238 
SCENERY OF SWITZERLAND. 
2. Corrie lakes. 
3. Those due to moraines. 
4. Those due to rockfalls, landslips, river cones,' 
glaciers, or lava currents damming up the course of 
a river. 
5. Loop lakes. 
6. Those due to subterranean removal of soluble 
rock, such as salt, or gypsum. These principally 
occur in Triassic areas. 
7. Crater lakes. 
8. The great lakes. 
1. As regards the first class, we find here and 
there on the earth’s surface districts sprinkled with 
innumerable shallow lakes of all sizes, down to mere 
pools. Such, for instance, occur in the district of 
Le Pays de Dornbes between the Rhone and the 
Saone, that of La Sologne near Orleans, in parts of 
North America, in Finland, and elsewhere. Such 
lakes are, as a rule, quite shallow. They are due to 
the fact of these regions having been covered by 
sheets of ice which strewed the land with irregular 
masses of clay, gravel, and sand, on a stratum im- 
pervious to water, either of hard rock such as granite 
or gneiss, or of clay, so that the rain cannot percolate 
