, com- 
prehends a certain number of Rodents, differing in appearance, 
which, however, are indubitably connected by certain charac- 
teristics common to all. Their grinders are devoid of roots ; 
their toes, to the number of four in front and three behind, are 
terminated by rounded claws, somewhat similar to hoofs ; they 
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