384 Correspondence — Mr. John Miller. 



Since then the district has been traversed by Mr. Gregory, to 

 whose journal as well as to that of Leichhardt your readers are 

 referred. The Peak Downs are now settled, and a considerable 

 population have been digging gold on Theresa Creek and in other 

 places, and mining for copper has made advances to the westward at 

 Mount Drummond. 



Some time ago my attention was invited to a statement made by 

 the Gold Commissioner there, to the effect that a " Tertiary Biver" 

 had been discovered, and I was requested to examine the facts 

 alleged. On breaking up a vast amount of the pebbles and boulders 

 said to have been found in this " Tertiary Eiver," I discovered that 

 there was no clear evidence of anything that could be called Ter- 

 tiary ; but that they were pebbles of probably Quaternary accumu- 

 lation, consisting of Silurian, Carboniferous, and Secondary rocka 

 with the igneous rocks of the neighbourhood, which latter may be in 

 part of Tertiary age. 



In some of the creeks running more to the south-eastward from 

 the Peak Downs, and like Theresa Creek, belonging to the Mackenzie 

 Eiver system (e.g., Crinum Creek), occur bones of Trionyx and Cro- 

 codile. A year or two ago I forwarded some of these to my friend 

 Professor Huxley, whose determination I have not yet received. 



The naked fact of the discovery of Dinornis in this country is of 

 some value as to Geological inferences. 



I may add, in conclusion, that I look forward to further discoveries 

 in the vast accumulations of drift that encumber some of the localities 

 in the neighbourhood of the rivers watering the Leichhardt district, 

 where, among other relics, are those of the Carboniferous formation 

 which now presents only the wreck of a mass of strata that once 

 must have been nearly continuous over an area comprising several 

 degrees of latitude and longitude on one side or other of the Tropic 

 of Capricorn. W. B. Clakke, F.G.S. 



St. Leonard's, New South Wales, 

 19th May, 1869. 



p.g, — I have omitted to mention, that in the collection I exhibited 

 at Paris in 1855, No. 49 consisted of Osseous breccia (Bird bones) 

 from the Coadrigbee Cavern, in New South Wales. So, Dinornis, 

 though new, is not the first of its order. 



THE SO-CALLED HYOID PLATE OF ASTEROLEPIS. 

 Sir, — It may gratify the workers in the Old Eed Sandstone 

 to learn that I have solved the puzzle of the so-called Hyoid 

 plate of Asterolepis. It is in reality a Dorsal plate fitting on 

 immediately behind the ''Cranial Buckler" in nearly the same 

 position as that occupied by the Dorsal plate of the Goccosteus. I 

 have succeeded in obtaining two fine specimens of the head of the 

 Asterolepis with these plates in their proper positions, from the 

 Great Flag Deposits of Caithness, and I hope to be able to lay them 

 before the Geological Society of London in the course of the next 

 winter. John Miller. 



27, Bloomsburt Street, Bedford Square, 

 London, lOt/i July, 1869. 



