EUROPE DURIXG THE GLACIAL PERIOD. 459 



The Alpine glaciers were much more extensive, filling the 

 whole valley between them and the Jura Mountains, and push- 

 ing up upon them to their summits. Eastward they deployed 

 in the valley of the Rhine as far as Strassburg, and westward 

 into the valley of the Rhone as far as Lyons, while southward 

 they extended nearly to Turin and Verona in the valley of the 

 Po. The accompanying map of Professor Penck shows their 

 full extension eastward into Austria and the three successive 

 epochs which he names the Wiirm, the Riss, and the Mindel, 

 after the three rivers in which the several deposits were most 

 typically preserved. These correspond to the Wisconsin, 

 the Illinoisan and the Kansan episodes in America, and were 

 readily recognized as such by Mr. Leverett. For its bearing 

 on later theorizing, it is worthy of notice that these several 

 borders are closely parallel to each other and not separated 

 by any great distance. 



