84 J. S. GAEDIfEE ON" THE LOWER EOCEiJfE PLA:jrT-BEDS 



occur among the columnar series. J^ow there is only one flora, whose 

 age is stratigraphically ascertained, that the Irish plants resemble; 

 and this is the Heersian flora of Gelinden, so low down in the Eocene 

 that we have no representatives of it in England. The resemblance 

 is not superficial, but, as I intend to demonstrate on another occa- 

 sion, fundamental. Already in the Mull beds, and equally in our 

 oldest English Eocene floras from below the London Clay, the Heersian 

 characteristics have disappeared. On the other hand, these Irish 

 floras have not one single element in common with any of ascertained 

 Miocene age. In this communication these must remain merely bald 

 statements requiring corroboration ; but I intend, as I have said, to 

 go so fully into the matter at a future time, that it would be useless 

 to do so imperfectly row. 



I will now proceed to describe the actual localities whence the 

 plants are obtained, so that the conditions under which thej' have 

 been preserved may be realized. The Ballypalady locality has been 

 described to this Societj^, and I therefore content myself with a 

 reference to it almost confined to points previously overlooked or 

 where my interpretation differs. The Glenarm mine has only been 

 described at second-hand and from recollection, owing to its having 

 been inaccessible for many years, and no account of it has been laid 

 before this Society. The BaUantoy beds have only yielded an insig- 

 nificant number of plants, and are therefore not of very great interest. 

 The Lough- jSTeagh beds, on the contrary, are of such vast extent and 

 thickness and so little is known regarding them, that I have thought 

 it well to collect all the actual observations I can find on record 

 likely to assist in determining their age. Hull and Kinahan unite 

 to consider them Pliocene ; but it will be seen that some of the older 

 writers agree with members of the Belfast Eield Club, especially 

 Messrs. Gray and Swanston, in considering their age to be contem- 

 poraneous with the basalt ; and this view I do not hesitate to uphold. 

 Einally I have thought it useful to add, for comparison, some notes 

 taken during a two days' visit to Ardtun Head in Mull. 



Before going further, I cannot help calling attention to the re- 

 markable support the physiography of this district lends to a theory 

 I have sometimes advocated, namely, that the addition of weight at 

 any given spot causes a depression of the earth's crust in some degree 

 equal to this addition. The basalt forms a high plateau on every 

 side except towards Lough l^eagh. Here there is an area of at least 

 40 square miles of accumulated sediment which has been bored to a 

 depth of 300 feet without bottom, and here only are the basalts 

 dragged down, as it were, to beneath the sea-level. I have further 

 shown that the theory, pushed to one of its logical conclusions, de- 

 mands a slight uptilting of coast-lines and that cliffs should have an 

 inland dip. A glance at the arrows on the Geological- Survey map 

 shows that the dips are invariably in accordance with this theory, 

 falling away from the sea with every point of the compass demanded 

 by the shore^con tours, producing anticlinals on the opposite sides of 

 sea-loughs. Again, though the lofty shore dips inland as usual 

 opposite Eathlin Isle, the strata are exactly reproduced there on a 



