ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 317 



is made, and the suggestion is put forward that they are 

 of the same age and magmatically related. 



The results obtained from this small collection are 

 sufficient to show that the whole official collection, con- 

 sisting of some hundreds of rocks is worthy of a fresh 

 examination in the light of the recent knowledge acquired 

 in the Western Australian goldfields. Presumably the 

 collection is in the possession of the Royal Society of South 

 Australia. 



Explanation of Plate XI V. 



Fig. 1. Banded norite, Eraser's Range, Western Australia. 

 Natural light. Magnified 15 diameters. 



2. Hornblende granite-gneiss, Blyth Range, Central 

 Australia. Crossed nicols. Magnified 15 diams. 



3. Granulite, Barrow Range, Central Australia. Natural 

 light. Magnified 15 diams. 



4. So-called tachylite, Cavanagh Range. Natural light. 

 Magnified 15 diams. 



5. Pyroxene-perthite in quartz dolerite, No. 14, Near 

 Depot 1. Crossed nicols. Very highly magnified. 



6. Hypersthene olivine dolerite. showing ophitic structure 

 of both olivine and hypersthene towards felspar. 

 No. 8, Hills near Camp 5, 20/6/91. Natural light. 

 Magnified 15 diams. 



