198 MAMMALIA ORDER XI.MARSUriALIA. 



kangaroo tribe on the one hand, and the phalangers on the other. Indeed, 

 it is chiefly owing to the presence of a pocket like pit on the outer side of 

 the hinder part of the bone of the lower jaw that it is referred to the 

 present rather than to the following family. It is regarded as representing 

 a distinct sub-family (Hypsiprymnodontince) of the Macropodidce, characterised 

 by the small, weak, and nearly equal-sized claws, the presence of five toes in 

 the hind foot (the first of which can be opposed to the rest), the naked and 

 scaly tail, and the oblique position of the short last pre-molar tooth. In size 

 this creature is very small, with a rat- like bodily form, a completely bare nose, 

 large, thin, and naked ears, the hind and fore limbs of nearly equal length, 

 and adapted for walking, the first toe of the hind-foot elongated and without 

 a claw, the fourth toe of the same not abnormally large, and the tail cylin- 

 drical and tapering, with some hair at the root. The musk-kangaroo is a 

 partially arboreal animal, which is mainly diurnal, and frequents scrubs on 

 the banks of rivers and in the coast-range. Either one or two young are 

 produced at a birth ; and the characteristic musky odour is more pronounced 

 in the female than in her partner. 



Owing to the intermediate characters presented by the musk-kangaroo, 

 the differentiation of the phalanger tribe (Phalangeridce) from the Macropodidce 



is by no means so easy as would be the case were that 



Phalanger creature non-existent. There are, however, two leading 



Tribe. features which may be regarded as absolutely distinctive of 



the former group. In the first place, each branch of the 

 lower jaw-bone lacks the deep pocket-like pit on the outer side of its hinder 

 extremity so characteristic of the kangaroo tribe ; and, secondly, the 

 aperture of the pouch of the female is directed backwards instead of forwards. 

 Among other more or less distinctive features, the following may be 

 enumerated : Five toes are present in both the hind and fore feet, those of 

 the latter being usually of nearly equal size ; while in those of the former the 

 second and third are syndactylous, the fourth is the largest, the fifth but 

 little smaller, and the first large, opposable to the rest, and terminating in a 

 broad, clawless pad. With the exception of the koala, the tail is long and 

 generally prehensile ; and the stomach is simple. The dentition is extremely 

 variable, owing to the frequent presence of a number of small functionless 

 teeth in the front portion of the jaws. It may be said, however, that, as a 

 general rule, there are three pairs of upper, and one of functional lower 

 incisors, and that the latter never have the scissor-like action characteristic 

 of the kangaroos. The last of the two or three pre-molars usually present is 

 generally furnished with a rather sharp-cutting edge, and is placed obliquely 

 to the line of t.he molars, with its front edge everted ; and the molars, of 

 which there are usually four pairs, have either blunt tubercles, or sharp- 

 cutting crests. The family includes not only the animals properly known as 

 cuscuses and phalangers (the mis-called opossums of the Australian colonists), 

 but likewise the flying-phalangers, the koala or native bear, and the long- 

 snouted pouched mouse. The geographical range of this extensive family 

 includes not only Australia, Tasmania, and Papua, but likewise Celebes, and 

 some of the other Austro-Malayan islands. The koala and long-snouted 

 pouched mouse are, however, exclusively Australian. All are essentially 

 arboreal and nocturnal in their mode of life, most using their prehensile tails 

 to assist in climbing, while a few are enabled to take (like the flying squirrels) 

 long flying leaps by the aid of parachute-like expansions of skin from the 

 sides of the body. The great majority of the phalanger tribe are vegetable 



