president's address. Gil 



This isolation extends even to the sea-fisli, to a certain extent. 

 Thoug'li the differences between Port Jackson and Port Philip as 

 regards temperature and situation are slight, 3'et the common 

 marine fishes are of different species. It is a remarhahle fact 

 also, that the Geology of the South and East Coasts are different. 

 In the East we have the main cordillera of our continent, which 

 varies but little in its character from Cape Howe to Cape York. 

 "\Vo have a central granitic axis with the usual porphj-ritic and 

 diabasic or dioritie djdces, and cappings. These metamorphie or 

 volcanic rocks are flanked by highlj'-inclined palaiozoic schists 

 and slates, Devonian rocks less inclined, altered, or not f ossilif erous 

 appear in places. These are succeeded by the upper and lower 

 coal measures. The whole are capped unconformably by almost 

 horizontal sandstones, known in New South Wales as the 

 Ilawkesbury formation. This is the order and character of the 

 range wherever I have visited or crossed it ; and this is the 

 sequence shown by all geological survey's. The Ilawkesbury 

 sandstone is fully developed in various places, and can be seen 

 in its best sections around the Endeavour Piver and on the upper 

 waters that flow into the Gulf of Carpentaria. On the Pacific 

 side of the range there are small outlines of the mesozoic rocks 

 in various places north of Cape More ton. They generally occur 

 on lowlands or where the main axis is less marked as a centre of 

 disturbance. These exceptions are so small that they do not 

 affect the general truth that our cordillera is paliieozoic in age, 

 and has been upheaved at the close of the palieozoic period. 



On the South Coast the Geology is quite different. There is 

 no main axis. A few isolated ranges crop up in different parts 

 of the coast. These are never of large extent, except in the case 

 of the range which begins at Cape Jarvis. The pahTOzoic 

 rocks are not absent, but they occupy quite an insignificant position 

 in comparison with the immense development of tertiary formations. 

 The methods applied to the Geological investigation of the 

 Eastern range are quite useless here. In palroontological research, 



