On visiting Hergott Springs, Mr. Waterhouse learnt that Mr. Burtt, whose station* is only a few miles distant, in opening these springs discovered some fossil bones, casts of which were forwarded to Professor Owen, who pronounced them to be the remains of a gigantic extinct marsupial, named Diprotodon Australis. (* Hergott Springs were only discovered and named by Stuart three years before, yet we now find a station close by them. The explorer is not far ahead of his fellow-colonists, as is well remarked by the Edinburgh Review for July, 1862: "Australian occupation has kept close on the heels of Australian discovery.") Bones of this animal have also been found in a newer tertiary formation in New South Wales. Mr. Waterhouse considers that a great tertiary drift extends over this part of the country, obscuring and concealing at no great depth below the surface many springs, which may hereafter be discovered as the country becomes better known. The Louden Spa is a hot spring arising out of a small hillock, and proceeds from the fissures of volcanic rock. This water is medicinal, but not disagreeable to the taste: the damper made with it was very light, and tasted like soda-bread. In his remarks on the second division Mr. Waterhouse states much that is valuable. He estimates the height of Mount Hay at two thousand feet, regarding it as the highest point of the McDonnell Range, which is the natural centre of this part of the continent. Mr. Waterhouse only saw Chambers Pillar from a distance, but he had an opportunity of examining a smaller hill of the same character, and found it to be composed of a soft loose argillaceous rock, at the top of which was a thin stratum of a hard siliceous rock, much broken up. "The isolated hills appear to have been at some remote period connected, but from the soft and loose nature of the lower rock meeting with the action of water, had arisen a succession of landslips. These have been washed away and others have followed in their turn; the upper rock, from being undermined, has fallen down and broken up, supplying the peculiar siliceous stones so widely distributed on parts of the surface of the country." The vegetation of this district is poor; the myall is scarce, but the mulga (Acacia aneura) generally plentiful. Both these shrubs are species of acacia, the myall being of much larger growth and longer lived than the mulga. Nutritious grass is seldom found except in the immediate vicinity of the creeks, and the scrubs are very extensive. Mr. Waterhouse collected a great number of specimens of natural history, but, from want of the convenience for carrying them, many of the more delicate objects were broken.