THE FORMER EXTENSION OF GLACIERS. 
153 
Crystalline mountains of the Simplon and St. Bernard, 
where it is very abundant.* 
The animal kingdom also affords us similar evi- 
dence. We find living colonies of Alpine and Arctic 
animals, especially Insects and Molluscs, on the sum- 
mits of isolated mountains and in the marshes be- 
hind moraines, in association with Alpine plants and 
erratic blocks. Moreover, just as land animals have 
retired up the mountains, so have aquatic species 
been driven into deeper and colder waters — Nephrops 
norvegicus, for instance, into the depths of the sea 
at Quarnero, several Arctic animals into the deep 
waters of the Swedish lakes Wenern and Wettern. 
In the glacial deposits remains of various Arctic 
species have been met with. In the gravel-beds 
near Maidenhead, Charles Kingsley and I found a 
skull of the Musk Sheep, and remains of the same 
species, though rare, have since been met with in 
other parts of Europe. With the Musk Sheep, the 
Urus, the Aurochs, the Wild Horse, the Mammoth, 
Hairy Rhinoceros, Reindeer, Elk, the Giant Stag or 
Irish Elk, Glutton, Ibex, Chamois, Cave Hyaena, Cave 
Bear, Polar Fox, Lemming, Ptarmigan, Marmot, 
Snowy Owl, etc., have been also found in glacial 
Heer, Primaeval World of Switzerland, vol. II. 
