1872,] TIDDEMAJS" ICE-SHEET IN NORTH LANCASHIRE ETC. 471 



Mr. CARRirTHERS said that as the rhizome, whether it was that of 

 Aspidium or Osmunda, was an aerial, and not a subterraneous rhi- 

 zome, it must have been carried to its present position ; and it con- 

 sequently indicated, as Col. Lane Fox had pointed out, the direction 

 of the stream. 



Mr. Floavek regarded Col. Lane Fox's memoir as of great interest, 

 as affording an additional instance of that perfect similarity of these 

 deposits, whether in France or England, which in places so wide 

 apart might reasonably be taken to indicate a common origin. It 

 was indeed generally assumed that these deposits were brought 

 down by rivers ; but this, according to his view, was by no means 

 certain. Col. Lane Fox had described the valley as 4| miles wide ; 

 but there was at Croydon, 12 miles distant, a deposit of gravel 

 capped with loess, containing elephant-remains, and exactly resem- 

 bling the Thames-valley gravels, and communicating with them. 

 This evidently formed part of the Thames-valley system, whatever 

 that system might be taken to be ; and if so, he thought it incre- 

 dible that the loess should have been distributed by river-action over 

 an area 12 or 15 miles in width. In conclusion, he was quite 

 content to adhere to the opinion held by the French geologists, 

 and formerly by several of our own most able writers, that the dis- 

 tribution of these superficial drifts was in the first instance diluvial 

 rather than fluvial. 



Col. A. Lane Fox, in reply, pointed out the artificial character of 

 the implements, and the manner in which the mammahan remains 

 occurred. He thought that some part of the brick-earth of the 

 lower terraces might have been deposited at the bottom of a lake. 



Mr. Busk, in proof of the animal-remains not having been brought 

 from a distance, showed that remains of the same animal were 

 found in close proximity to each other. 



Prof. Eamsay made some remarks on the undoubtedly artificial 

 character of the implements, and on their position at the base of the 

 gravels. The origin of the Thames valley he had already main- 

 tained to be of Postmiocene age ; and though there was at present 

 no evidence of man's existence at that time, it was still possible. 

 Of the extreme antiquity of the human race there could, however, 

 be no doubt. 



4. On the Evidence fot^ the Ice-sb;eet in North Lancashire and 

 adjacent parts of Yorkshire and Westmoreland. By R. H. 

 TiDDEMAN, Esq., M.A. Oxon., F.G.S., of the Geological Survey of 

 England and Wales. 



[Communicated by permission of the Director General of the Greological Sm;Teys 

 of the United Kingdom.] 



[Plate XXX.] 



Introduction. 



The materials on which the remarks are founded which I now have 

 the honour of submitting to the Society, have been collected by me 



