FOSSILS OF TERTIARY EPOCH. 73 



of the secondary epoch. It extends over a large 

 district of the interior of England, and reaches to 

 various parts of the coasts of Hampshire, Sussex, 

 Kent, Norfolk and Yorkshire. It consists chiefly 

 of marine strata, comprehending the white lime- 

 stone called chalk, and various marls, clays, and 

 sandstones. 



This formation abounds with the remains of 

 extinct species of zoophytes, molluscs, fishes and 

 reptiles: the characters of the chalk formation 

 are those of a vast oceanic basin, filled up with 

 organic and inorganic debris, the innumerable re- 

 mains of successive generations of marine animals 

 which lived and died in its waters during periods 

 of incalculable duration. 



Having thus briefly reviewed the several forma- 

 tions which belong to the secondary epoch from 

 the most ancient and lowest formation to the 

 least ancient and highest, in the series, we are 

 now to consider the fossils of that epoch which 

 intervenes between the secondary and the modern 

 or human epoch. 



The TERTIARY EPOCH comprises an extensive 

 series of marine, fluvio-marine and lacustrine 

 deposits, containing the remains of all the existing 

 orders of animals and vegetables associated with 

 those of numerous extinct genera. This formation 

 extends from the interior along the northern coasts 

 of Kent to those of Norfolk, Lincolnshire, and 

 part of Yorkshire, H ampshire and Lancashire. 

 At the time of the great chalk or cretaceous for- 

 mation, which, as we have seen, is the last and 



