THE MIOCENE. 



593 



Fig. 682. A.ioplotherium commune : paheotherium magnum and minus ; 

 and crocodile. 



that by sinking of the area the estuary had become longer, wider, and 

 deeper, but still remained connected with a vast continent, through which 

 the Eocene river flowed." 



The Miocene deposits 

 are not so generally impor- 

 tant in the United Kingdom, 

 but in America very valuable 

 fossils have been discovered 

 in these strata. The Pliocene 

 strata extend along the east 

 of Great Britain, where they 

 are denominated " Crag," as 

 Norfolk Crag, Red Crag, 

 Coralline Crag. Underneath 

 these mammalian remains 

 have been discovered. After 

 the Pliocene we come to the 

 Post-Pliocene, which really 

 closes the long Tertiary period. During these ages the gradual development 

 of created beings apparently reached its height. It was towards the end of the 

 Middle Eocene that the great mountain chain of Europe came into existence, 

 which is connected, as any casual observer may see, with the Himalaya. In 

 fact, the whole chain, from the Thibetian range through India, the Caucasus, 

 Alps, and Pyrenees, is continuous, and formed of the same material (" num- 

 mulitic limestone "). There is no doubt that the whole northern hemisphere 

 enjoyed at the commencement of the Tertiary period a warm, not to say 

 tropical, climate, which got colder and colder. 



\Vc find the increase of animals and plants more fitted to the require- 

 ments of man and our present climate. There are many signs of the 

 successive increase of land in Europe generally, while the contrast the 

 Tertiary period bears to the Secondary is -very marked. In the former we 

 have extensive deposits in the waters of wide, open seas ; in the latter the 

 depositions were evidently made where dry land, with its accompanying 



bays and lakes, were extensive and 

 numerous. The former is marine, 

 the latter lacustrine and marine 

 The seas of the Tertiary period have . 

 lately been defined. 



Sir Charles Lyell, in his 

 " Principles of Geology," shows us , 

 this, and defines the European fea- 

 tures at the commencement of the 

 Tertiary epoch. At that time, the 



British islands, with the exception of the basins of London, the Isle of 

 Wight, and Norfolk, had wholly emerged from the deep. But a third 



38 



