Changes in the Area of the Irish Sea. 59 



to an extent of at least 1600 feet. At one period during the 

 re-elevation (which was to an extent of about 15 feet above 

 the present high-water-mark), there was a stationary interval, 

 the sea-bed of the time of the formation of the great drift- 

 gravel being left dry, and forming an extensive plain stretch- 

 ing out and uniting the present countries of England, Scot- 

 land, Ireland, and Wales. 



I believe that at the same time England was similarly united 

 to the Continent of Europe. 



Then succeeded the second Elephantine period in which 

 took place the immigration into these regions (amongst other 

 quadrupeds now herein extinct), of the Cervus Megaceros or 

 Great Irish Elk, whose remains have been found in the Isle of 

 Man embedded in fresh water marls occupying basin-shaped 

 depressions in the great drift-gravel plain. 



The presence of these remains indicates the existence of 

 large treeless districts during a considerable time in which 

 the race greatly multiplied. Into the changes of climate 

 and surface of the country which led to its ultimate extinc- 

 tion I will not now inquire. The basins containing the marls 

 in which the remains are found, and the plains themselves, have 

 since been covered with vegetation, and are still in many parts 

 occupied by beds of turf, in which are found the trunks of 

 trees, chiefly oak and elm. 



But during the same period the ocean appears to have been 

 quietly eating back its way into this terrace of the drift gravel, 

 and resuming its more ancient sway, separating again Ireland 

 and the Isle of Man from Great Britain, and cutting off the 

 further immigration of animals and plants. Along all our 

 coasts we find cliffs of this drift-gravel retiring in many 

 places to a little distance inland, but where the gravel rests 

 upon palaeozoic rocks forming often part of the present coast- 

 line. 



It would be fruitless to speculate upon the length of 

 that stationary period during which the process of the dis- 

 truction of this upheaved sea-bed was going on. To excavate 

 Castletown bay, in the south of the Isle of Man, alone must 

 have occupied many hundred years. How many thousands 

 must have been taken up in cutting out, by the same process 



