178 PICTURESQUE SKETCHES 



and, for the purpose of crushing the shells of such 

 creatures, these fishes were provided with a pavement 

 of hard rough enamelled teeth fixed on the palate. 

 The whole body also and the head were covered 

 with plates of bone, also coated with enamel, and 

 serving as a defence against the attack of the 

 larger ammonites and belemnites. Farther out at 

 sea were tribes of sharks of different species, all pre- 

 daceous and carnivorous, and many of them of the 

 most gigantic proportions. No fishes like those now 

 common on the coasts of England then existed on the 

 earth. 



The fishes, though abundant and represented by a 

 powerful and important group, had ceased to be the 

 lords of creation in the lias seas. The depths of the 

 sea as well as the shallows, the broad expanse of 

 waters as well as the coast-line, were in those days 

 the dwelling-places of a group of reptiles of which 

 every representative has long since become extinct. 



Two of these have more especially attracted atten- 

 tion, in consequence of their great abundance in the 

 fossil state in our own country, but they are by no 

 means the only ones known. Of these two, one was 

 more exclusively tenant of the deep, while the other 

 was probably more frequently met with on the mud 

 banks or on shore. Both were truly marine in their 

 habits, and both seem to have served as the represen- 

 tatives of the great cetacean tribe the whales, the 

 porpoises, and other similar animals now existing. 



It is difficult to imagine, without appearing to cari- 

 cature, the conditions of existence of such animals. 

 We know indeed their form, their proportions, their 

 strange contrivances of structure, their very skin, and 



