io6 The Irish Nat7tralist. 



nite beds of the clays, associated with iroiivStone nodules 

 containing a rich assemblage of plant-remains, which point to 

 a Middle or Lower Eocene age for the containing deposits. 

 As all the fossil evidence obtained from the plant-bearing beds 

 intercalated with the basalts of Antrim also points to the same 

 horizon, some of the fossils being common to both, we cannot 

 escape the conclusion that the basalts are of the same age, 

 which is one much earlier than that previously assigned them ; 

 and they thus rank with the famous deposits of Mull and 

 Greenland, and form perhaps part of the remains of the same 

 stupendous volcanic outbursts. During the intervals in these 

 outbursts, dense vegetation flourished, lakes and mountain 

 tarns received deposits of detritus and vegetable matter 

 from highlands, the pOvSition of which we cannot now even 

 conjecture. Succeeding lava-outbursts overwhelmed most 

 of these lakes, and their sediments were by heat and pressure 

 converted into what are now the plant-bearing iron ores of 

 Antrim. The lignite beds of Lough Neagh, lying just 

 outside the south-western fringe of these immense lava 

 sheets, escaped the fate which overwhelmed the more northern 

 deposits, and thus they still retain their unaltered plastic 

 character. Infiltration of silicious waters, such as often accom- 

 pany volcanic activity, reached some of the buried wood, 

 altering its woody structure and forming the silicified wood 

 of Lough Neagh. Students of geology in this age of enquiry 

 would probably never have known of the existence of this in- 

 teresting fossil, had not the ice of a Glacial Epoch cut deeply 

 into the deposits, scattering their contents far and wide to 

 delight and puzzle them. 



NOTES ON THE FLORA OF THE ARAN ISLANDS. 



BY NATHANIEIv COI^GAN. 



\ Concluded frojii page 78). 



Thk third day's work in Aranmore was the most successful 

 of all. Traversing the island from Kilronan to Bungowla, in 

 the extreme west, and returning by the .shore through Port 

 Cowruck and Monastir, I noted the range of the Aran 

 form vincalc of Hclia7ithenmm cannvi, found three additional 



