VII MINUTE ARBOREAL FORMS I4I 
vulpina), like its American pseudo-namesake (a true Opossum, 
genus Didelphys), “plays *possum” on occasions. The dental 
formula is 13 Ci Pm2M¢._ The ears are shortish. 
The Ring-tailed Phalangers, Pseudochirus, are more widely 
distributed than the last two genera; they range from Tasmania 
in the south to New Guinea in the north. They are not, however, 
ring-tailed, though the tip of the tail is generally white. As 
in the last genera, which have prehensile tails, the end of this 
appendage is naked. The mammae are four. The tooth formula 
is I13C3Pm3 M4. There are some ten species of the genus. 
The Striped Phalanger, Dactylopsila trivirgata, is an animal 
about a foot long, whose identity can be ascertained by its striped, 
black and white skin. It is an arboreal creature that lives 
apparently both on leaves and grubs like so many arboreal 
creatures of quite different groups—Squirrels, for instance, and 
New-World Monkeys. The tooth formula is 13 C$ Pm 3 M 4. 
Gymnobelideus leadbeatert 1s a small creature with “a body 
6 inches in length. It is restricted to the colony of Victoria. 
The general look is that of Petawrus; the ears are naked. 
Dromicia is a genus of Phalangers which although devoid of 
a parachute, such as is possessed by certain genera that will be 
considered immediately, is able to leap with great agility from 
branch to branch. The ears are large and thin and almost 
naked ; the tooth formula is 13 C3 Pm3 M4. They are minute 
creatures, the longest measuring, with the tail, but 10 inches. 
Dormouse-Phalanger is a name sometimes given to them. 
There are four species, ranging from Tasmania to New Guinea. 
The name Dormouse as applied to the genus seems to be owing 
to the way in which they hold a nut in the paws when feeding. 
D. nana is 4 inches long, with a tail of nearly the same 
length. It is thick at the base. 
Distaechurus is the last genus of non-flying Phalangers. Its 
name refers to the arrangement of the hairs on the tail, which 
are disposed on either side in a row like the vane of a feather. 
The tooth formula is I 3 C3} Pm M 3, very nearly as in Acro- 
bates. The ears are as in that genus. 
Petaurus is the first genus of the Flying Phalangers, all of 
which are provided with a parachute-like expansion of the skin 
between the fore- and hind-limbs; the ears are large and naked ; 
and the tooth formula is 13 C} Pm3M4#. There are three 
