i8o ANIMAL LIFE PAST AND PRESENT. 



of such teeth in the upper jaw. From the presence of 

 this single pair of lower cutting teeth, the Marsupials 

 of this group are known as Diprotodonts (two front 

 teeth). 



To this group belong the true Kangaroos, of which 

 the largest species is taller than a man ; the smaller 

 Kangaroos popularly known as Wallabies, as well 

 as the still smaller Bat-Kangaroos, being its other 

 members. All these creatures live on the ground, and 

 progress by leaps; but in New Guinea and North 

 Queensland, we meet with the curious Tree-Kangaroos, 

 in which the fore and hind limbs are of nearly equal 

 length, and the habits of the creatures themselves are 

 purely arboreal. The Phalangers (Opossums of the 

 colonists) form another family of this group, most of 

 the members of which are nocturnal and live entirely in 

 trees. The majority of these Phalangers simply climb 

 from bough to bough, or hang suspended by their 

 prehensile tail ; but some species hence termed flying 

 Phalangers have a fold of skin connecting the limbs, 

 and are thus enabled to take long flying leaps from 

 tree to tree, like the flying Squirrels, to which they 

 present an extraordinary external resemblance. These 

 creatures afford, indeed, a remarkable instance how 

 the same place in the rdle of nature may be occupied 

 by totally different groups of animals, which, from the 

 necessary adaptation of their structure to the same 

 mode of life, attain a more or less close similarity of 

 form. 



Allied to the Phalangers is the curious Koala, a 



