92 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 13, 



coast of Belgium runs parallel with the east and west range of the 

 Netherlands ; and such also, according to the line traced by M. Berg- 

 haus, is its direction across the continent of Europe. South Wales 

 presents a like east and west arrangement, and does not seem to have 

 been submerged. In the South of Ireland again, we have a district 

 where all the physical features are dependent on an east and west di- 

 rection ; and here again the drift beds, which are so widely spread 

 over the rest of Ireland to the northwards, are altogether wanting. 



The geographical aspect of the north-west part of Europe at the 

 period of the farthest range of the pleistocene sea would, according to 

 these \iews, be somewhat such as represented in the map*. The 

 northerly areas of insulation are taken from Prof. E. Forbes, and are 

 in perfect accordance with the pure geological evidence of the greatest 

 amount of depression which the north of this island presents. 



In this \iew I have considered all stratified wide-spread gravels 

 containing elephants' remains to be of the same period wiih the upper- 

 most pleistocene drift, whether the deposits contained marine shells 

 or not. The elephant remains, so abundant even in the highest 

 pleistocene bed, are commonly treated as those of the animals of that 

 period. These remains occur in the neighbourhood of the Wealden 

 island, and indeed everywhere, under two very different conditions. 



1 . In the beds of ancient lakes, ponds, or river-beds, where, as at 

 Petteridge, Peasemarsh, Valley of Arun, &c., great quantities of bones 

 and entire skeletons occur. 



2. In the sands and gravels of the drift : in these beds the remains 

 consist of the harder portions only, and are mostly water- worn. 



A recent examination of the Crag deposits of Suffolk, in company 

 with Mr. Prestwich, Mr. Morris and Mr. Tyler, has satisfied me 

 that the change from pliocene to pleistocene conditions took place 

 by gradual subsidence, and consequent decrease of the area of dry 

 land of England which was contiguous to the pliocene sea ; that this 

 was attended by a diminishing temperature ; and that the marine 

 conditions, so far as animal life was concerned, had assumed their 

 arctic character long before the whole of Northern Europe had 

 reached its greatest amount of depression. The remains of the land 

 animals have, in the case of the drift beds, been derived from the 

 sweeping of the surface of the area of dry land over which the plei- 

 stocene waters spread, and over which surface such remains might 

 have been accumulating for countless ages. These, and the remains 

 in the bone-caves, represent the fauna of the whole period during 

 which the principal part of this island was in the condition of dry 

 land. 



The period at which we have clear evidence of the area of 

 the Channel having been occupied by sea, is separated from the 

 eocene formations by such a long lapse of geological time, that a 

 glance at its condition during the interval forms a necessary part of 

 its physical history. I endeavoured to show, in a former paper on 

 part of South Devon f, that along every valley through which a river 



* Exhibited when the paper was read, but not included in the illustrations. 

 t Geological Transactions, vol. v. 



