DISTRIBUTE INSECT VARIETY, 



269 



plateau bodily arose and stood out from the wash of the waves, 

 making England and Ireland continuous with the Continent, and 

 presenting the English Channel and German Ocean as inland 

 plains. In the latter epoch this area was probably made drear 

 with stretches of reed and bloomy heath, with forests of oak, 

 chestnut, alder, and yew ; and at this time, according to Pro- 

 fessor Forbes, the Germanic flora travelled to Great Britain. 



MA.P OF GREAT BRITAIN IN THE MAMMOTH PERIOD. 



X X, submerged forests of the old land area, rising up at tlie coast-bne of to-day. 

 Adapted from an engraving in the Leisure Hour, July, 1874. 



Submarine channels proceeding from existing rivers and trending 

 to the then coast line have been traced by Mr. Godwin Austin, 

 and close to the ancient embouchure of one traversing the 

 English Channel, a fresh-water mollusk {Uiiis pictoruw) has 

 been obtained. Evidence of this plateau elevation may be 

 deduced from existing surface depression evinced by encroach- 

 ments of the sea, accom2:)anied with land submergences and the 

 sinking and denudation of cliffs. Mrs. Somerville relates the 

 connection of the Hebrides with Scotland; and in a MS. from 

 the Monastery of Mount St. Michel we learn that Jersey in the 



