Primczval Geography, 167 



not a few of them owe their existence to the power- 

 ful action of an ocean that must once have risen high 

 against the sides of the hills, and that must have as- 

 saulted them during many ages, assisted, not improb- 

 ably, by ice. At Mottram-in-Longdendale, 568 feet 

 above the level of the sea, and 50 miles in a direct line 

 from it, is a deposit of brown, sandy clay, cut through at 

 the time of the construction of the Hollingworth reser- 

 voir of the Manchester Water-works. In this clay are 

 found not only granite and greenstone pebbles, some of 

 them angular, and others rounded, but abundance of 

 that well-known spiral shell of our Lancashire coasts, 

 called the "cockspur," Turritel'la tere'bra. Other shells 

 of similar habitat occur in the cutting referred to, the 

 deposit conclusively proving the ancient contact of the 

 waters of the ocean with those parts ; and what is quite 

 as wonderful, when we consider how vast is the length 

 of time, and the total and absolute extinction of whole 

 races and dynasties, both of plants and animals, that has 

 occurred so frequently in the history of life upon our 

 planet, what is quite as wonderful, we say, that some 

 of the inhabitants of that primaeval ocean were of the 

 same kinds as exist in it at the present moment. Long 

 must be the journeys before we shall witness and learn 

 anything more remarkable than this. Ferns, in these 

 little dingles, are especially abundant ; and at the bot- 

 tom, where the water assumes more the form of a brook, 

 with level ground upon either hand, it is curious to note 



