i 
THE PHALANGERS, &C¢. 44 
As regards their distribution in space, the Phalangeride 
range not only over Australia and Tasmania, but are likewise 
found in New Guinea and the Austro-Malayan islands, their 
extreme westerly limit being Celebes. The two most peculiar 
and aberrant genera (Phascolarctus and Tarsipes) are, however, 
exclusively Australian. 
As is well remarked by the author of the admirable technical 
work the “ British Museum Catalogue of Marsupials,” the Pha- 
langers and their allies may be regarded as the most generalised, 
and therefore presumably the most ancient types of Diprotodont 
Marsupials at present existing. Related closely to one another 
in respect of external form and appearance, they differ very 
widely in regard to their dental characters, thus showing that 
specialisation has played a large part in the latter. It is scarcely 
necessary to observe that the numerous small functionless teeth 
occurring in so many members of the family are remnants of 
the fuller series of teeth characterising the second and more 
' generalised primary sub-division of the Marsupials known as the 
Polyprotodonts. And it may be incidentally mentioned here, 
_ as tending to show the origin of the comparatively specialised 
_ Diprotodonts from the generalised Polyprotodonts that even in 
such a highly specialised group as the Kangaroos vestiges of at 
_ least five pairs of incisor teeth have recently been discovered 
in the foetus. 
In their modes of life the Phalangers and their allies are 
essentially arboreal creatures, the great majority of them being 
largely assisted in their climbing by their highly prehensile tail. 
Some, however, have “gone one better” than this, and have 
developed large parachute-like expansions of skin from the 
sides of the body, by means of which they are able to take long 
_ flying leaps from bough to bough, and thus from tree to tree. 
And it may be mentioned here as a somewhat remarkable 
circumstance that the different groups of these Flying Phalan- 
