1118 ON THE BILOELA LABYRIKTHODONT, 



in the alternate hemispheres in such a manner that equable warmth 

 in the Northern or Southern was contempoiary with the most 

 extreme inclemency in the opposite. 



The particular horizon in which the characteristic fossils may be 

 looked for is, as is shown by the Biloela remains, nearly at sea-level 

 along the coast. It is at the same level that the action ot river 

 ice has been detected by Mr. Wilkinson. (Report, &c, 1882, 

 p. 53.) That quantities of: fern fragments, with their tissues still 

 woody and elastic, are everywhere to be met with in the intercalated 

 shales ; that Ottelia prceterita, was found on the shores of the 

 Parramatta River ; and that thick beds of ferruginous con- 

 cretionary sandstone, as seen at all levels, from that of the sea 

 to the heights of Waverley, Randwick, and North Head, are 

 worked for road metal, or gravel, is all evidence to the same effect. 

 Now if we follow this horizon to the westward, we observe the 

 strata dipping towards the Nepean fault, at a small angle, indeed, 

 but unmistakably. From the first slope of the ascent of the 

 Blue Mountains, where the still incoherent sands have been bent 

 downwards towards the East, without other disturbance than that 

 caused by the necessary sliding of bed over bed, and certainly 

 before their consolidation into what is ordinarily known as rock, 

 we find a continual rise to the westward ; reaching at last its 

 culmination in the unabraded summit levels of sandstone which 

 have been protected from erosion by the basalt of Mount Tomah, 

 Mount Wilson, Mount King George, and Mount Hay. At Mount 

 Piddington, near Mount Victoria, we find Thinnfeldia, and likewise 

 evidences of ice, in abundance. There too, and more particularly 

 at Katoomba, we find the ferruginous quartz conglomerate, which 

 is repeated in identical form in Clark Island in Port Jackson, and 

 elsewhere on the coast. 



This I take to be the horizon of the fossiliferous beds of Biloela, 

 and it is along this plane that I should expect that more important 

 discoveries will yet be made. 



Nothing however can now upset the identification of our Hawkes- 

 bury (and probably Wianamatta) beds with the Trias of Europe 

 and India, 



