July 23.--The weather continues remarkably fine and favourable to our progress over these plains. Our course to-day was chiefly through a thick brush of acacia and cypresses; a few trees of the eucalyptus and casuarina were intermixed. The marshy ground was not so frequent, and we effected between eight and nine miles, when we stopped on a small chain of ponds but now a running strean, doubtless having its rise in the marshy grounds a few miles south of us: its course was to the north. We saw and shot several unknown birds within these few days, but the botanical sameness continues. These ponds were named Morrissett's Ponds, after Capt. Morrissett, of the 48th regiment. July 24.--About a mile and a half from last night's station, we crossed another small stream similar in all respects to Morrissett's Ponds. Our course was alternately over wet flats and dry brushes; but in the latter we met with difficulties which we did not anticipate, namely, dry bogs of a most dangerous description; they are from thirty to forty yards broad, and the apparent firmness of their surface treacherously conceals the danger beneath. One was discovered before the horses were too far advanced to retreat, and by unlading them, we passed safely over. The horses were upon the other before we discovered the extent of our danger, and it was only by instantly cutting away their loads and harness, and by the exertion of all hands, that they were dragged out; but they were so exhausted by the struggles they had themselves made, that I found it would be highly imprudent to proceed farther, though we had only gone five miles and a half. Such of the horses as had not come up, their loads being carried over, crossed the bog half a mile higher, where the ground was somewhat firmer. We had this day the misfortune to find two of our horses much strained in their hind quarters. The soil of the brushes is in general a light, sandy loam; on the plains it is an alluvial mould, on a substratum of clay: the water on these plains is seldom deeper than the ankles, but travelling over them is very wearisome. Arbuthnot's Range was in sight during the whole day. The country was so generally level, that it was impossible to discern any inequality in it. The waters however, ran with a pretty brisk stream northerly.