THE PEAT. 375 



To this list we may 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. 



Let us now visit some of the pits at the lower levels. At 

 about thirty feet lower, as for instance at Menchecourt, near 

 Abbeville, and at St. Eoch, near Amiens, where the gravel 

 slopes from a height of sixty feet down to the bottom of the 

 valley, we find almost a repetition of the same succession; 

 coarse sub-angular gravel below, finer materials above. So 

 similar, indeed, are these beds to those already described, that 

 it will be unnecessary for me to give any special description 

 of them. 



It is possible that when the fauna and flora of the upper 

 and lower-level gravels shall have been more thoroughly inves- 

 tigated, they may be found to be almost identical. At present, 

 however, the species obtained from the lower-level gravels are 

 more numerous than those from the upper levels. 



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 Lornbardy is much 

 richer than Finland in mollusca, this assemblage has rather a 

 northern aspect. 



In such a group of species as this, the hippopotamus seems 

 singularly out of place, and in the preceding chapter I have 

 discussed the conclusions which are, I think, to be drawn 

 from its presence : taking the fauna as a whole, however, and 

 looking more especially to such animals as the musk ox, the 

 reindeer, the lemming, the Myodes torquatus, the Siberian 

 mammoth, and its faithful companion the woolly-haired rhi- 

 noceros, we have clear evidence of a climate unlike that now 

 prevailing in Western Europe. 



Finally, the lowest portion of the valley is at present occu- 

 pied by a bed of gravel, covered by silt and peat, which latter 

 is in some places more than thirty or even forty feet thick, 



