Our very limited knowledge of the Flora of this vast continent (excepting of a part east of longitude 144 degrees, and included between the parallels of 31 and 35 degrees in New South Wales) is entirely confined to the vegetation of its immediate shores, upon every distinct coast of which, landings, more or less frequent, and under various circumstances, have been effected; although of all, very considerable portions remain unexplored, and of the line of West Coast (properly so denominated) the shores of Shark’s Bay, and some few parts south of it, have alone been scientifically investigated.  The interior within the tropic remains entirely in obscurity; the continental defect of a want of large streams having a distant source, to aid a penetration to the internal parts of the country, together with other effectual obstacles, draw at present a veil, and forbid all research into its Natural History and character, which will not be removed for very considerable periods (perhaps ages) yet to come!

It was the general remark made during a former expedition in the interior of New South Wales, that no absolutely entire change takes place in the vegetation east of the meridian of the new settlement named Bathurst; but that the plants of the coast were more or less frequent at a hundred and fifty miles from the sea, although in a country estimated at about two thousand feet above its level.  Having to this circumstance added a remarkable and obvious sameness (arising from an extensive dispersion) of a vein of vegetation in a large tract of country, it may be inquired, how far these facts might, when applied to other parallels, identify a certain portion of the Flora of the interior, and that of the sea-coast in the same latitude; or, in other terms, how far the botany of the coast indicates the general feature of the vegetation to a certain limit, in the interior on the same parallel?  Favourable opportunities were afforded me, to compare the vegetation of opposite coasts within the tropic, at the eastern and western extremes of a particular parallel; and the results of such a comparison identified many species on the two coasts.  I have annexed a list of those plants that are common to the North-west and East Coasts in and about the parallel of 15 degrees South, from a contemplation of which, together with the above remarks, and a further comparison of the species with those of the shores of the Gulf of Carpentaria, through which that degree of latitude passes, might not a general idea of some portion of the Flora of the expanse of intermediate interior (far beyond the reach of actual investigation) be presumed?

A few observations relative to the geographical range of certain genera and species, hitherto considerably circumscribed, will close this notice.