into a beautiful kind of fretwork (See volume 1) of more compactness than
the surrounding mass. In most places about the neighbourhood of
Fremantle, shells are found of the existing species along the coast,
firmly impacted in its substance, particularly a large species of
buccinum, as well as the strombus. This calcareous formation has been
traced as far north as Shark's Bay; it crosses over to the Abrolhos
Group, there frequently lying over a coral formation, and forming in many
places cavities of a cylindrical figure, of some few feet in depth. Beds
of clays, varying in quality and colour, are to be met with on sandy
margins, containing particles of gypsum.

On the Darling Range is found a red cellular structure capping the
granite, assuming all the appearance of having been subjected to fire; it
extends also in the low country about that
neighbourhood.

Slate of a primitive character is found on the Canning River. The
mountain chain or Darling Range runs nearly in the direction of north and
south. On the eastern side of it, close to the base, are several groups
of isolated conical hills, from a half to one mile apart, extending from
the William River to the Tugee District, a distance of about one hundred
and twenty miles, bearing on their summits strong evidences of ignition.
The country farther on to the eastward falls into sandy plains, similar
to those on the western side, and intersected by watercourses; during the
summer, pools remain, and at that time become remarkably salt. On the
mountains, as well as on the plains, scattered pebbles in patches are to
be met with; they appear to contain iron, being highly magnetic.

SAIL FROM SWAN RIVER.