partially filled with firm level earth which was water-worn at the brink,
its surface being about three feet higher than the water. This was
surrounded by a narrow beach of soft white mud or clay in which we found
no change on digging to the depth of several feet.

GREEN HILL LAKE.

The green hill was the highest of several semicircular ridges whose forms
may perhaps be better understood by the accompanying plan.* There was a
remarkable analogy in the form and position of all these hills; the form
being usually that of a curve, concentric with the lake, and the position
invariably on the eastern or north-eastern shores, a peculiarity I had
previously observed not only in the lakes near the banks of the Murray
but also in others on the Murrumbidgee and Lachlan where the ridge
consisted of red sand. The country on the western shore of these lakes
is, on the contrary, low and wooded like the surrounding country. In such
hills concretions of indurated marl frequently occur, but the earth they
consist of is sometimes light-coloured, in other cases very dark, like
the soil from trap-rock, and the ridges beside the lakes on the
Murrumbidgee, consisted of red sand.

(*Footnote. Having modelled this feature I have the satisfaction of
presenting to the reader the first specimen of a plan of ground worked
from a model by the anaglyptograph, an important invention recently
perfected in this country by Mr. Bates and likely to be of very
considerable value in the representation of the earth's surface under the
skilful management of Mr. Freebairn.)

MITRE LAKE.

The water of Mitre Lake was also salt,* but there were numbers of ducks
and black swans upon it. The western shore was low, and the soil where it
had been thrown up in the roots of fallen trees was nearly as white as
chalk. A gray rather fine quartzose sand occurred in some places; and
along the water's edge a very minute shell had been cast up in
considerable quantities by the waves.** The hills to the eastward of this
lake were arranged in a crescent around the basin, but this being
composed of a number of hills almost separate from each other had a less
regular or uncommon appearance, although they were apparently the remains
of a curve equally as symmetrical as the others. The basin of this lake
was very extensive but partly filled on the side next the low hills by a
level tract of dry land covered with a brown bush (Salicornia arbuscula
of Brown); and the concentric