1)6 



SCAXDIXAVIA. 



î^ortli Sea with the Baltic, as clearly shown by tracts now covered with marine 

 fossils. Oysters have been picked up on the south shore of Millar, a sure proof 

 that these waters had formerly at least 17 parts in 1,000 of salt. Bjorko, one of 

 its islands, was till recently strewn with the bones of sea- fowl as well preserved as 

 if they had been just forsaken by the mews after breeding season, ^iiy, more, there 

 still survive small animals of marine origin whose organism has been slowly 

 adapted to the fresh water gradually replacing the sea in the lacustrine basins. 

 Even the Norwegian Lake Mjosen, notwithstanding its distance from the strait of 

 which Wetter and Wener are detached links, still harbours the Mt/sis relicta, 



Fig. 48. — Lake Malak. 

 Scale 1 : 695,000. 



20 Miles. 



a living species bearing witness to its former connection with the neighbouring 

 seas, whose temperature was at that time as low as is now the Frozen Ocean. 



Henceforth severed from the sea by slowly widening isthmuses, the great 

 lacustrine basins dividing Sweden into two distinct regions have continued to rise 

 with the rest of the land. Their surface is now above sea-level, although the beds 

 of most of them are below the surface of the Baltic, "Wener, the largest of the 

 Scandinavian lakes, with an area one-tenth the size of all the rest together,* has a 

 mean elevation of over 141 feet, with an extreme depth of 290 feet. It is thus 

 two or three times larger than Lake Geneva, and about one-fourth the size of 

 Ladoga. Wetter, at twice the altitude of Wener, is also deeper, measuring 

 413 feet, and 125 below the level of the surrounding seas. Hjelmar, lying nearer 

 * Area in square miles : —Wener, 2,386; Wetter, 733; Malar, 668. 



