VII CHARACTERS OF PHALANGERS 139 
common integument as in the Macropodidae. The hallux is oppos- 
able and nailless. The tail is nearly always long and prehensile. 
The pouch is well developed; the stomach not sacculated; a 
caecum. is present (except 
im arsipes). hese’ are 
really the principal  dis- 
tinctions between the two 
familes. In addition, it 
may be mentioned that the 
lower incisors have not a 
scissor-hke action as in the 
Kangaroos. 
The Phalangers may be 
divided into four — sub- 
families. 
The first of these, that 
of the PHALANGERINAE, 
contains the genera Phal- 
anger (including Cuscus), 
Acrobates, Distaechurus, 
Dromicia,  Gymnobelideus, 
Petaurus, Petaurordes, 
Dactylopsila, Pseudochirus, 
and Trichosurus. 
These genera agree in 
the following generalities :— 
Tail well developed, often 
very long; three incisors 
above, and at least two pre- 
molars both above and 
below; caecum long and 
Fig. 68.—Bones of leg and foot of Phalanger. asi, 
simple ; stomach without Astragalus ; calc, caleaneum ; cub, cuboid ; 
x x ect.cun, ecto-cuneiform ; ént.cun, ento-cunei- 
a cardiac gland ; liver not form ; fb, fibula; mes.cun, meso-cuneiform ; 
very complicated by second- nav, navicular ; tb, tibia ; 7-V, first to fifth 
ss : Car toes. (After Owen.) 
ary, furrows, with a distinct 
caudate lobe; the vaginal median culs-de-sac often coalesced ; 
lungs with an azygos lobe. 
The second sub-family, PHASCOLARCTINAE (with the Koala only), 
is thus characterised :—Tail rudimentary ; cheek-pouches present ; 
superior incisors three, but only one premolar above and below; 
