higher than that of the main channel, which still continued of pure sand--and was stamped all over with the prints of the feet of natives, kangaroos, emus, and wild dogs, We then turned again to the head of the lagoon, and took the following bearings of Arbuthnot's range: Mount Exmouth .......... E. 90 S. Centre Range ........... E. 35 E. Vernon's Peak .......... E. 20 S. From the head of the lagoon, the river appeared to enter a reedy hollow, shaded by a long line of flooded gum trees, and on proceeding to it, we found the banks ceased here altogether; and that a very considerable plain extended both to the right and the left, which cannot fail of being frequently laid under water. LAGOONS AND CREEKS OF THE CASTLEREAGH. On the following morning we moved the party to the lagoon, and, passing its head, encamped to the north of it; after which we again rode down the river in search of water. It continued to hold a straight and northerly course for about five miles, having a plain on either side. The reeds that had previously covered the channel then suddenly ceased, and the channel, contracting in breadth, gained in depth: it became extremely serpentine, and at length lost all the character and appearance of a river. It had many back channels, as large as the main one, serving to overflow the neighbouring country. We succeeded in finding a small pond of water in one of the former, hardly large enough to supply our necessities, but as it enabled us to push so much further on, we turned towards the lagoon, making a circuitous journey to the right, across a large plain, bounded to the north by low acacia brush and box. We struck upon a creek at the further extremity of the plain, in which there was a tolerably sized pond. It appeared from the traces of men, that some natives had been there the day before; but we did not see any of them. The water was extremely muddy and unfit for use. The lagoon at which we had encamped, was of less importance than we had imagined. JOURNEY DOWN THE RIVER. Whilst Mr. Hume led the party down the river, I rode up its northward bank, to examine it more closely. I found it to be a serpentine sheet of about three miles in length, gradually decreasing in depth until it separated into two small creeks. In following one of them up, I observed that they re-united at the distance of about two miles, and that the lagoon was filled from the eastward, and not by the river as I had at first supposed. The waters at the head of the lagoon were putrid, nor was there a fish in, or a wild fowl upon it. The only bird we saw was a beautiful eagle, of the osprey kind, with plumage like a sea gull, which had a nest in the tree over the tents. In turning to overtake the party I rode through a great deal of acacia scrub, and on arriving at the place at which I expected to have overtaken them, I found they had pushed on.