RETROSPECT. 407 



cycadeae, and ferns, flourished up to a late period 

 of the Cretaceous epoch.* 



IV. The Tertiary Epoch. — The bed of the 

 chalk ocean was broken up, and considerable areas 

 were elevated above the sea, and covered with 

 vegetation, and tenanted by pachydermata and 

 other mammalia ; the dry land of Europe during 

 this period was less extensive than at the pre- 

 sent time. 



In the basins and depressions formed by the 

 submerged portions of the cretaceous strata, new 

 sediments began to take place ; the sea which 

 deposited them teeming with marine animals, dis- 

 tinct from those of the pre-existing ocean. Local 

 intrusions of freshwater deposits, abounding in 

 the spoils of the land and its inhabitants, denote 

 the existence of islands or continents, tenanted 

 by mammalia allied to the tapir, elephant, rhino- 

 ceros, horse, deer, &c. ;-f and the vegetable remains, 

 consisting of palms and dicotyledonous trees, indi- 

 cate an approach to the flora of the warm regions of 

 the south of Europe. A few reptiles, principally 

 of the alligator and crocodilian types, and lizards of 

 small size, appear as the representatives of the 



* Evidence : The Jguanodon, and freshwater turtles, pine-trees and cycadeae 

 of the greensand of Maidstone ; the ferns of the greensand of the Isle of 

 Wight, p. 230; the Clathraria Lyellii of the chalk-marl at Bonchurch, p. 244. 



t Evidence : see p. 117, and p. 169. 



