MAMMALIA, 415 
The genus Phalangista has a prehensile tail, and for the sake of conve- 
nience may be divided into four sections. In the first, Cuscus, the basal 
portion of the tail only is covered with hair ; the ears are short, almost hid- 
den by the fur of the head, and the eyes with vertical or nearly vertical 
pupils. The species of this section are of moderate size, and have a dense 
fur more or less woolly in its texture. They are confined to the islands of 
Celebes, Amboyna, Banda, Waigiu, Timor, New Guinea, and New Ireland. 
In Trichosurus the tail is densely clothed with fur, with the exception of a 
part of the under surface commencing at the point, and more or less 
extended towards the root of the tail; ears distinct, usually long; eyes 
with the pupil round. Fore feet normal. The species of this section 
inhabit Australia. The section Pseudochirus includes the species with 
the two inner toes of the fore-foot separated from, and partially opposed to, 
the other three; the tail clothed, excepting at the apex beneath, with short 
adpressed hairs; the ears short and rounded; and with six molar teeth, 
forming a continuous series, on either side of the upper jaw. Inhabits 
Australia. In Dromicia the ears are moderate, nearly naked, and folded ; 
toes with the nails small ;. tail covered with small adpressed hairs, except- 
ing at the base where it is covered with fur like that of the body, naked 
beneath at the extremity. Small species, inhabiting Australia and Van 
Diemen’s Land. 
A fossil species of Phalangista, agreeing in its general features with P. 
vulpina, has been discovered in the caverns of Wellington Valley. 
The genus Petaurus, or flying phalangers, is composed of those Phalan- 
gistide provided with a membrane extending from the fore to the hind 
legs, and filling the interspace of these legs; the tail is well clothed with 
hair throughout, and generally very long. In the section Petaurista the 
ears are broad, rather short, rounded, and densely clothed with long fur on 
the outer surface; the toes of the fore feet nearly equal in length; the 
flank membrane extending only to the elbow joint; with seven well 
developed molar teeth in the upper jaw and six in the lower. The true 
molar, provided with pyramidal cups. The petauri are nocturnal in their 
habits, and hide during the day in the hollows of trees. In Belideus the 
ears are long and nearly naked; the tail bushy; the lateral membrane 
extending to the outer finger; the two outer fingers of the hand are long 
and equal to each other, or very nearly so; the second and third fingers 
distinctly shorter than these ; the second the shortest of the two latter, and 
the inner, or first finger, very short. The Acrobata have a tail moderately 
long, clothed above and beneath with short adpressed hairs, and fringed on 
either side with long hairs; the ears are moderate, well clothed externally 
with fine hairs; the feet provided with small claws, the thumb of the hind 
foot is large, the flank membrane scarcely extending to the wrist. The 
type of this section is the pigmy flying opossum (A. pygme@us). 
The genus Tarsipes includes a very remarkable species (7. rostratus) 
from the western coast of Australia, resembling the phalangista in dentition, 
only with the difference that the teeth are in rather a rudimentary condi- 
tion. The head is elongated, the snout pointed as in some Peramelide. 
619 
