the banks of New-Year’s Creek as suddenly as they had disappeared after we left the marshes, and grew along the line of the Darling to unusual size.  But it is remarkable, that, even in the midst of the marshes, the blue-gum trees were strictly confined to the immediate flooded spaces on which the reeds prevailed, or to the very beds of the water-courses.  Where the ground was elevated, or out of the reach of flood, the box (unnamed) alone occupied it; and, though the branches of these trees might be interwoven together, the one never left its wet and reedy bed, the other never descended from its more elevated position.  The same singular distinction marked the acacia pendula, when it ceased to cover the interior plains of light earth, and was succeeded by another shrub of the same species.  It continued to the banks of New-Year’s Creek, a part of which it thickly lined.  To the westward of the creek, another species of acacia was remarked for the first time.  Both shrubs, like the blue-gum and the box, mixed their branches together, but the creek formed the line of separation between them.  The acacia pendula was not afterwards seen, but that which had taken its place, as it were, was found to cover large tracts of country and to form extensive brushes.  Many other peculiarities in the vegetation of the interior are noticed in the body of this work, but I have thought that these more striking ones deserved to be particularly remarked upon.

Geological features.

If we strike a line to the N.W. from Sydney to Wellington Valley, we shall find that little change takes place in the geological features of the country.  The sand-stone of which the first of the barrier ranges is composed, terminates a little beyond Mount York, and at Cox’s River is succeeded by grey granite.  The secondary ranges to the N.W. of Bathurst, are wholly of that primitive rock; for although there are partial changes of strata between Bathurst and Moulong Plains, granite is undoubtedly the rock upon which the whole are based:  but at Moulong Plains, a military station intermediate between Bathurst and Wellington Valley, limestone appears in the bed of a small clear stream, and with little interruption continues to some distance below the last-mentioned place.  The accidental discovery of some caves at Moulong Plains, led to the more critical examination of the whole formation, and cavities of considerable size were subsequently found in various parts of it, but more particularly in the neighbourhood of Wellington Valley.  The local interest which has of late years been taken in the prosecution of geological investigations, led many gentlemen to examine the contents of these caverns; and among the most forward, Major Mitchell, the Surveyor-General, must justly be considered, to whose indefatigable perseverance the scientific world is already so much indebted.