GEOLOGICAL NOTES ON THE ISLE OF PORTLAND. 65 



seen at the present time. In his summary Professor Prestwich 

 says : Carrying our view back to the latter part of the Glacial 

 period, before the present valley system, or even some of the 

 plains were elaborated, a broad tract of Chalk, bounded in places 

 by Greensand and capped by Tertiary beds and other gravels ran 

 inland, and with them the Purbeck and Portland beds were brought 

 into level juxtaposition by and along the great line of fault run- 

 ning east and west, nearly midway between. 



The presence of Elephas antiquus in the Portland 

 mammaliferous drift brings us back to a period long anterior to 

 the Neolithic age, which did not commence immediately at the 

 close of the Palaeolithic ; but a great gap intervened between 

 them. We find Palaeolithic man feeding upon the reindeer 

 which pastured upon the reindeer moss, the Alpine birch and 

 willow of Central France during the cold of the second Ice age. 

 Neolithic man did not appear until after the Mammoth had dis- 

 appeared, and the cave lion and hysena no longer wandered in 

 our forests, and not until the Germanic flora had succeeded the 

 Arctic, which was driven from the lowlands of Europe to the 

 mountainous districts. I must leave this interesting subject and 

 the consideration of the High and Low Land Valley Drifts to 

 some future occasion when next we meet here or in the neigh- 

 bourhood. 



