582 president's address. 



y. Carbonifero-Devonian or Uppkr Devonian. 



Rocks of tliis age, characterised specially hy Spir if era disjuncta, 

 Rhynchonella jjlf'Ui'odon, and a Pteronites^ which Mr. R. Etlieridge, 

 Junr., is now describing as a new species, P. Pittmcmi, have so 

 far been observed only in the Mount Lambie District of New 

 South Wales.^ 



In the type district at Mount Lambie they consist of a marine 

 and of a freshwater series, the latter being uppermost. No 

 unconformability, however, has been observed between the two 

 series, and Mr. Wilkinson grouped them together as Devonian. 

 The lower series consists of quartzites containing abundant fossils, 

 especially Spirifera disjuncta and Rhynchoneda pleurodon, reddish 

 purple shales, and beds of conglomerate, grit, and hard dark mud- 

 stones. The rocks of the upper series are chiefly argillites, shales, 

 muclstones, and reddish-purple shales, with bluish-grey felspathic 

 quartzite and white quartzite. The thickness of the whole series 

 is estimated by Mr. Wilkinson as about 10,000 feet. Possibly 

 the upper series may hf^reafter be referred to the CarV)oniferous, 

 and only the lower to Upper Devonian or Carbonifero-Devonian. 



Near Rydal a strong unconformability is observable between 

 the marine Permo-Carboniferous strata and tlie freshwater series 

 of the Upper Devonian, the latter dipping at angles of from 30° 

 to 40° to the E., 15° N. or W., 15° S. ; while the former has a 

 gentle north-easterly dip of not more than 4°. 



The base of these Upper Devonian rocks is not seen near 

 Mount Lambie, but on the road to the Jenolan Caves, six and 

 nine miles from the caves towards Mount Victoria, a coarse 

 conglomerate, perhaps representing the base of this series, appears 

 to rest unconfonnably on the Cave Limestone Series (Upper Silu- 

 rian), as has lately been observed by Messrs. W. F. Smeeth, J. A. 

 Watt, and myself. A Ileliolites and casts of crinoids have lately 

 been discovered by Mr. Voss Wyburd in this conglomerate. 



* Remarks oq the Sedimentary Formations of New South Wales, by the 

 Rev. W. B. Clarke. Fourth edition, 1878, pp. 17 and 22. And Geological 

 Map of the Districts of Hartley, Bowenfels, Wallerawang, and Rydal, with 

 Notes and Sections, by C. S. Wilkinson. By authority. Sydney, 1875. 



