INTERGLACIAL EPOCHS. 



3°3 



has recorded remains of the mammoth and the urus (Bos primi- 

 genius), and some land-shells. 1 



A bed of lignite, similar to that of Utznach and Diirnten, 

 is found at Chambery and Sonnaz in Savoy. It is interstratified 

 with beds of clay and gravel, which repose upon an unknown 

 depth of fine sand, and are covered by 100 feet of glacial 

 deposits. From the character of the vegetable and insect 

 remains in the lignite and clay, and from the geological position 

 of the deposits, they are believed to be of the same age as the 

 interglacial lignites of Switzerland. 



The climate of the interglacial epoch, during which those 

 lignites were accumulated, appears to have been not unlike that 

 of the same regions at the present day, and the antiquity of the 

 deposits is shown by the presence of the extinct forms of plant- 

 and animal-life. 



In certain of the Alpine valleys of Northern Italy we again 

 encounter lignites associated with old glacial deposits, which 

 present some very interesting features. The most important, 

 from our present point of view, are those which occur at Leffe, 

 in the basin-shaped valley of Gandino that opens upon the 

 Yal Seriana, and the similar but less well-developed lignites of 

 the Val Borlezza, whose stream discharges into Lake Iseo. The 

 deposits have been admirably described by Professor Stopanni, 

 whose observations I have to a certain extent corroborated by a 

 personal examination of the ground. 2 



The Lago d'Iseo, as is well known, has formerly been filled 

 by a great glacier that descended from the higher Alps by the 

 Valle Camonica, and advanced for some distance into the plains 

 of Lombardy, where its terminal moraines now form the crescent- 

 shaped line of hills known as the Colline della Francia Corta 

 [See Plate B]. s When the glacier reached its greatest develop- 

 ment it sent off a branch which left the main trunk near the foot 



1 Urwelt der Schweiz, p. 532. 



2 Corso di Geologia, vol. ii. p. 657 et seq. j Geologia d' Italia, per A. Stopanni 

 et G. Negri, Parte II., p. 243 et seq. 



3 Plate B is taken from Stopanni's Corso di Geologia. 



