marsupial, and about the size of a rabbit, but is
greatly disproportioned, as all the Kangaroo tribe are, as regards the
hind and fore quarters. In colour this animal is a silvery grey, crossed
with dark coloured bars on the back.

9. PHALANGISTA VULPINA.--The Opossum.

Like the preceding, only one of these animals was seen or shot during the
Expedition; it was in one of the gum-trees, taking its silent and lonely
ramble amongst its branches, when the quick eye of Tampawang, my native
boy, saw him. It does not appear generally to inhabit the N.W. interior.
The present was a very large specimen, with a beautifully soft skin, and
as it was the only one noticed during a residence of nearly six months at
the same place, it was in all probability a stray animal.

10. VESPERTILIO.--Little black Bat.

This diminutive little animal flew into my tent at the Depot, attracted
by the light. It is not common in that locality, or any other that we
noticed. It was of a deep black in colour and had smaller ears than
usual.

* * * * * * *

BIRDS.

I have observed that a principal reason I had for supposing that there
was either an inland sea, a desert country, or both in the interior, was
from observations I had made during several expeditions, and in South
Australia, of the migration of certain of the feathered tribes to the
same point--that is to say, that in lat. 30 and in long. 144, I observed
them passing to the N.W. and in lat. 35, long. 138, to the north. Seeing,
on prolonging these two lines, that they would pass over a great portion
of the interior before they met, about a degree beyond the tropic, I
concluded that the nature of the intervening country was not such as they
could inhabit, and that the first available land would be where the two
lines thus met. It so happened that at the Depot, in lat. 29 1/2 and in
long. 142, I was in the direct line of migration to the N.W., and that
during our stay at that lonely post, we witnessed the migration of
various birds to that quarter, though not of all. This was more
particularly the case with the water-birds, as ducks, bitterns, pelicans,
cormorants, and swans,--we saw few of the latter, but generally heard
them at night passing over our heads from N.W. to S.E. or vice versu; but
we never afterwards found any waters which we could suppose those birds
could frequent in the distant interior. On Strzelecki's Creek a small
tern was shot, and on Cooper's Creek several s