i8 9 6. NOTES AND COMMENTS. 83 



Creek, a locality from which a great number of the bones of 

 marsupials and other extinct animals of Tertiary or Post-Tertiary 

 age have been derived. Although time did not permit of a systematic 

 search for bones, a collection was made of the shells of fresh-water 

 Mollusca associated with them, of which little notice has hitherto 

 been taken. These molluscs do not furnish many species, although 

 individuals are incredibly numerous ; all the species, with one 

 doubtful exception, a Unio, are still extant in the same geographical 

 area, e.g., Corbicnla nepeanensis, Melania balonnensis, and Hadra jarvisiensis. 

 The question of age cannot, however, be settled until a larger 

 collection has been made. 



Upon certain grits and sandstones of Lower Cretaceous age 

 there occur at certain localities, such as Flinders and Whetstone 

 Station, curious markings, which are generally considered to have 

 been made by aboriginals in grinding their tomahawks. The 

 markings occur generally in groups up to five in number, and are 

 individually up to a foot in length. They diverge slightly at one end, 

 and are gathered into a bunch at the other. Mr. Jack points out 

 certain difficulties in accepting the usual explanation, and suggests 

 that the markings are the footprints " left on a beach sand by the 

 passage of some heavy five-toed animal and partly filled up by the 

 falling in of the sand." 



In the valley of the Claude River, there occurs a formation con- 

 sisting of grey shale, with which are intercalated beds of hard grey 

 calcareous sandstone and grey sandy limestone. The shales contain 

 numerous nodules of limestone, roughly cylindrical like segments of 

 the trunks of trees, but with rounded ends ; no organic nucleus has 

 been discovered in these nodules. The sandstones and more sandy 

 beds of the shales are full of large segments of silicified trunks of 

 trees, in one of which were counted 130 rings of growth. The whole 

 formation is absolutely unlike any other yet known in Queensland, 

 and, although the country where it occurs resembles the " Rolling 

 Downs," the age of the formation is possibly Permo-Carboniferous. 



There are many other points of scientific importance which it is 

 refreshing to find in a report that is professedly of a practical nature. 

 The report by William H. Rands, on the " Leichhardt Gold 

 Field and other Mining Centres in the Cloncurry District," which 

 has been sent to us from the Survey, appeals more purely to the 

 working miner. It appears that this area is likely to yield rich 

 results if those who prospect there can overcome the difficulties of 

 want of water and want of food. The former difficulty, at all events, 

 will best be grappled with if the colony will extend a generous 

 support to its energetic Geological Survey. 



The Origin of Slugs. 

 Lieut. -Col. H. H. Godwin-Austen and Mr. W. E. Collinge 

 have lately contributed a paper to the Proceedings of the Zoological 



