ON THE ORIGIN OF COAL. 151 



geologists, and sanctioned by the remains of 

 the Cheirotherium, some insects, the Stonesfield 

 slate, and other animals, is very probable ; but 

 positive evidences in support of it, have not to 

 my knowledge been hitherto adduced. At the 

 present time the whole of the dry land upon the 

 face of the globe could be covered by the waters, 

 and a universal sea of considerable depth exist. 

 Great mountain ranges, such as the Himmylaya 

 and the Andes, could easily be buried in the 

 depths of oceans like the Pacific and Atlantic. 

 This is mentioned for the purpose of shewing 

 that it is not necessary to assume the existence 

 of perfectly dry land, in order to account for such 

 seas as those in which most of the beings whose 

 remains we find embedded in the older rocks lived. 



The lowest slates of North "Wales seem to indi- 

 cate a sea of considerable depth, the sedimentary 

 deposits at the bottom of which were often dis- 

 turbed by admixture of volcanic matter in the 

 shape of trappean rocks. It is a diflScult matter 

 to state when the first evidence of animal life 

 appeared in the waters of the ancient sea, but 

 there is proof that it existed near Arenig Fawr, 

 where the Asaphus Buchii and a few other fossils 



