412 Submergence. 



of the Caledonian canal, fringed by many small islands 

 on the west. The next would extend from the canal to 

 the valleys of the Tay and Forth, bordered by many 

 islands on the west and south, and in both the ground 

 was penetrated by many fiords, some of which were 

 longer than our longest fiord-lochs of the present day. 

 The third large island included most of the country 

 between the Clyde and Forth, and the Sol way and Tyne, 

 while two deeply-indented islands lay south of that line 

 and the Derbyshire hills north of Ashbourne. On the 

 east of these would lie fourteen islands, formed of part 

 of the North and East Ridings of Yorkshire, while nine- 

 tenths of Wales would form one large island with many 

 small ones lying to the east, south-east, and south, in- 

 cluding the highlands of Devon and Cornwall. 



Such islands, as far as Wales and Cumberland were 

 concerned, I am convinced still maintained their minor 

 glaciers, which descended to the sea, where their ends 

 broke off as icebergs, which, floating hither and thither, 

 deposited their stony freights as they melted. We shall, 

 however, presently see that in some districts there is 

 evidence of the country having sunk much more than 

 500 feet. 



In many parts of England shell beds associated with 

 glacial material are by no means uncommon, and it is 

 difficult to believe that in scores of places where they 

 occur, on the coast cliffs between Berwick and the 

 H umber, they had always been thrust up from the sea by 

 glaciers. The most plentiful species there, as determined 

 by Mr. Etheridge, are Cardium, edule, Cyprina Islan- 

 dica, Dentalium entalis, Leda oblonga, and Saxicava 

 ruyosa, together with undetermined species of Venus 

 and Tellina. In Cheshire, near Macclesfield, lying 

 between a lower and an upper Boulder-clay, Professor 



