APPEARANCE OF VERTEBRATE ANIMALS. 133 



clearer waters, and the more varied continental profiles of the 

 later geological periods. Thus physical improvement and the 

 changes of animal and vegetable life are linked together by 

 correlations which imply not only design, but prescience, 

 whether we attribute these qualities to a spiritual Creator or 

 to mere atoms and forces. 



Fig. 121.— Cretaceous Fishes of the modern or T ileoslian type. 



Beryx Lewesiensis. English chalk, b, Poriheus molossus (Cope). A large fish 

 trom the American Cretaceous. One twenty-eighth natural size. 



The history of fishes extends further through geological time 

 than that of any other Vertebrates, and is perhaps more com- 

 pletely known to us, in consequence of the greater facilities for 

 the preservation of their remains in aqueous deposits. If 

 we receive Pander's Conodonts as indicating a low type of 



