THE POUCHED ANIMALS. 243 



number of teeth than all the other known mammals, for 

 each half of the lower jaw of the Thylacotherium contained 

 sixteen teeth (three incisors, one canine tooth, six pseudo, 

 and six genuine molars). If the upper jaw, which is 

 unknown, had as many teeth, then the Thylacotherium had 

 no less than sixty-four teeth, just double the number 

 possessed by man. The Primseval Marsupials correspond, 

 on the whole, with the Insectivora among Placental animals, 

 ■ which order includes hedgehogs, moles, and shrew-mice. A 

 second order, which has probably developed out of a 

 branch of the last, consists of the Snouted, or Toothless 

 Marsupials (Edentula), which resemble the Toothless animals, 

 or Edentata, among the Placental animals by their tube- 

 shaped snout, their degenerated jaws, and their correspond- 

 ing mode of life. On the other hand, the mode of life and 

 formation of the jaws of Rapacious marsupials (Creophaga) 

 correspond with those of the genuine Beasts of Prey, or 

 Camivora, among Placental animals. This order includes the 

 pouched marten (Dasyurus) and the pouched wolf (Thyla- 

 cinus) in Australia. Although the latter attains to the size 

 of a wolf, it is but a dwarf in comparison with the extinct 

 Australian pouched lions (Thylacoleo) which were at least as 

 large as a lion, and possessed huge canine teeth more than 

 two inches in length. Finally, the eighth and last order is 

 formed by the marsupials with hands, or the Ape-footed 

 Pouched animals (Pedimana), which live both in Australia and 

 America. They are frequently kept in zoological gardens, 

 especially the different species of the genus Didelphys, and 

 are known by the name of pouched rats, bush rats, or 

 opossums. The thumb on their hinder feet is opposable to 

 the four other toes, as in a hand, and by this they are 



