29 20 Proceedings of the Royal Irish Academy. 



to which I referred in a previous paper (" The Aquatic Coleoptera of the 

 Mid-Ebudes," loc. tit.). The entire absence of Forbes' " Lusitanians " from 

 Britain might also perhaps be regarded as favouring the view of their pre- 

 Glacial existence in Ireland. 



The fact that the ice-sheet at the climax of the Glacial period did not 

 completely cover the whole British area no doubt helps to make the question 

 of survival of the fauna and flora more difficult. The north and south 

 migration ceased perhaps before all the temperate species had been ex- 

 terminated but it seems difficult to believe that much of our present fauna 

 and flora could have endured the " tundra " conditions which appear to have 

 existed even in the South of England. 



If, as seems possible, at least the bulk of the southern species came from 

 the south then, on the grounds already stated, they are post-Glacial 

 immigrants. If, on the other hand, the climatic conditions were not so severe 

 as many believe and the bulk of the fauna and flora survived in the country, 

 then they arrived from the north and possibly only the warm temperate 

 species localised in the south and east have arrived since the passing away of 

 the Glacial period. 



Bibliography. 



1898. Halbert, J. N. : " Impressions of Achill," Irish Nat., vii, p. 135. 

 (Mentions two species — H. obscurus and 0. bicolon.) 



1898. Irish Field Club Union, Kenmare Conference- 

 Irish Nat. vii, p. 212. (Mentions capture of P. nigro-aeneus in 

 flood refuse, Erriff Paver in spring, 1897.) 



1901. Johnson, W. F., and J. N. Halbert: "A List of the Beetles of 

 Ireland." Proc. Eoy. Irish Acad., Ser. iii, vol. vi. (Mentions seven 

 species from Mayo, but only in the case of H. tristis and H. 

 obscurus is any reference to locality given. These are both West 

 Mayo records.) 



