66 MARSUPIALIA. 
but, in the gentle curve by which the lower margin of the 
jaw is continued along the line of the symphysis to the 
anterior extremity of the jaw, the Phascolotherium re- 
sembles Didelphys more than Dasywrus or Thylacinus. 
It is interesting to find that this analogy is associated 
with a correspondence in the condition of the teeth at the 
anterior part of the jaw. In examining the fossil we can 
scarcely refuse our assent to Mr. Broderip’s opinion, that 
there were originally four incisors in each ramus of the jaw 
of Phascolotherium, as in Didelphys. Of the three incisors 
which are actually present in the fossil, only the internal 
and posterior surfaces are displayed, and not the whole 
breadth of the tooth; so that in the enlarged figure of the 
jaw detached from its matrix, the incisors appear both nar- 
rower and further apart than they really are. The incisors 
in the Thylacinus are of a prismatic form ; and the surface, 
corresponding to that which is exposed on the fossil, forms 
one of the angles, from which the tooth increases in breadth 
to its anterior part, which forms one of the three facets. 
Allowing for this circumstance, which must be borne in 
mind in an endeavour to arrive at the true affinities of the 
Phascolothere, the incisors in that fossil are evidently 
separated by wider intervals than in Thylacinus, Dasyurus, 
or Didelphys ; and the Phascolothere resembles, in this 
respect, as in the smaller proportions of its canine, the 
genus Myrmecobius. 
In the proportions of the grinders to each other, espe- 
cially the small size of the hindmost molar, the Phascolo- 
there resembles the Myrmecobius more than it does the 
Opossum, the Dasyure, or the Thylacine ; but in the form 
of the crown it resembles the Thylacine more closely than 
any other genus of Marsupials. In the number of molar 
teeth the Phascolothere differs both from the Amphithere 
