MARSUPIALS. 247 



{Myrmecobius), but the most characteristic Australian ani- 

 mals are the different kinds of kangaroo {Macropus theti- 

 dis, Fig. 286). 



The largest species, M. giganteus, is 1.8 metres, or nearly 

 six feet long, being as large as a sheep and sometimes weigh- 

 ing 140 i^ounds. Like other kangaroos, it goes in herds, 

 and moves by a succession of long leaps, clearing obstacles 

 seven or eight feet high. 



All marsupials are stupid, low in intelligence, and, in 

 those which eat flesli, of vicious temper. With the excep- 

 tion of the opossums, all are confined to Australia, New 

 Zealand, and New Guinea. 



Sub-Class III. Monodelphia. 



General Characters of Placental Mammals. — The mem- 

 bers of this group are called jjlacental Mammalia, because 

 the young at birth are of considerable size and nearly per- 

 fect in development, being nourished until born by a highly 

 vascular mass or tliick membrane {placenta) supplied with 

 arteries and veins, developed originally from the allanfois, 

 which is a temporary embryonic membrane. The brain, 

 as a rule, is higher than that of any of the preceding mam- 

 mals. 



Orders of Placental Mammals. 



1. No incisor teeth; sometimes entire- 



ly toothless Bruta: Sloth, etc. 



2. Rodents; with large incisor teeth. . Glires: Rat, etc. 



3. Fore limbs often adapted for bur- 



rowing; teeth sharp; feeding on 



insects Inseciimra: Moles,, etc. 



4. Fore limbs long, webbed, and 



adapted for flying Claroptcra: Bats. 



with all its limbs supple, as if just dead; nor v.-ould any kicks, cuffs, 

 or handlings avail to produce the least token of life, not the opening 

 of an eyelid, or the moving of a foot." The only sign of life is the 

 tip of the prehensile tail, the end of which remains coiled up; in 

 death this would be relaxed permanently. 



