AND THEIR DESCENDANTS 



was probably an archipelago, ranging over ten degrees of 

 latitude, like many of the island groups now found in the 

 great Pacific Ocean ; the old gneissic hills of the western 

 coast of Scotland, culminating in the granite range of Ben 

 Nevis, and stretching to the Southern Grampians, forming 

 the nucleus of one island group ; the South Highlands of 

 Scotland, ranging from the Lammermuir Hills, another ; 

 the Pennine chain and the Malvern Hills, the third and 

 most easterly group ; the Shropshire and Welsh moun- 

 tains, a fourth ; and Devon and Cornwall stretching far to 

 the south and west. Every spot of the island lying now 

 at a lower elevation than 800 feet above the sea was 

 under water at the close of the Silurian period, except in 

 those instances where depression by subsidence has since 

 occurred. 



211 



