214 GLACIAL HISTORY. 



was still in the vicinity. Whilst this deposit belongs to the 

 period of the retreat of the glacier, the loess of the lower part of 

 the Rhine valley probably originated at an earlier period, when 

 it had a greater extension. Of the numerous snails which have 

 been collected in it, the species of shady moist localities certainly 

 predominate ; and with them are mixed several forms (such as 

 Helix hispida, Miill., H. ruderata, and H. arbustorum subalpina), 

 which at present are met with only in high mountains, whilst no 

 species occur which belong to warm sunny localities. 



The Mollusca of the drift agree with those now living 

 in Switzerland; but the Mammalia present six peculiar ex- 

 tinct types. Seventeen species of mammals have at present 

 been discovered in Switzerland. Three of these have been 

 already noticed in the lignite formation, namely : the cave-bear, 

 the teeth of which have been found in the Wildkirchli cavern, 

 under a bed of calcareous tufa ; the red deer, which is widely 

 spread in the Quaternary formation ; and the urus (Bos primi- 

 genius), remains of which have been collected in the drift - 

 formation of the Isteinerklotz. Besides the urus, a second spe- 

 cies, the aurochs (Bos bison prisons), has been found in Swit- 

 zerland. Its great horn-cores and a portion of the skull were 

 found in a railway-cutting at Bollingen, near Rapperschwyl. 

 Hence the two wild oxen mentioned by Seneca and Pliny were 

 in existence in the period of the drift -formation. The aurochs 

 or bison is a large fierce animal, with a long mane like the 

 American buffalo. Both the urus and the aurochs are found in 

 the Swiss pile-dwellings ; and even in the middle ages the aurochs 

 was widely spread in the European forests, but is now preserved 

 only in the great forest of Bialowicza. The giant stag (or Irish 

 elk, Cervus eurycerus, Aid.), of which remains have been found 

 at the Isteinerklotz, was an animal of nearly equal size. Of the 

 elk (Cervus alces, Linn.) an entire skeleton was brought to 

 light in the Val Tr avers. 



In the Wildkirchli the bones of the foot of a chamois (Antilope 

 rupicapra, Linn'.) were found in the same place as the teeth of 

 the cave-bear, so that this animal was already in existence in the 

 Quaternary period. This is confirmed by remains found in the 

 valley of the Rhine, which demonstrate that at that time the 

 chamois, as well as the ibex and the marmot, inhabited the low 



