150 MARS UPIALIA 
stout and strong, with large vacuities in the hinder half of the 
palate, and the auditory bulle thick and inflated. Dentition usually 
7 3,¢4, 94, m4. First upper incisor with nearly circular section, 
or only slightly flat- 
tened in front; can- 
ine more or less 
closely approximated 
to third incisor 
(which is very small), 
and situated partly 
in front of the suture 
between the pre- 
maxilla and maxilla. 
Fourth premolar 
large, secant, and 
placed obliquely to 
line of molars. 
7 Molars four-cusped, 
Fie 47.—Left lateral view of skull of Gray Cuscus (Phal- with the inner cusps 
anger orientalis). After Peters. 
of the upper ones 
crescentoid, and imperfect transverse ridges connecting each pair 
of cusps. 
The Cuseuses are curious sleepy-looking animals, inhabiting the 
various islands of the East Indian Archipelago as far west as Celebes, 
and being the only Marsupials found west of New Guinea. As 
already noted, it was a member of this genus, the Gray Cuscus 
(P. orientalis), a native of Amboyna, Timor, and the neighbouring 
islands, which was the first Australasian Marsupial known to European 
naturalists. There are altogether five species known, all of about 
the size of a large cat; their habits resemble those of other Phalan- 
gers, except that they are said to be somewhat more carnivorous. 
Trichoswrus..The members of the genus Jrichosurus are of 
relatively large size, and are distinguished from Phalanger by the 
following characters. Ears more or less hairy behind. Relative 
lengths of toes of fore feet in the order 4, 3, 2, 5, 1. Hair on the 
soles of the hind feet beneath the heel, but not elsewhere. Tail 
thick, not tapering, covered with bushy hair up to the extreme tip, 
which is naked, but with a naked strip on the inferior surface in 
the distal third or half. A gland on the chest. Dentition usually 
a 3,¢4,p2,m 4. Upper incisors of nearly uniform length, the 
first much flattened in front. Canine situated some distance behind 
the third upper incisor, which it scarcely exceeds in size. Last 
premolar and molars very similar to those of Phalunger. 
The true Phalangers comprise two species, of which the best 
known is the Vulpine Phalanger (7. vulpecula), so common in 
1 Lesson, Dict. Class, v’ Hist. Nut. vol. xiii, p. 833 (1828). 
