At nine miles we crossed some granite rocks, evidently a part of the ridge of Tarratta, thus exhibiting a uniformity in the granite with the general direction of other ridges, which is about north-north-east.  The strike is between north and north-east; the dip in some places being to the west, and in others to the east, at great inclinations.  The ridge of Kalingalungaguy consists of quartz, clay-slate, and the ferruginous sandstone, but I observed in the bed of the river a trap-dyke extending to the Bolloon ridge.  Of the few low hills about the Lachlan it may be observed that they generally range in lines crossing the bed of that river.  Mount Amyot is a ridge of this sort, being connected to the southward with Mount Stewart and Nyororong; and to the northward with the high ground separating the Bogan from the Goobang; the latter creek also forcing its way through the same chain on its course westward.  Mounts Cunningham, Melville, and the small hills about them on each bank belong to another system of ridges of similar character, but more broken up; and the range of Kalingalungaguy with that of Bolloon form a third, also intersected by the river.

OF THE PLAINS IN GENERAL.

The plains appear to be divided into several stages by these cross ridges, which may have shut up the water of high floods in extensive lakes during the existence of which the deposits formed the surface of the present plains.  Loose red sand also constantly forms low hills on the borders of these plains; and it seems to have been derived from the decomposition of the sandstone, and may be a diluvial or lacustrine deposit.  Blue clay appears in the lowest parts of the basin, and forms the level parts of the plain, with concretions of marl in thin layers.  This has every appearance of a mud deposit; but its depth is greater than the lowest part visible in the channel of the river.  The parallel course of small tributaries joining rivers, which seem to be the middle drain of extensive plains, may have been marked out during the deposition of the sedimentary matter as tributaries, on entering the channel of greater streams, immediately become a portion of them; hence it is, the general inclination being common to both, that such tributaries do not cross these sediments of floods now termed plains in order to join the main channel or river now remaining.

CHARACTER OF THE GOOBANG AND BOGAN.

Thus the Goobang, on entering the valley of the Lachlan, pursues a parallel course until the ridge from Hurd’s peak confines the plain on the west and turns the Goobang into the main channel.  The Bogan, on the opposite side of the high land, may be said to belong to the basin of the Macquarie, although it never joins that river, but merely skirts the plains which, below Cambelego, may be all supposed to belong to the original bed of the Macquarie.  Throughout its whole course of 250 miles the left bank of the Bogan is close to low hills, while the right adjoins the plains of the