478 Proceedings of the Royal Irish Academy. 



islands, such as Bear Island, King Charles' Land, and others, which 

 must be looked upon as the remains of a much larger mass of land. 

 The sea has broken thi'ough and diminished tliis land considerably in 

 the course of time, as is very evident in the case of Bear Island. 



In referring to a number of shallow- water mollusca, common to 

 the coast of Greenland and Finmark, the late Prof. Forbes said 

 (335, p. 36) : " that these littoral mollusks indicate, by their presence 

 on both sides of the Atlantic, some ancient continuity or contiguity of 

 coast-line, is what I firmly believe. The line of migration of most of 

 these shell-fish was most probably from west to east, from America 

 to Europe, during a different state of physical conditions from those 

 which now prevail on our side of the ocean." It was probable, there- 

 fore, that a current existed in the Arctic Ocean, from west to east, 

 and this offers an explanation for the very remarkable and sudden 

 appearance of no fewer than eighteen American species of mollusca in 

 the newer crags of the east coast of England. In the last chapter, 

 p. 461, I explained how the German Ocean was connected with the 

 White Sea across Northern Russia, at a period which certainly ante- 

 dated that of the Forest-bed ; and that was, no doubt, the way in 

 which these mollusca above referred to, which had been brought to 

 the White Sea by the westerly current, reached the east coast of 

 Britain. Had they come straight across the Atlantic from America, 

 we should find some traces of them in such beds as those of St. Erth, 

 in Cornwall, which is probably of about the same age as the newer 

 crags. But Messrs. Kendall and Bell (49), who have studied these 

 deposits carefully, do not report the occurrence of auy of these 

 American forms, while, from the absence of Arctic species, they are 

 led to think that the Arctic Ocean did not then open into the Atlantic. 

 They suppose that a land-communication must have existed between 

 Europe and America, so as to form a barrier of separation between the 

 Ai'ctic and Atlantic Oceans. 



I think it has been clearly shown that a former land-connexion 

 must have existed between Scandinavia and Greenland on the one 

 hand, and between Scandinavia and the British Islands on the other, 

 and that it formed the highway for an extensive migration from the 

 north, and vice versa. Most naturalists, indeed, admit this, but many 

 deny that it could have been anything but post-Glacial. I believe 

 that the migration took place chiefly in later Pliocene times, i.e. 

 during the deposition of the newer crags and of the lower continental 

 boulder-clay. The Arctic animals and plants certainly reached the 

 British Islands long before the Sib(;rian immigrants. Throughout the 



