16 PROF. T. W. E. DAVID & MR. E. F. PITTMAN [Feb. 1899, 



3. On the Paleozoic Eadiolaetan Eocks of New Softh Wales. 

 By Prof. T. W. Edgewoeth David, B.A., F.G.S., and E. F. 



PiTTMAN, Esq,, Government Geologist, N.S.W. (Eead November 



9tb, 1898.) 



[Plates II-VII.] 



Contents. 



Page 



I. Introduction 16 



II. Localities 17 



III. Stratigraphy of the Radiolarian Rocks 18 



IV. Chemical Composition 31 



V. Microscopic Characters S3 



VI. Conclusions 36 



I. Introduction. 



The discovery of casts of radiolaria in Devonian rocks in New 

 South. Wales was made by one of us in 1895.^ It resulted from a 

 systematic microscopic examination of some of the red jaspers of 

 New South Wales, in the belief that they were very possibly of 

 deep-sea origin, and therefore likely to contain radiolaria, as was 

 suggested by the field-evidence, as interpreted elsewhere by one of 

 us." At first only chalcedonic casts of radiolaria were observed in 

 the jasper. 



Early in 1896 one of us (T. W. E. David), when on a visit to 

 England, was shown, through the courtesy of Mr. J. J. H. Teall, 

 P.P. 8., a number of carefully-prepared micro-sections of the Ordo- 

 vician (?) radiolarian cherts from MuUion Island, off the coast of 

 Cornwall, and from the Culm of Devon, as well as from the red 

 jaspers of the Antarctic Continent. A collection of radiolarian 

 rocks was also contributed by Dr. Hinde, chiefly from the Culm of 

 Devon and the Ordovician (?) of Mullion Island, for comparison with 

 Australian rocks ; and this collection subsequently proved of great 

 value in identifying the radiolarian rocks about to be described 

 from New South Wales. Work on these latter was resumed at the 

 University of Sydney during 1896, with the result that the black 

 cherts of lenolan were found to yield better results than the red 

 jaspers of the New England District of New South Wales. 



In September of the same year one of us (T. W. E. David) found 

 that at Tam worth, in New South Wales, certain lenticular beds of 

 siliceous limestone were not only composed chiefly of radiolarian 

 tests, but also contained numerous forms with the original siliceous 

 skeleton in a fair state of i3reservation, as was obvious from an 

 examination of the weathered exterior with a pocket-lens. A 

 preliminary note on this discovery was published in the Proceedings 

 of the Linnean Society of New South Wales. ^ 



1 Proc. Linn. Soc. N.S.W. ser. 2. vol. xi (1896) p. 561. 



2 Ibid. ser. 2, vol. viii (1893) p. 594. 



3 ^id. ser. 2, vol. xi (189G) pp. 553-57 & pis. xxxvii-xxxviii. ^ 



