president's address. 1217 



the Taupo Zone, N.Z., and before any intelligible reports by com- 

 petent observers had reached us, I drew up a sketch, p. 513, of the 

 Geological features of the district, chiefly from Hochstetter's 

 Atlas, and ventured upon some speculation as to the future 

 development of volcanic action in that region, which still awaits 

 fulfilment. I still hold however, the same opinion, and think it 

 probable that Rotor ua and Rotomahana with the other lakes of 

 that system will gradually after many periods of disturbance sink 

 into the quiescent condition of Lake Taupo. Having detected 

 in a fragmentary fossil from Biloela (Cockatoo Island), Port 

 Jackson, the characters of a lateral thoracic plate of a Laby- 

 rinthodont, ( Mastodonsaurus ?), I put together some consider- 

 ations as to the presence of Labyrinthodont Fossils in the 

 Hawkesbury rocks, and the conclusions to which it would seem to 

 lead us, both as to the age of the Hawkesbury-Wianamatta System, 

 and as to the Geographical condition of that period, pp. 931, 1113. 

 A further discovery of a small but fairly perfect fossil of a youno- 

 Labyrinthodont having been subsequently made near Gosford, 

 Brisbane Water, I gave a full description of it, p. 1175, with further 

 observations upon the character of the formation, and being unable 

 to refer it to any hitherto described form, assigned to it the provi- 

 sional title of Flatyceps Wilkinsonii. 



The Journal and Proceedings of the Royal Society of N.S.W. 

 for 1885 contains as follows : — 



1. The President, H. C. Russell, B.A., F.R.A.S., in his address 

 at the opening of the Session, May 6, besides extraneous matter, 

 deals with many points of local scientific interest, as e.g., the 

 Longitude of Sydney ; the question whether our coast is undergoing 

 elevation or subsidence, the relation between the great Rain and 

 Dust Storms of the Interior, and the oscillations of level in the 

 waters of Lake George. 



The Longitude of Sydney, as determined by the latest telegraphic 

 observations, is lOh. 4m. 49 -55s., a result which it seems worth 

 while to quote. The evidence as to elevation or subsidence of the 



