136 MR. E. HULL ON THE VESTIGES OF EXTINCT 



Professor Agassiz considers that there have been other 

 minor centres of glacial agency in Ireland^ as amongst the 

 Mourne mountains in Down and the mountains of Wick- 

 low. Mr. JukeSj in the case of these latter, gives an 

 instance of a boulder of granite twenty-seven feet longj 

 which had been transported seven miles, partly across a 

 wide valley.* Such a boulder, however, might have be- 

 come imbedded in a stranded iceberg from some more 

 northerly district, and have been subsequently carried to 

 its present site. At the same time, Agassiz distinctly 

 states the existence of lateral moraines in the mountain- 

 ous districts south of Dublin and near Enniskillen,t and 

 considers the Wicklow range as a centre of dispersion for 

 erratic blocks. 



North Wales. — The years 1841-42 appear to have 

 been remarkably prolific in researches into the glacial 

 phenomena of our islands, for we find Professor Agassiz, 

 Dr. Buckland, and Sir C. Lyell announcing consecutively 

 their convictions of the former existence of a state of 

 things in these islands, which have their analogues only 

 in Greenland, South Georgia, or Tierra del Fuego, at the 

 present day. M. Agassiz pointed to the Caernarvonshire 

 mountains as one of the centres of dispersion of glacial 

 and erratic detritus; and Dr. Buckland speedily followed 

 with details tending to prove that the seven valleys of 

 Snowdonia were once occupied by as many glaciers, dis- 

 charging loads of boulders and gravel over the lower 

 grounds or into the sea, and covering the bottoms and 

 sides of those valleys with flutings and furrows. He also 

 shows that on the northern flanks of this district, boulders 

 and marine drift coming from Anglesea, Cumberland, or 



* Manual of Geology, p. 551- 



f Proceedings of the Geological Society of London, vol. iii. p. 330, lu 

 the original^ tlie district is said to be situated south-east of Dublin, but is 

 evidently intended for south-west of that city. 



