166 Proceedings of the Royal Society of Victoria. 



Under the head of Devonian in New South "Wales the late Mr. 

 C. S. Wilkinson^ makes the following statement : — " Under this 

 head is classed an important suite of rocks, consisting of sand- 

 stones, conglomerates, limestones, and shales, the lower beds of 

 which are related by their fossils to the Silurian and the upper 

 beds to the Carboniferous. Consequently until their strati- 

 graphical relationship has been ascertained by actual survey, 

 some difficulty will be experienced in assigning definite limits to 

 these formations." Subsequently- Mr. Wilkinson remarks on the 

 high state of development of the class Actinozoa in the " Siluro- 

 Devonian Period" as compared with their remarkable diminution 

 in the Carboniferous and Permo-Carboniferous times. 



Siluro-Devonian seems to have crept in to stay, for we find 

 other references to it, and descriptions of new fossils from Silui^o- 

 Devonian rocks of New South Wales by Mr. R. Etheridge, 

 junr.^ 



With regard to Cambro-Silurian, here again we have more 

 than the one view as to its exact significance. The general use 

 of this is well expressed by Dr. Kayser.'* " It is now almost 

 universally admitted that the Cambro-Silurian rocks fall naturally 

 into three great divisions, each characterised by its own peculiar 

 fauna. Speaking broadly, Sedgwick applied the term Cambrian 

 to the two lower ; Murchison at first included in his Silurian 

 the two upper divisions, but ultimately took in a large part of 

 the lowest also. The greater number of geologists, perhaps, 

 apply the term Cambrian to the lowest division, and of Silurian 

 to the two upper." The oscillation of opinion on the use of the 

 general classificatory terms for the subdivisions of Lower 

 Palaeozoic even by our most eminent English geologists is very 

 great indeed, and may perhaps be best shown for our present 

 purpose by the following table copied from the above quoted 

 work : — 



1 Notes on the Geology of New South Wales, by C. S. Wilkinson, 1882, p. 42. 



2 A Monograph of the Carboniferous and Pernio-Carboniferous Invertebrata of New 

 South Wales, Part i., Coelenterata, by R. Etheridge, junr. ; Letter of Transmittal, by C. S. 

 Wilkinson, p. vii., 1891. 



3 On the occurrence of a Stromatoporoid allied to Labechia and Rosenella, in the 

 Siluro-Devonian rocks of New South Wales by R. Etheridge, junr., in the Records of the 

 Geological Survey, vol. iv., pt. iii., 1895, p. 134. 



i Text Book of Comparative Geology by E. Kayser, Ph.D., translated and edited by 

 Philip Lake, M.A., F.G.S., 1893, p. 29. 



