104 SKETCH OF THE HISTORY OF MAMMALIA. 



65.— Skull of Tiicutuco. 



was a common occurrence. They are nocturnal in their 

 habits ; and their principal food is afforded by the roots 

 of plants, which is the object of their extensive and su- 

 perficial burrows. Azara says they are so difficult to be 

 obtained, that he never saw more than one. lie states 

 that they lay up magazines of food within their burrows. 

 This animal is universally known by a very peculiar noise 

 which it makes when beneath the ground. A person, 

 the first time he hears it, is much surprised ; for it is 

 not easy to tell whence it comes, nor is it possible to 

 guess what kind of creature utters it. The noise consists 



