48 NOTE ON THE DISCOVEKY OF ORGANIC REMAINS, ETC. 



seven species having been recognised, as will be seen from two 

 important papers by Mr. Etlieridge * and Professor Tate.f As 

 to the classification of the Palaeozoic rocks of this region, there 

 is a wide divergence of opinion among the geologists who have 

 written on the subject, viz., Mr. H. Y. L. Brown,]: Dr. Charles 

 Chewings,|| and Professor Tate.§ Mr. Brown and Dr. Chewings 

 recognise not only a Silurian, but a Cambrian ; while Professor 

 Tate denies the existence of a Cambrian in Central Australia, 

 and divides the district between Pre-Cambrian and Ordovician 

 (Lower Silurian). Professor Tate does not, however, refer to 

 the discovery by Mr. Brown, at Alexandra Station, of a portion 

 of a trilobite, which Mr. Etheridge^i says " appears to be, with- 

 out doubt, an Olenelhis, and therefore indicative of Cambrian 

 rocks." 



It is reasonable to suppose that the Queensland Orthocera- 

 tites will turn out to belong to the same horizon (Ordovocian), 

 which has yielded fossils of the same class in the adjacent parts 

 of South Australia. Now there can be little doubt that although 

 the Orthoceratitidif. range from Cambrian to Triassic, we have 

 here fossils which are at all eveiits much older than the oldest 

 Queensland formation hitherto proved to be foniliferous, viz : — 

 the Burdekin Beds (Middle Devonian), and the specimens now 

 exhibited are the oldest organic remains yet discovered in 

 Queensland. Mr. Coghlan, to whom the credit of the discovery 

 belongs, promises to make a further collection. 



* On Additional Silurian and Mesozoic Fossils from Central Australia. Adelaide. 

 By authority : 1893. 



I Report on the Work of the Horn Scientific Exijedition to Central Australia ; Part 

 III. — Geology and Botany. London and Melbourne, 189B 



X Reports on Coal-bearing Areas in neighbourhood of Leigh's Creek, &c. Adelaide. 

 By authority: 1891. Further Geological Examinations of Leigh's Creek and Hergott 

 Districts, &c., Adelaide. By authority : 1891. 



W Geological Notes on the Upper Finke Basin. Transactions, Royal Society, South 

 Australia, XIV., 247. Notes on the Sedimentary Rocks in the McDonnell and James 

 Ranges. Transactions Royal Society, South Australia, XVIII., 197. 



§ Horn Expedition, ut siq'ra. 



% In Appendix B to Mr. Brown's Report on Northern Territory Explorations. 

 Adelaide. By authority : 1895. 



