118 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 5, 



On the south side of the Splugen I could find no terrace whatever ; 

 but all round the Lake of Como there are the remains of a terrace 

 of coarse gravel, some 200 or 300 feet above the lake ; and therefore 

 betvj^een 900 and 1000 feet above the sea. 



In descending from the S. Gotthard to Bellinzona, the highest 

 terrace observed was at Giornico, 1 234 feet ; but in Val Blegno 

 there is a terrace a little above Olivone at 3100 feet, and another at 

 Agoa Rossa at about 2100 feet ; and in the branch valley of 

 Misocco there are several terraces above Misocco, between 2500 and 

 3500 feet in elevation. Near Bellinzona there are several large 

 alluvial flats at 30 feet, 100 feet, 160 feet, 190 feet, and 230 feet 

 above the Lago Maggiore, which may perhaps be due to a gradual 

 lowering of the waters of the lake, and not belong to the class 

 of terraces under consideration ; but between Locarno and Bellin- 

 zona there is a well-marked terrace at 981 feet elevation, — that 

 is, 300 feet above the lake. 



In Val Onsernone, which ends at the Lago Maggiore, there is 

 a large terrace at Intragna at 1 300 feet, another some 300 or 400 

 feet higher, and another about 300 feet below Intragna ; of the 

 last two I have not the exact altitudes, but the last probably corre- 

 sponds to the terrace observed between Locarno and Bellinzona 

 at 981 feet. 



In Val Isone, which drains into the Lake of Lugano, the highest 

 terrace observed was at an elevation of above 2000 feet ; but, having 

 no known height near it as a point of comparison, I could not fix its 

 altitude accurately. 



Round the Lake of Lugano there is a well-marked terrace a few 

 hundred feet above the lake, of which I did not measure the eleva- 

 tion ; here we may doubt whether to attribute this to a lowering 

 of the water of the lake or to a more general cause. 



For more convenient comparison I have thrown these observations 

 together in a tabular form, see Table, No. II. p. 123. 



General Results from the foregoing Observations on Terraces, — 

 The first point to which I wish to call attention is that there are ter- 

 races at the same elevation in valleys which have no connexion with 

 one another ; thus, in valleys opening both on the Rhine and the 

 Rhone there are terraces between 4770 and 4780 feet, between 4340 

 and 4350 feet, and between 3815 and 3825 feet. Both in the 

 Valtelline and in the valley of Entremont, which falls into the Rhone, 

 there are terraces at 3770 feet. In the Valtelline and the valleys 

 connected vsdth the Rhine there are terraces at between 3110 and 

 3120 feet, between 2930 and 2940 feet, and between 2330 and 2350 

 feet. 



I think these are conclusive proofs that the terraces were formed 

 by the sea which surrounded the Alps at these periods and entered 

 into all the valleys : for it is incredible that there should have 

 been so close an agreement of level in a number of independent 

 lakes, such as would be formed by closing the valleys of the Rhine, 

 the Rhone, and the Adda by glaciers or any other barriers. 



The numerous correspondences of level in terraces which occur in 



