Veins of calcareous spar and of quartz were again observed. I ascended a lofty hill, situated about a mile and a half to the west of our encampment, and found it composed of felspathic porphyry, with a greyish paste containing small crystals of felspar; but, in the bed of the river, the same rock was of a greenish colour, and contained a great number of pebbles of various rocks, giving it the aspect of a conglomerate; but recognisable by its crystals of felspar, and from its being connected with the rock of the hill. From the top of the hill, which is wooded with a silver-leaved Ironbark, I saw a very mountainous country to the N.N.W. and northward, formed into detached ranges and isolated peaks, some of which were apparently very high; but to the north-west and west no ranges were visible. A thunder-storm threatened on the 4th, but we had only some light showers: the morning of the 5th was very hot, and the afternoon rainy. Wind from north and north-east. Nights clear. April 6.--We travelled about ten miles N. 35 degrees W. over a ridgy, openly timbered, stony and sandy country, and crossed several sandy creeks, in which a species of Melaleuca, and another of Tristania were growing. No part of the country that we had yet seen, resembled the northern parts of New England so much as this. The rock was almost exclusively granitic isolated blocks; detached heaps, and low ridges composed of it were frequently met with in the open forest. We passed two small hillocks of milkwhite quartz; fragments of this rock, as well as of calcareous spar, were often observed scattered over the ground. The river here made a large bend to the northward, still keeping parallel to Robey's Range, or a spur of it; and, when it again turned to the westward, another fine high range was visible to the north by east and north-east of it; which I named "Porter's Range," in acknowledgment of the kindness of another of the contributors to my expedition. Its latitude is about 20 degrees 14 minutes. April 7.--Travelled about ten miles N. 70 degrees W. The country became more level, more open, and better grassed; the gullies were farther apart, and headed generally in fine hollows. Two large creeks joined the river from the westward; and a still larger one came from the northward, and which probably carries off the water from the country round a fine peak, and a long razorback mountain which we saw in that direction. North-west of Porter's Range, and between it and the razorback, were two small peaks. The timber is of the same kind, but larger. The poplar-gum was more frequent, and we always found patches of fine grass near it; even when all the surrounding Ironbark bark forest was burnt. The large clustered fig-trees were not numerous along the river; we perhaps passed from three to five in the course of a day's journey; though young ones, without fruit, were often seen.