With the exception of the aberrant long-snouted phalanger, the members of the family Phalangeridae have the normal number of functional incisors, in addition to which there may be one or two rudimentary pairs in the lower jaw.
- The Long-snouted Phalanger (Tarsipes rostratus).
As the first example of the group may be taken the elegant little long-snouted phalanger (Tarsipes rostratus, fig.
The typical members of the group are the cuscuses (Phalanger), ranging from the Moluccas and Celebes to New Guinea, in which the males are often different in colour from the females.
Arboreal species include the well-known opossums (Phalanger); the extraordinary tree-kangaroo of the Queensland tropics; the flying squirrel, which expands a membrane between the legs and arms, and by its aid makes long sailing jumps from tree to tree; and the native bear (Phascolarctos), an animal with no affinities to the bear, and having a long soft fur and no tail.
The common Australian "opossum" or phalanger (Trichosurus vulpecula) has been naturalized in New Zealand, although very destructive to fruit trees; the value of its fur being probably the motive.
The marsupials also attain their maximum development in Australia (" Notogaea " of the distributionists), extending, however, as far west as Celebes and the Moluccas, although in these islands they form an insignificant minority among an extensive placental fauna, being represented only by the cuscuses (Phalanger), a group unknown in either Papua or Australia.