Steered an average south-east course up the river from 6.40 a.m. till 1.0 p.m., when we camped at some pools of water in a side channel of the river, where it was divided by a hillock of slate-rock. The country is inferior in quality, the flats narrowing to an average of half a mile with very dry and thinly scattered tufts of grass. The bed of the river is better defined, and formed at times a single channel 250 yards wide, dry and sandy, as water was only once seen during the day. Low rocky ridges of sandstone gradually approached its banks, and near the camp porphyry, slate, and coarse granite formed detached hills 50 to 100 feet high, seeming to indicate an approach to the ranges in which the stream takes its rise. Latitude by a Cygni 18 degrees 15 minutes 21 seconds. GRANITE, PORPHYRY, AND SLATE. 28th September (Sunday). Walked out from the camp to a low hill about one mile south-south-east. It was composed of granite at the base and capped with horizontal strata of sandstone, some of the beds containing large water-worn pebbles, and the superstratum highly ferruginous. To the south-west of this hill the rock was slate, the strata nearly vertical; the strike north and south, but much contorted, and large pebbles of porphyry, quartz, slate, granite, sandstone, and agate formed banks in the bed of the river. The country, as seen from the hill, was generally level in appearance, but consisted of numerous low ridges and detached hills of granite, with sandstone on the summits. The valley of the river extended to the east and south, and a large branch appeared to join from the south about ten miles lower down, as a valley and some ranges of hills trended in that direction. The whole face of the country had an arid and desolate aspect, as there were no large trees except along the principal watercourses, and many of the hills appeared destitute of any other vegetation besides small acacias and scrub trees, the bare rock showing through its scanty covering. 29th September.