April 22.--We travelled about nine miles west, making our latitude 19 degrees 12 minutes. Ranges ran parallel to the river at different distances: we left a very fine one to the south-west and south, from which the large creek we passed about two miles from our last camp, probably descends. Three miles farther, a river as large or even larger than the Burdekin, joins the latter from the westward and south-west-- the Burdekin coming down from the north-west. I was doubtful which of the two rivers I ought to follow; but finding, after a close examination, that the north-west branch was running, whilst the south-west one contained only large, long, but unconnected reaches of water, I determined upon following the north-west branch. I called the south-west branch the "Clarke," in compliment to the Rev. W. B. Clarke of Paramatta, who has been, and is still, most arduously labouring to elucidate the meteorology and the geology of this part of the world. About three miles above the junction, a creek of considerable size joined the Burdekin from the northward. Wherever the ridges approached the banks of the river, gullies which were scrubby at their heads, became numerous. After having encamped, I rode over to the "Clarke," to examine the intervening country. The flat along the Burdekin was about two miles and a half broad, and was skirted by silver-leaved Ironbark ridges. In approaching the Clarke, we came to a low basaltic range, which bounded its fine broad openly timbered valley to the northward. The bed of the river was formed by talc-schiste, in strata, the strike of which was from north by west to south by east, standing almost perpendicular, with a slight dip to the eastward. The stream was perpendicular on the line of striking. The pebbles in its bed were mostly basaltic, baked sandstone, conglomerate, quartz, sienite, and porphyry. I had observed the valley of this river from a high hill near our last camp, and had distinguished many headlands, which I now think were the bluff terminations of lateral basaltic ranges. The valley was bounded on its southern side by a long low range. The blue mountain parrot was very frequent near our camp. I have mentioned a small round eatable tuber, which I found in the basket of a native gin on the 2nd January. I here found it to be the large end of the tap root of a Potamogeton, or a plant nearly allied to that genus; I found it with another interesting water-plant, with foliated spikes of blue flowers, in a small water-hole near our last camp.