BY C. W. DE VIS, M.A. 13 
in the other New Guinea species between the ears, and 
these differences are accompanied by others which are on 
the whole sufficiently distinctive. 
We have as yet very scanty information about the habits 
and range of these curious marsupials. It is to be hoped 
that both will be ascertained before the extermination of 
animals so defenceless and unadaptive is brought about, 
as it will be at no distant day, by the destruction of our 
coast scrubs; for it seems probable that from the knowledge 
to be acquired respecting them, not a little may be inferred 
respecting the conditions of marsupial life in the old 
diprotodont days of rain and exuberant vegetation. 
Were I warranted in proposing a name for this supposed 
species, I would at once yield to a desire to dignify it by 
association with that of one of our oldest and most respected 
Australian naturalists, Dr. G. Bennett, who has so often 
insisted on the probability of Dendrolagus being indigenous 
to Queensland. Should it prove that the skin before us 
really represents a distinct species, I trust that the name 
D. Bennettianus will be the one conferred upon it. 
To those who take an interest in the great question of 
evolution, the case before us, that of the tree-kangaroo 
(so-called), is one worth consideration. We have here a 
non-saltatory modification, both in habit and structure, of 
the saltatory family of the marsupials. From the evolution 
point of view we may ask whence was it derived? From 
the non-evolution standpoint more directly, what are its 
nearest relatives? Were we to suffer ourselves to be 
guided by general similarity and a certain resemblance in 
seating and balancing faculties, we should trace the tree- 
kangaroo to the rock wallaby, since, superficially considered, 
the passage from the one into the other may appear 
of easy accomplishment by insensible degrees. But 
it happens that it is almost certain that Dendrolagus 
is not a modified Petrogale, but stands in the relation 
of either ancestor or descendant of the kangaroo-rats, 
the proof being that it has the peculiar dentition of 
that section of the Macropide, namely, the enormous 
trenchant premolar and the rudimentary canine. Had it 
been known by its jaws only, it would have been impossible 
to predicate from them its arboreal habits and adaptations, 
