VERTEBRATA l8l 



the kangaroo covers the olfactory lobes. All have the 

 four kinds of teeth, and all are covered with fur, never 

 with spines or scales. Except the opossums of Amer- 

 ica, all are restricted to Australia and adjacent islands. 

 The marsupials are almost the only mammals of 

 Australia, there being very few species of placental 

 mammals. The marsupials have here developed into 

 forms corresponding in their habits to the orders of 

 placental mammals in the rest of the world. The 

 kangaroos take the place of the large herbivores 

 the ungulates. The thylacinus and dasyurus are the 

 marsupial carnivora. Other forms are squirrel-like in 

 shape and habits, and still others are insectivorous. 



SECTION B. Eutheria 



In these mammals the young are connected with the 

 mother by means of a vascular structure, the placenta, 

 by which they are nourished. They are born in a rela- 

 tively perfect condition. There is no marsupial pouch. 

 The following orders are included : 



i. Edentata. This strange order contains very di- 

 verse forms, as the leaf-eating sloths and the insectivo- 

 rous ant - eaters and 

 armadillos of South 

 America, and the pan- 

 golin and orycteropus 



Of the Old World. The FIG 168. Skull of the great ant-eater (Myrrne- 

 o-io-antiV frccilc rn^cro cophaga jubata} : 15, nasal ; n, frontal; 7, parietal; 

 gig dUlll l US, i ic^d- 3> superoccipital; 2, occipital condyles; 28, tym- 

 therium and P"lvDtodon panic; 73, lachrymal; 32, lower mandible. Teeth 

 . wanting. 



belong to this group. 



The sloths and ant-eaters are covered with coarse hair ; 

 the armadillos and pangolins, with an armor of plates 

 or scales (Fig. 298). The ant-eaters and pangolins 

 are strictly edentate, or toothless ; the rest have molars, 

 wanting, however, enamel and roots. In general, it 



