Nearly the whole of interior Australia, including Western Queensland, is one vast cemetery of extinct and fossilised species, scattered along the surface, or buried deep in cement or drifts, and in clays hidden beneath the present surface formation. The open plains of the Upper Flinders disclose great deposits of marine fossil shells, belemnites and ammonites, and also remains of extinct animals. On the Lower Leichhardt River, in the Gulf of Carpentaria, forty or fifty feet beneath the alluvial deposits forming the banks of the river, and firmly embedded in the hard cement, which is an ancient drift formed of water-worn stones in an ironstone clay, are found the bones of innumerable extinct gigantic species of animals that found sustenance and multiplied in enormous numbers over the Gulf country in some far back pre-historic age. On the Walsh River are found large numbers of fossils, mostly shells of the ammonite species. The bones that have been buried for countless ages in these ancient drifts are well preserved, and are not very dissimilar in appearance to the bones of animals dying recently on the surrounding plains, although they are completely fossilised and changed into the appearance of stone. The utter extinction of these gigantic species, comprising diprotodon, nototherium, and zygomaturus, and other species, grasseaters and flesheaters alike, can only be accounted for by a great change of climate, and great and long-continued droughts, reducing the herbage and causing the remaining living animals to crowd into the drying-up lagoons and lakes, there to become bogged in thousands, and die as the stock die in the waterholes after a long drought. Some of the fossils are those of animals of a gigantic size, much larger than any existing native animals; the teeth found are twice the size of an ordinary bullock's, and the jaws carrying them are of enormous size and strength. There are remains of alligators over thirty feet long, and turtles of much greater dimensions than any existing in the present day. The vegetation in the marshes and territory forming North Queensland must have been of a luxuriant and tropical description in those days to have supported such large types of marsupials--animals that would require a more abundant moisture, larger rainfall, and heavier foliage, than are now to be found on the western slopes of the ranges. Deeply interesting is the study of the ancient forms of life that roamed over the densely-wooded marshes of the interior, when the flora represented a type found now only along the rich alluvial banks of the rivers on the east coast. GEOLOGY OF QUEENSLAND.