EDENTATH MAMMALS. 57? 
themselves. Their food is roots, poultry, or wild fruits. 
They have no hair on their tails, but a sort of a scale or 
hard crust, as the beavers have. If a cat has nine lives, 
this creature surely has nineteen ; for if you break every 
bone in their skin and mash their skull, leaving them for 
dead, you may come an hour after and they will be gone 
quite away, or perhaps you may meet them creeping away.” 
(“‘ Perfect Description of Virginia,” 1649.) 
There are squirrel-like flying marsupials (Petawrus), 
marsupial rats, marsupial bears, and marsupial ant-eaters 
(Myrmecobius), but the most characteristic Australian ani- 
mals are the different kinds of kangaroo (Macropus thetidis, 
Fig. 498). 
The largest species, M. giganteus Shaw, is 1-8 metres, or 
nearly six feet long. Kangaroos go in herds, and move by 
a succession of long leaps. 
All marsupials are stupid, low in intelligence, and, in the 
insectivorous and carnivorous forms, of vicious temper. 
With the exception of the opossums, all are confined to Aus- 
tralia, New Zealand, and New Guinea. 
Sub-class 3. Monodelphia.—While in the marsupials the 
termination of the oviduct is double, in the present group 
it is always single, whence the name Monodelphia. The 
members of the group are also called placental Mammalia, 
because the young at birth are of considerable size and 
nearly perfect in development, being nourished until born 
by a highly vascular mass or thick membrane ( placenta) 
supplied with arteries and veins, developed originally from 
the allantois, which is a temporary embryonic membrane. 
The brain, as a rule, presents an advance over that of any 
of the preceding mammals, the corpus vallosum being better 
developed, while the anterior commissures are all reduced. 
There are no marsupial bones, though in some Carnivora 
certain small cartilages appear to represent them. 
There are twelve orders, as follows : 
Order 1. Bruta or Edentata.—These creatures, repre- 
sented by the sloths, ant-caters, pangolins, and armadillos, 
stand next above the non-placentals or marsupials, as the 
brain is but little better developed, the hemispheres in some 
