VI PREFACE. 



This work was written as the outcome of a paper 

 published in the Proceedings of the Royal Irish 

 Academy (3rd series, vol. iv., 1897), "On the Origin 

 of the European Fauna." A summary of that paper 

 appeared in Nature (vol. Ivi., 1897), and fuller extracts 

 of more important parts, with some criticisms, in the 

 Geological Magazine (N.S., sec. iv., vol. iv., 1897). I 

 freely acknowledge the value of these criticisms, 

 which have largely assisted me to amplify and to 

 improve upon the ideas laid down in the paper. 



I have found that it greatly facilitates comprehension 

 of the arguments used, to give a few maps indicating 

 in a general way the extent of former seas and 

 continents. I may in this way, as Mr. Kendall 

 has pointed out, have submerged many square 

 miles of land which had never been covered by the 

 sea, at least not within recent geological times, 

 but the maps were intended as illustrations of my 

 views in a broad spirit only. 



Some zoologists may be surprised that, in some 

 cases, I have not followed the latest views in revised 

 nomenclature. I felt that in a work of this kind 

 it was of supreme importance to employ names still 

 current in our leading text-books, such as Lepus 

 variabilis for the Mountain Hare, instead of Lefius 

 timidus. After each chapter I have endeavoured to 

 give a short summary of contents, while a biblio- 

 graphy of the principal works and papers consulted 

 will be found at the end. I should also acknowledge 

 the aid which I have received from such excellent 



