258 MARSUPIALIA. — 
order of their affinities, the few and diversified © The incisors are of equal and re 
forms of this implacental group which are at larly arranged in the segment of a circle wi 
present known. 
In the subjoined classification the modifica- 
tions of the digestive system have been taken as 
the guide to the formation of the primary groups 
of the Marsupialia. 
The Continent, however, in which the Mar- 
Supials exist in greatest number and variety, 
is characterized by the paucity of organized 
matter upon its surface, and consequently few 
of the species are nourished by a well-defined 
diet. Re dncpe carnivorous quadruped could 
without much difficulty have found subsistence 
in the wilds of Australia, prior to the intro- 
duction of civilised man and his attendant 
herds; and we find, in fact, that the native 
genera which are the most decidedly carnivo- 
rous do not include species larger than the dog. 
We can only reckon among these strictly car- 
nivorous species the Thylacines and the Da- 
syures ; and, on the other hand, not more than 
two or three Marsupial genera feed exclusively 
on vegetable substances. The remainder de- 
rive a promiscuous nutriment from dead or 
decaying animal and vegetable matter, crus- 
tacea, and the refuse of the sea-shore, insects 
in their perfect and larva states, live birds, 
young and succulent sprouts, leaves, fruits, 
The terms, therefore, which will be given 
to the different primary subdivisions in the 
present classification of the Marsupialia must 
not be understood to indicate strictly or ex- 
clusively the nature of the food of the species 
severally included in these groups, but rather 
their general tendency to select for their support 
the substances implied by those designations. 
Classification of the Marsupialia.* 
Tribe I. SARCOP HAGA. 
The genera in this tribe are characterized by 
an important anatomical condition, viz. the ab- 
sence of an intestinum cecum. 
Genus 1. THYLACINUS. ( Fig. 80.) 
Fig. 80. 
Thylacinus Harrisii, one-third natural size. 
ie 48 : a 
Incisors 3—9 canines 7—;° 
3—3 / 4—4 
3-3; molars asa 
™ Proceedings of the Zoological Society, Jan. 8, 
premolars 
* = 46. 
an interspace in the middle of the 
both jaws. The external incisor on e 
is the strongest. The laniary or canine t 
are long, strong, curved, and pointed, hi 
those of the dog tribe. The spurious mol 
in this as in all other Marsupials have t 
roots; their crown presents a simple co 
pressed conical form, with a posterior tuber 
which is most developed on the hindn 
The true molars in the upper jaw are unequé 
triangular, the last being much smaller than 
rest; the exterior part of the crown is rai 
into one large pointed middle cusp and 1 
lateral smaller cusps obscurely developec 
small strong obtuse cusp ga om 
inner side of the crown. molars of | 
lower jaw are compressed, tricuspidate, 
middle cusp being the longest, especially 
the two last molars, which resemble closely t 
sectorial teeth (dents carnassiérs) of the 
and cat. 
The fore feet are 5-digitate, the hind 
4-digitate. On the fore foot the middle 
is the longest, the internal one or pollex| 
shortest; but the difference is slight. On 
hind foot the two middle toes are of n 
equal length and longer than the two lat 
toes, which are equal. All the toes are arn 
with strong, blunt, and almost straight claw: 
The only known species of this genus,= 
Thylacine ( Thylacinus Harrisii, Temm.,, - 
delphys Cynocephalus, Harris,) is a native 
Van Dieman’s Land, and is called by 1 
Colonists the “ Hyena.” It is es largest 
the carnivorous Marsupials, equalling in | 
the shepherd's dog, ay is of a tron bui 
and stands lower on its legs. Its head is 
disproportionate magnitude. The prinej 
characteristic of its colour is the trans 
black bands which traverse the back. It dwi 
in caverns and holes in the rocks, and seeks 
prey by night, devouring the smaller n 
quadrupeds, and at the present 
committing destructive ravag 
the numerous flocks of sheep ¥ 
have been introduced by the E 
pean settlers into the island, 
the spines of the Echidna seen 
be no defence against the des 
tive and voracious propensitie 
the powerful Thylacine, for the} 
digested remains of one of t 
monotremes have been found ij 
stomach. ve 
In confinement the Thylat 
utters from time to time a 
guttural cry, and appears in the 
time exceedingly inactive and 
pid, presenting an almost cont 
movement of the nictitating n 
brane of the eye. = 
J 
n 
af 
1839. The series of skulls carefully preparec 
Mr. Waterhouse at the Zoologi Society © 
afforded me the chief materials for the illustra 
of the dental formule of the different Mars 
genera. : 
