v.] PREHISTORIC ARCHEOLOGY. 143 



Elephas primigenius (the mammoth), E. antiquus, 

 Rhinoceros tichorhinus (the hairy rhinoceros), R. lepto- 

 rhinus, R. liemitcechus, Hippopotamus major (the hippo- 

 potamus), Ovibos moschatus (the musk ox), Megaceros 

 hibernicus (the Irish elk), E. fossilis (the wild horse), 

 Gulo luscus (the glutton), Cervus tarandus (the reindeer), 

 Bison EuropcBiis (the aurochs), Bos primigenius (the 

 urus) ; besides some smaller, but still very interesting 

 species. 



4. The greater severity of the climate is indicated 

 by the nature of the fauna. The musk-ox, the woolly- 

 haired rhinoceros, the mammoth, the lemming, &c., are 

 Arctic species, and the reindeer then extended to the 

 South of France. Another argument is derived from 

 the presence of great sandstone blocks in the gravels of 

 some rivers, as, for instance, of the Somme : these, it 

 appears, must have been transported by ice. 1 On the 

 other hand, the geological evidence, together with the 

 presence of the hippopotamus, and other southern species, 

 indicates that the cold was not continuous, but that warm 

 periods intervened. 



5. The great antiquity of the period now under 

 discussion is evident from several considerations. The 

 extinction of the large mammalia must have been a 

 work of time ; and neither in the earliest writings, nor 

 in the vaguest traditions, do we find any indication of 

 their presence in Western Europe. Still more conclusive 

 evidence is afforded by the condition of our valleys. 

 The beds of gravel and loam cannot- have been deposited 



1 Since this lecture was written two excellent works have been 

 published on this part of the subject Geikie's Great Ice Age, and 

 Croll's Climate and Time. 



