Sir H. Soicorth — Recent Changes of Level. 407 



temperature is attested by the so-called glacial shells found on the 

 north-eastern coast of England, and the eastern coast of Scotland, 

 from the warmer waters of what is now the English Channel, whose 

 temperature is similarly attested by the shells found at Selsea. 



S. V. Wood, jun., speaking of the Selsea beds, says " they contain 

 a marine fauna quite unlike that of any post-Glacial marine beds in 

 England and Scotland, and consisting of species, all of which are 

 living. Nearly all the shells live on the south coast, but a few do not 

 now reach us, but have their northern limit on the Lusitanian coast ; 

 so that the English Channel at some post-Glacial time (? post- 

 Glacial, H. H. H.) was subjected to an influx of Lusitanian water, 

 which afterwards ceased when the Lusitanian shells disappeared." 



The disappearance of the Lusitanian shells can be explained, most 

 rationally as it seems to me, by the breakdown of the isthmus in 

 question, which would allow the cold waters of the North Sea to 

 circulate into the Channel, and thus lower the temperature of its 

 waters. 



Li the collapse of this land-bridge we have some evidence of the 

 considerable subsidence which took place at the close of the 

 Mammoth age. If we travel westward it is almost certain that 

 the separation of the Isle of Wight from the mainland took place at 

 the same time, for the remains of the Mammoth and its companions 

 have been found there as on the mainland. 



Further west the evidence is more definite. Eound the coasts of 

 Dorsetshire, Devonshire, Cornwall, and Somerset, there have been 

 found large remains of submerged forests, and both in Torbay and 

 Bideford Bay, on the two sides of the great western English pro- 

 montory, there have occurred Mammoth's teeth, apparently derived 

 from these beds. These clearly point to a considerable submergence 

 of land in the west country after the Mammoth time, and, as the 

 teeth and bones ai'e unweathered, it would seem to follow that it 

 was immediately after the destruction of the Mammoth that the sub- 

 mergence took place. A similar conclusion was arrived at by Dr. 

 Falconer and the explorers of the Gower Caves, who concluded that 

 it was impossible for herds of great herbivorous animals to live in 

 a district like that in which the Gower Caves are situated, unless 

 its condition was very different, and that the facts point to the 

 submergence of a considerable extent of champagne country at 

 the close of the Mammoth era in the district now occupied by the 

 Bristol Channel. 



If we now turn to the Irish Sea we shall have reason to come to 

 the same conclusion. In the middle of the Irish Sea is the Isle of 

 Man. In the Isle of Man have occurred remains of the great Irish 

 Deer in the marls underlying the peat bogs. Similar remains have 

 occurred in Great Britain, and of course in Ireland, and they mean 

 that a land-bridge must have existed connecting the three areas. 

 That this land-bridge existed in the Mammoth age we cannot 

 positively say, since no Mammoth remains have hitherto occurred, 

 I believe, in the Isle of Man, and there is some doubt as to whether 

 the Irish Deer did not survive the Mammoth period in Ireland. But 



