FAUNA OF THE LOW LEVEL GRAVELS. 



305 



the lower level gravels are more numerous than those from 

 the upper levels. 



Mr. Prestwich gives the following table of the mammalia : 



To this list we must add the lemming, the Myodes torquatus, 

 and the musk ox, which has been found at two spots in the 

 Thames valley, as well as at Chauny on the Oise. 



The mollusca are fifty-two in number, of which forty- two 

 now live in Sweden, thirty-seven in Finland, and thirty-eight 

 in Lombardy. Bearing in mind that Lombardy is much 

 richer than Finland in mollusca, this assemblage has rather 

 a northern aspect. 



There are, however, three species which seem to point 

 southwards. It may be fairly objected that the Hippopotamus 

 major, bones of which occur in the drift, could scarcely have 

 existed in a cold country. Mr. Prestwich, indeed, suggests 

 that this species may, perhaps, like its gigantic relatives, 



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