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34 such be the case it would throw off water to the southward and westward. We have therefore on each side of the coast coloured "alluvial" in the accompanying chart, a probable rise of land, and an absence of the fresh water channels which are so abundant in that tract, which makes it probable that a great portion of the central region of New Guinea is drained by a river or rivers which disembogue on that "alluvial" coast. This would account for the vast body of fresh water we found there, not only keeping- the multitude of arms and channels that intersect the land full of fresh water, but affecting the water of the sea to a very great degree, so as almost to render it drinkable at particular times of the tide, at a distance in some places of 8 or 10 miles from the shore.

Before quitting the eastern coast of Australia I must mention one singular circumstance, namely, the occurrence throughout its whole extent from Bass's Straits to Torres Straits of pebbles of pumice, strewed over the flats just behind the beaches to the height of a few feet above high water mark. These pebbles were always well rounded, varying in size from that of nuts to pieces as big as the fist, and are frequently found in considerable abundance. They have never been seen floating nor left on the actual beach by the wash of the sea, except in a few instances where they may have been washed down from above by the rains. It is difficult to conjecture their origin, but they may have proceeded