440 Dr. Nils Olof Hoist — The Ice Age in England. 



duration and comes immediately before the Mousterian stage, which, is 

 in the main the equivalent of a later geological stage, namely, the 

 maximum of glaciation. At Menchecourt the ' raised beach ' layer 

 rests, as just said, on Chellean, and must therefore belong either to 

 a later stage of Chellean or to the Acheulean. Lastly, as regards the 

 erratics in the 'beach', they certainly bear witness to floating spring 

 ice or perhaps also to floating icebergs (most probably the inland ice 

 had already invaded Scotland), that is to say, they bear witness to 

 advancing cold, but in no way, as some have tried to maintain, to 

 retreating cold. All these observations concerning the age of the 

 ' raised beach ' are therefore not contradictory to one another and can 

 be brought into complete agreement. 



We now proceed to a somewhat more detailed account of the 

 deposits of the glacial depression, which are undeniably of much 

 interest. They consist of shell-bearing marine sand, gravel, which 

 on the geological map sometimes is called 'valley gravel', partly 

 rounded in the usual way, partly but little rolled and ' angular ' 

 ('coombe rock,' 'rubble drift,' 'head'), the two kinds of gravel 

 being sometimes mixed, as well as loam, which has no fossils except 

 for the very rare land shells that have been washed down into it. 



These deposits are found along the whole south coast of England 

 wherever the shores were not too steep to prevent their deposition, 

 and have also been proved on the French coast at Sangatte. They are 

 particularly well developed in the district round Chichester, Sussex. 

 The formerly depressed region is here spread out as a remarkably fine 

 and level sea-platform, the northern limit of which proceeds right 

 across the map of the district in an almost straight east and west 

 direction and immediately strikes one as an evident shore-line. In 

 Goodwood Park the marine limit appears to ascend to a height of 

 157 feet above O.D. The marine fauna, so far as it is as yet 

 known from the fine section at the last-named locality, is a North Sea 

 fauna "like that now living on the south coast of England", with 

 Cardium edule, Mytilus edulis, Tellina lalthica, Trophon sp., as well as 

 a newly found lamellibranch from the bottom layer of the locality, 

 'tabular concretions,' a small example kindly determined for me as 

 a species of Modiola by Mr. B. B. Newton of the British Museum. 

 " At first sight," says Brest wich, 1 " these sands appear unfossiliferous, 

 but a short search shows the presence of a number of minute and very 

 friable shells from \ to -§- inch long, and which proved to be the 

 young, apparently, of the common mussel. I also found a few 

 full-grown specimens of this shell and of the common edible cockle ; 

 but they all fell to pieces when touched." This I believe to depend 

 on the fact that the water here on the south coast of England, which 

 had become more and more cold during the glacial depression, now at 

 last during the Goodwood Bark stage became altogether too cold and 

 also altogether too fresh to permit of the molluscan fauna which lived 

 in it attaining its full development. 



As regards the gravel, God win- Austen has remarked that it occurs, 



1 J. Prestwich, 1859. " On the Westward Extension of the old Kaised 

 Beach of Brighton, etc." : Quart. Journ. Geol. Soc, vol. 15, pp. 215-21, see 

 p. 219. 



