602 president's address. 



have been described by Professor McCoy. In New South Wales 

 Middle Devonian rocks are doubtfully represented by the Coodra 

 Yale and Cave Flat limestones, near the Murrumbiflgee, in 

 the Yass District, where remains of Coccostean fish have been 

 obtained. 



In Queensland the Burdekin forroation, of Middle Devonian 

 Age, is estimated by Mr. R. L. Jack to be upwards of 20,000 feet 

 in thickness, and comprises an ancestor of the Barrier Eeef of 

 Australia in the form of a massive bed of coralline limestone 7000 

 feet in thickness in places. Some of the sandstones in this forma- 

 tion are crowded with suncracks. A few beds of contemporaneous 

 volcanic ash are interstratified. The oldest known terrestrial plant 

 from Australasia [a Conifer (?)\ Dicranoiihyllum Australicutn^ 

 Dawson, has been discovered in the Burdekin strata. In the Kira- 

 berley District of Western Australia the late Mr. E. T. Hardraan, 

 the discoverer of the Kiraberley Goldfields, describes Devonian 

 rocks exceeding 10.000 feet in thickness. In New Zealand Captain 

 Hutton groups in his Takaka system all the sediments between 

 the Lower Silurian and Devonian, and assigns to this system, as 

 developed in Otago, the astonishing thickness of 100,000 feet, 

 that is about 19 miles. As the lowest of these strata are now 

 visible at the earth's surface, and do not show evidence, in spite 

 of their having been buried to such a depth, of having been 

 liquefied, they afford interesting proof as to the ]n'obable minimum 

 thickness of the earth's crust, and their evidence agrees fairly 

 well with that deduced from earthquake observations, wdiich show 

 that there is material in the earth's crust sufficiently solid to crack 

 and so produce vibrations at a depth of 20 and even 30 miles ; 

 in one observed case, in America (the Owen's Yalley earthquake), 

 of 50 miles. There is no evidence of any land having appeared in 

 New Zealand up to to the close of the Devonian Period. There 

 is a singular absence of conglomerates and all indications of 

 shallow water conditions. Indeed, in the next formation, the 

 Maitai, some of the red jasperoid claystones are thought by 

 Professor Hutton to represent abysmal deposits, the equivalents 

 of the red clays of modern deep oceans. 



