C Carpophaga. Intermediate between the Kangaroos and the typical members of the present section (the Phalangers) is the Phascolarctos - the "native sloth" or "bear" of the Australian colonists, and the "koala" of the natives (fig. 365). This curious animal is about two feet in length, having a stout body, covered with a dense bluish-grey fur. The tail is wanting; and the feet are furnished with strong curved claws, which enable the animal to pass the greater part of its existence in trees. In this it is greatly assisted by the fact that all the feet are prehensile, the hallux being opposable, and the digits of the fore-limb divided into two sets, the thumb and index-finger being opposable to the other fingers. The dental formula is The koala is a slow animal which feeds on the foliage of the trees in which it spends its existence.

Fig. 365.   Koala or Kangaroo bear (Phascolarctos cinereus) (After Gould.)

Fig. 365. - Koala or Kangaroo-bear (Phascolarctos cinereus) (After Gould.)

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The typical group of the carpophagous Marsupials is that of the Phalaugistidae or Phalangers, so called because the second and third digits of the hind-feet are joined together almost to their extremities. The family includes a number of small Marsupials, fitted for an arboreal existence, to which end the hallux is opposable and nail-less, whilst the four remaining toes of the hind-feet have long curved claws. The tail, too, is generally very long, and its tip is usually prehensile. The Phalangers are all small nocturnal animals which live upon fruits and other vegetable food. The best known of them is the Australian Opossum or Vulpine Phalanger (Phalangista vulpina), which must not be confounded with the true or American Opossums, which belong to another section of the Marsupialia. The Phalangers, namely, are distinguished from the Opossums properly so called, amongst other characters, by their dentition, the canine teeth being always very small and functionally useless in the lower jaw, and sometimes in the upper jaw as well. The Phalangista vulpina is nocturnal and arboreal in its habits, and its flesh is esteemed a great delicacy by the native Australians, with whom opossum-hunting is a favourite pursuit.

The flying Phalangers or Petauri are closely allied to the true Phalangers, but differ in not having a prehensile tail, and in having a fold of skin extending on each side between the sides of the body and the hind and fore limbs. By the help of these lateral membranes the Petauri can take extensive leaps from tree to tree; but though called "flying" Phalangers, they have no power of flight properly so called. They are beautiful little animals, nocturnal in their habits, and having the body clothed with a soft and delicate fur.

(B.) Polyprotodontia. - Lower incisors more than two in number; canines more or less well-developed; molars cuspidate or with sectorial crowns.