OF THE CLASS MAMMALIA. 



281 



at which it works in society, in the most solitary parts of 

 North America ( 331, p. 174). 



The neighbourhood of man seems to prevent the beaver 

 from working in society, as we find that the beavers of the 

 Rhine are solitary, and never construct habitations like those 

 of Canada, although they seem to belong to the same species. 

 The beaver was formerly indigenous to many European 

 countries, and even to Britain. 



419. The order of edentata (toothless animals) seems 

 to fill up the link between the unguiculata and the ungulata, 

 for the nails acquire a great development, and cover a large 



Fig. 246. Head of the Armadillo. 



portion of the extremity of the fingers and toes ; but that 

 which characterizes them is the absence of teeth in the front 

 of the mouth (Fig. 246). 



The dentition is composed of canine and molar teeth only, 

 and even these are also sometimes absent (Fig. 29) ; the 

 edentata live, in fact, on soft insects, or leaves easy to gather. 

 As examples of this group, we cite the armadillos (Fig. 247), 

 the pangolins (Fig. 196), and the ant-eaters. 



Fig. 247. The Armadillo Cabassou ; the Tatou, or Tatouay of D'Azzara. 



420. The order of pachydermata belongs to the division 

 of mammals having hoofs, and is composed of all the ungu- 

 lata in which the stomach is formed in the usual way, and 



