100 
OSTEOLOGICAL GALLERY. 
[Case 24, J 
Wombats, which, with but few exceptions, live chiefly upon vegetable 
food ; to the latter, carnivorous both in structure and habits, the 
Opossums, Dasyures, and Bandicoots. 
The Kangaroos (Case 24, Div. B) belong to the first group ; 
their dental formula, when fully developed, being I. C. Pm. r!, 
M. ^x2 = 34; some of the anterior grinding-teeth, however, are 
generally lost before the posterior are in position. The modifications 
of the bones of the hind feet accompanying their extraordinary 
“ syndactylous structure has been already referred to (p. 54). 
Skeletons ai*e exhibited of a male and female Red Kangaroo 
{Macropus rufus), of a Tree-Kangaroo {Dendrolagus), and a Rat- 
Kangaroo [Potorous). 
Numerous fossil remains of animals allied to Kangaroos, some 
as large as a Rhinoceros, have been found in the fluviatile deposits 
of Australia, among which may be specially mentioned the huge 
Viprotodon australis, whose head is figured in the Geological 
Guide, p. 31. 
The Phalangers [PhalangeridcP) differ from the Kangaroos by 
the possession of a large opposable hallux, and by the comparative 
shortness of their hind feet. Their teeth are remarkably variable 
in form and number, the ten genera of the family being founded 
almost entirely on these variations. The dental formula ranges 
from I. f, C. 1, Pm. f , M. f x 2 = 28, to I. f, C. |, Pm. M. |, 
X 2 = 40. In the aberrant Tarsipes rostratus the molar teeth are 
so reduced and variable that no definite number can be assigned to 
it. The feet are syndactylous, as in the Kangaroos, but the dis- 
proportion between the bones of the united second and third toes 
on the one hand, and the fourth on the other, is not so great as in 
those animals. 
The Phalangers vary in size from animals as small as a mouse, 
as for example Acrohates pygmams, toothers larger than a cat, such 
as the Koala {Phascolarctus cinereus). Skeletons are exhibited of 
the latter animal, of a Cuscus [Phalanger maculatus), and of a 
Flying Phalanger {Petaurus sciureus). 
The Pliascolomyidce, or Wombats, arc the only Marsupials with 
rootless teeth and an equal number of incisors in each jaw, their 
dentition being I. C. j], Pm. M. | x 2 = 24. The incisors 
are large and cutting, with the enamel confined to their anterior 
