THE FORMATION OF GLACIERS. 
211 
titles in the drift about the neighborhood of Paris, 
and quite recently they have been traced even to 
the foot of the Pyrenees, where their presence 
would, of course, indicate a climate similar to 
the one now prevailing in Northern Scandinavia. 
Side by side with the remains of the Reindeer 
are found those of the European Marmot, whose 
present home is in the mountains, about six thou- 
sand feet above the level of the sea. The occur- 
rence of these animals in the superficial deposits 
of the plains of Central Europe, one of which is 
now confined to the high North, and the other 
to mountain-heights, certainly indicates an entire 
change of climatic conditions since the time of 
their existence. European Shells now confined 
to the Northern Ocean are found as fossils in 
Italy, — showing that, while the present Arctic 
climate prevailed in the Temperate Zone, that of 
the Temperate Zone extended much farther south 
to the regions we now call sub-tropical. In Amer- 
ica there is abundant evidence of the same kind ; 
throughout the recent marine deposits of the 
Temperate Zone, covering the low lands above 
tide-water on this continent, are found fossil 
Shells whose present home is on the shores of 
Greenland. It is not only in the Northern hem- 
isphere that these remains occur, but in Afiica 
and in South America, wherever there lias been 
an opportunity for investigation, the drift is found 
