VERTEBRATA. 



of kinds forms a complete covering. The hairs arise 

 each from a root placed in a pit or follicle situated 

 over an eminence or papilla o£ the skin. 



Classification of Mammalia. — The Marsupialia 

 are, after the Monoteemes, the least highly developed 



Fig. 106.— Didelj)hj/8 domsera, an Opossum from Surinam, carrying its 

 young on its back. 



of the Mammalia. They are the archaic type of mam- 

 mals, and now survive chiefly in the Australian, region. 

 Their especial peculiarity is, that they have a pouch or 

 marsupmm, in which they carry their young about, to 

 keep them warm and shelter them from danger. Some 



