Whilst in this locality I may take the opportunity of introducing a few notes on the geological formation of the country in the neighbourhood of Swan River, furnished by Mr. Bynoe: The most remarkable feature is the absence or scantiness of the secondary and transition rocks; all the tertiary appears to be of the newest kind, and to lie in juxtaposition with the primary. This character forms the sandy margin from the Darling Range, or chain of granite hills, nearly 2000 feet high to the sea, in the immediate vicinity of which the sand is bounded by a calcareous form of limestone, and, where jutting into the sea and forming perpendicular or overhanging cliffs, the faces are thrown 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.