I 



[ 479 ] 



XXYII. 



OIN" THE ORIGIN OF THE lEISH LA.ND AND FRESHWATER 

 FAUNA. By R. F. SCHARFF, Ph.D., B.Sc. 



[Read ISTovembek 12, 1894.] 



In a report on the " History of the Irish Fossil Mammals,"^ submitted 

 to the Royal Irish Academy, the late Professor Leith Adams made a 

 few remarks with regard to those past geographical conditions of 

 Ireland, which permitted mammals such as the Irish elk, reindeer, 

 wolf, and mammoth to migrate to this country. He says in this 

 report : " The probability is, that the migration came from Scotland, 

 and that there was a land communication between the two countries 

 at the close of the Glacial Period, by which the greater portion of the 

 mammals that had found their way to Scotland crossed to Ireland." 

 He was led to this belief by the fact that all the living and extinct 

 mammals of Ireland, with the exception of the grizzly bear, have 

 been recorded also from Scotland, whilst a large number of the English 

 extinct mammals, such as the lion, spotted hyena, glutton, cave bear, 

 and many others, are absent both from Ireland and Scotland. 



The method indicated by Professor Leith Adams, by which the 

 fact of the presence of both recent and extinct mammals of an island 

 can be utilized in a research into its past physical geography, has led 

 me to devote some time to a detailed consideration of the origin of 

 some of the more important groups of Irish vertebrates and inverte- 

 brates. 



I have paid particular attention, in the first place, to the mammals. 

 The existence in Ireland of such large mammals as the mammoth, 

 Irish elk, grizzly bear, and others, proves almost beyond a doubt that 

 they must have found their way to this country by a land communi- 

 cation which united it with Great Britain. From a study of the 

 extinct mammals of England, it is possible to arrive at some satis- 

 factory conclusion as to the particular geological period during which 

 this land connection existed, and also as to when Ireland became 

 separated from Great Britain. Another point of great interest presents 



^ Adams, A. Leith, " Eeport on the History of Irish Fossil Mammals," Froc 

 Roy. Irish Acad., vol. iii. (ii. ser.), 1883. 



