GLACIAL C0XDIII02JS IN THE PALEOZOIC BRA, ETC. 263 



defined epoch. The time has not yet come for the correlation of 

 rocks by means of their fossil contents ; and this is especially the 

 case with deposits which seem to hold a position intermediate 

 between the Palaeozoic and Mesozoic series. 



Mr. De Range admitted the important testimony adduced in sup- 

 port of the notion of the occurrence of Glacial epochs in Paloeozoic 

 times. But he wished to ask the author how he proposed to explain 

 the presence, throughout the extreme northern regions, of Silurian, 

 Devonian, and Carboniferous rocks, containing fossils identical with 

 those obtained in similar rocks in Europe. At the time of the 

 deposition of the Carboniferous Limestone, the Lias, and Oolites, 

 there seems to have been a continuous sea over the North Pole, 

 There was no evidence in these rocks of difference of temperature ; 

 the conditions seem to have been the same until we arrive at the 

 Cretaceous epoch, in which indications of climate first appear. 



The Atjthok, in reply, admitted that some of his points were 

 fairly open to question, but he begged to say that upon these he had 

 by no means pretended to speak decidedly. With regard to the 

 change of position of the earth's axis, he had remarked only that this 

 explanation had been suggested. He was quite prepared to join 

 issue with Mr. Carruthers on the question whether plants or marine 

 animals should decide as to the age of the deposits referred to. 

 Prof. M'^Coy, who thought the plants Mesozoic, was convinced as to 

 the Carboniferous age of the marine fossil animals in Australia : so 

 also were Prof. Morris and Prof. De Koninck. He maintained that 

 there is no knoAvn instance in which marine animals referred to 

 a certain age in one place are found differently arranged elsewhere, 

 whereas with plants the case is quite otherwise. With regard to the 

 doubts raised as to the pebbles and boulders being transported by 

 glacial action, he said that such masses, sometimes measuring six 

 feet in diameter, occurred scattered through a very fine silt, and he 

 knew of no other agency than that of ice by which boulders of that 

 size could have been so deposited. 



Q. J. G. S. No. 167. 



