The estuary became narrower here, and shortly after seeing these natives we came upon a river running into it from the eastward; its mouth was about forty yards wide, the stream strong, but the water brackish, and it flowed through a very deep ravine, having steep limestone hills on each side: many wild-fowls were on the river, but we could not get a shot at them. Being unable to ford the river here we followed it in a south-east direction for two miles, and in this distance passed two native villages, or, as the men termed them, towns, the huts of which they were composed differed from those in the southern districts in being much larger, more strongly built, and very nicely plastered over the outside with clay and clods of turf, so that although now uninhabited they were evidently intended for fixed places of residence. This again showed a marked difference between the habits of the natives of this part of Australia and the south-western portions of the continent; for these superior huts, well marked roads, deeply sunk wells, and extensive warran grounds, all spoke of a large and comparatively-speaking resident population, and the cause of this undoubtedly must have been the great facilities for procuring food in so rich a soil. MOUNT VICTORIA AND MOUNT ALBERT. We now came to two very remarkable hills bearing north-east of us and distant about three miles, which I have named Mount Victoria and Mount Albert. They lay about one mile apart, and were of the form shown in Illustration 2, which will give a good idea of the flat-topped hills hereabouts. THE HUTT RIVER. The river still ran in a deep wooded valley bordered by rich flats, high hills lying both to the right and left of our line of route. Two miles and a half more on a course of 135 degrees brought us out on some gravelly barren plains, and just before coming to these, and in passing through a scrub, we raised a flight of white cockatoos, of a species new to me. One of the men got an ineffectual shot at them. FIRST HILLS OF THE SOUTHERN IRONSTONE FORMATION. After traversing these plains for two miles in a south-east direction we came upon a valley through which flowed a branch of the river we had this day discovered, running in a bed of fifty yards across, and having in its centre a rapid stream falling in small cascades; it appeared at times subject to extensive inundations, and here its course was through barren plains covered with rocks piled up in strange fantastic masses, and the bed was composed of that kind of red sandstone which at Perth is called ironstone; this being the farthest point north at which I have remarked it.