FOURTH CRETACEOUS PERIOD. 



No remains of terrestrial animals of this period have been found, 

 and the only traces of vegetation are the remains of wood "on the 

 borders of the basins, with a few plants found at Lyme Regis 

 and elsewhere. 



429. Discordances in the strata indicate the convulsion which 

 closed this period. 



rOUETn CRETACEOUS PERIOD. 



430. The fourth stage of the Cretaceous formation, called by 

 M. D'Orbigny the Cenomanian, corresponds very nearly with the 

 twelfth group, or upper green sand-stone of Lyell, including the 

 Merstham fire-stone and the marly-stone, with chert of the Isle of 

 Wight. 



431. The generic forms of the fauna were as follow : 



Synopsis of the Animal Kingdom (exclusive of Annulata] during the 

 Fourth Cretaceous Period. 



Among these a new genus of reptiles called the Haphiosaurus, 

 and one of fishes called Otodus, were included. 



432. The shores of the seas of this period underwent some 

 changes, owing probably to a subsidence of the ground. They 

 advanced in Belgium as far as Tournay. They covered also 

 that extensive surface included between Fecamp and Tours, and 

 between Tours and Bourges, submerging ground which had re- 

 mained dry land since the close of the Jurassic age. They 

 covered also the whole extent of the Pyrenean basin, from the 

 department of the Loire Inferieure to that of the Lot, and from 



109 



