places covered with oyster shells so little changed by time, as to appear
as if they had only just been thrown in a heap on the ground they occupy.

The general appearance of the country through which I had passed, and the
numerous deposits of fine sand upon the face of it, like sea dunes, still
more convinced me, that, when the events which had produced such a change
in the physical structure of the continent took place, a current of some
description or other must have swept over the interior from the
northward; and that this current had deposited the great fossil bed where
it now rests; for I cannot conceive that such a mass and mixture of
animal remains could have been heaped together in any other way. From the
outline of this bed, it struck me that some natural obstacle or other had
checked the detritus, brought down by the current, as sand and gravel are
checked and accumulated against a log or other impediment athwart a
stream, presenting a gradual ascent on the side next the current and a
sudden fall on the other. Such, in truth, is the apparent form of the
great fossil bed of the Murray. This idea, which struck me as I journeyed
down the river, was strengthened, when at a lower part of it I observed a
ridge of coarse red granite, running across the channel of the river, and
disappearing under the fossil formation on either side of it. It appeared
to me to be probable that this ridge of granite might rise higher in
other places, and that stretching across the current as it did, that is
to say from west to east, the great accumulation of fossil and other
remains had been gradually deposited against it, forming a gradual ascent
on the northern side of the ridge, and a precipitous fall upon the other.

I have already observed that at a particular point the rivers of the
interior, which I had traced on my first expedition, appeared to lose
their character as such, and that they soon afterwards ceased in some
extensive marsh, the evaporation and absorption over such extensive