282 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 24, 



Quart, Journ, Geol. Soc. vol. xxiii. p. 7, suggesting that they were 

 " Rh^tic." 



A thorough examination of these by Charles Moore, Esq., F.G.S., 

 the results of which were detailed in Quart. Journ. Geol. Soc, vol. 

 xxvi., led him to the conclusion that the WoUumbilla beds have their 

 nearest representatives in the Oxford Clay. But it is possible that 

 fossils from different localities, or perhaps drift specimens, have been 

 mixed up, as he says " it is not easy to decide with certainty as to 

 the exact position of the fossils that come from WoUumbilla. The 

 Lias, the Great Oolite, the Oxford Clay, the Portland Oolite, and 

 the Cretaceous beds may each put in a claim ; but that of the Oxford 

 Clay appears to be the strongest." 



The Bungeworgari and Amby river-beds are considered by Moore 

 to be Cretaceous. This much then can be asserted, that all the 

 great plains of Queensland westward of the main coast-range con- 

 sist of subaerially decomposed Oolitic and Cretaceous shales, lime- 

 stones, and sandstones, or the river-detritus of such, redeposited on 

 their surface. 



That this portion of the Mesozoic system extends throughout the 

 whole of Central Queensland to Western Australia is also more than 

 probable, hidden, however, over large areas by " Desert Sandstone." 



The finding, by Stuart, of a Cytherea ? (first mentioned by Clarke) 

 on the Gregory river, a few miles north of Finnis Springs, and the 

 extent of marly plains similar in character to those on the Flinders, 

 the well-known occurrence of Cretaceous fossils in the Moresby 

 ranges, and of Oolitic in other parts of Western Australia, favour 

 this idea. We may look forward to the clearing-up of this point 

 when the collections of the South Australian Telegraph party are 

 described. 



The only variety in the lithological character of the Flinders- and 

 Thompson -river Mesozoic rocks, is the change from shale to fine- 

 grained sandstone in the alternating beds, the shale greatly pre- 

 dominating ; its line of bedding marked by thin bands and nodular 

 layers of argillaceous limestone. 



One other peculiarity in the strata forming the series is the pre- 

 sence at intervals of thin layers of limestone having the well-known 

 cone-in-cone structure. 



This has more the appearance of a chemical precipitate than a 

 mechanical deposit, and contains no fossils. Its analysis gave : — - 



CoNE-iN-coNE Limestone. 



Insoluble in hydrochloric acid 14'920 



Ammonia-precipitate 4"860 



Carbonate of lime 75"458 



Undetermined constituents 4'762 



100-000 



How far the Flinders and Thompson series have extended over 

 the dividing ranges is not yet thoroughly determined. 



On Pelican Creek, a tributary of Bowen river, near an out-station 



