THE PHALANGER TRIBE 1425 



All the above-mentioned types may be included in the Kangaroo family, but 

 there were other forms which cannot be included in any existing group. Largest 

 of these is the gigantic diprotodon, with a skull of about a yard in length, huge 

 chisel-like first upper incisor teeth, and no perforation in the side of the lower jaw. 

 This creature, which must have been fully as large as the largest rhinoceros, evi- 

 dently walked on all four limbs in the ordinary manner. Another allied but some- 

 what smaller animal was the notothere, characterized by its extremely-short skull; 

 it appears to have been to some extent intermediate between the kangaroos and the 

 wombats. 



THE PHALANGER TRIBE 



Family PHALANGERID^E 



Under the generax term of phalangers a name referring to the union of the 

 second and third toes of the hind-foot may be included a large number of small or 

 medium-sized Australasian Marsupials of arboreal habits, which are so closely con- 

 nected with the kangaroo tribe through the five-toed kangaroo as to render the dis- 

 tinction between the two families a matter of some difficulty. 



The whole of these animals are characterized by their thick, woolly coats; and, 

 with the single exception of the koala, they have long tails, which are frequently 

 endowed with the power of prehension. The fore and hind-limbs instead of present- 

 ing the disproportionate relative lengths characterizing most of the kangaroos, are 

 of the normal proportions, and the front paws are provided with five nearly equal- 

 sized and clawed toes. The structure of the hind-feet is essentially the same as 

 in the five-toed kangaroo; that is to say, there is a nailless first toe which can be 

 opposed to the others, while the second and third are slender and inclosed in a com- 

 mon skin. Whereas, however, in the five-toed kangaroos the fourth toe is much 

 longer and more powerful than all the others, in the phalangers it is not much 

 larger than the fifth. The whole group differs from the kangaroos in the absence 

 of any pit on the outer sides of the hinder portion of the lower jaw, as shown in the 

 accompanying figure of the skele- 

 ton; while if there be any per- 

 foration in this portion of the 

 jaw, it is extremely minute. As 

 regards the dentition, there are 

 always three pairs of upper in- 

 cisor teeth, of which the first is 

 elongated, and likewise a well- 

 developed tusk or canine; while SKELETON AND JAWS OF PHALANGER. 

 in the .lower jaw the single func- 

 tional pair of incisors are large and pointed, although they lack the scissor-like action 

 characterizing those of the kangaroos. In the adults there are usually five func- 

 tional cheek-teeth, of which the last four are molars, and the other the permanent 

 premolar. The premolar in each jaw has a tall cutting crown, set obliquely to 

 the line of the molars; while the latter, of which the fourth may be absent, have 

 usually blunt tubercles on their crowns, although they may be of a cutting type. 

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