112 GEOLOGICAL FEATURES. \AliyUst. 



This is matter of grave consideration. When, or did 

 the sea ever invade these heights? Yet the cartilagi- 

 nous hinge was perfect, and the epidermis in many in- 

 stances scarcely removed. Birds may have placed these 

 shells ; but with our knowledge of this climate, prevail- 

 ing ice, and the scarcity of animal life especially, this 

 is scarcely credible. I cannot, will not, at present say 

 more. This friable sandstone and sand, interspersed on 

 the surface with boulders of granite, and almost garnet 

 masses, constitutes the principal features of the land on 

 the west of North Cornwall. 



