88 



BRITISH EOCENE FLORA. 



identical, but associated with the scale of a similar cone ; and it may therefore possibly 

 have had a considerable range in Europe. The foliage and cones are easily distinguish- 

 able from any others in the British Tertiaries. 



The variety recently obtained from Glenarm approaches far more closely to the 

 ordinary and more luxuriant type at present existing in Japan.^ 



The iron-ore or bauxite mine of Libbert, vi^hence they were obtained, is situated at 

 about 700 feet above the sea-level and nearly a mile in rear of Glenarm. No outcrop of 

 the strata is visible in its vicinity, except an occasional patch of basalt on the roadside ; 

 but its position must be some 400 or 500 feet above the junction with the Chalk, and 

 therefore probably at about the same horizon as the plant-bed at Ballypalady. The shaft 

 or adit is horizontal, and the work of draining it, though long and laborious, was not 

 one of serious difficulty. For the first 20 or 30 feet it pierces Boulder-clay, and about 

 a dozen feet farther in, a compact, almost white, sandy clay is reached, in which the plant 

 remains occur. The base of the adit is almost indurated micaceous sand of unknown 

 thickness, said by the miners to repose on lithomarge. As the beds rise slightly with 

 the slope of the hill, the rest of their thickness can be studied as they are successively 

 cut through. The " leaf-bed " is more compact and clayey, and for about a foot in thick- 

 ness contains well-preserved plant impressions. It passes upward into imperfectly 

 laminated clayey sand, stained grey with vegetable matter, and enclosing limbs and trunks 

 of trees. The "leaf-bed " seems to be confined to an area of not more than two square 

 yards, but the darker clayey sand extends far into the mine, and contains less distinct 

 impressions at those points where it has been examined. Overlying this is a singular 

 conglomerate made up of rounded pebbles of reddish indurated clay embedded in a hard 

 gritty paste. The surfaces of these pebbles are polished and darkened by squeezing and 

 pressure, and it is difficult to realise at first that some of them are not flints. There are 

 also coarse quartz grits cemented together by a clayey matrix. The bauxite, a ferru- 

 ginous hydrate of alumina, overlies these, and is said to be about 30 feet above the 

 " leaf-bed," and also contains masses of lignite and trunks of trees. Deeper in the mine 

 it becomes blotched with red and gradually passes into the iron-ore, by which it also is 

 overlain. The deposit, like those of Ballypalady and Ardtun Head, is fluviatile, and 

 marks the former bed of a river. 



The leaf-bed, though rich in specimens is poor in species. There are but two pre- 

 vailing varieties of leafy trees, the commonest being a large and deeply indented leaf, 

 such as might be borne by a large-leaved oak or maple ; and the other a long parallel- 



1 When the descriptions of the Coniferse were first undertaken, none of the materials for the plates 

 illustrating the Basaltic Flora of Ireland had been brought to light. The method of publication in yearly 

 parts permits revision and addition while the work is in progress, and the latest interval has been utilised 

 in repeated visits to Antrim, during which the Ballypalady specimens, occupying plates xv — xx, were 

 obtained and figured. A further slight delay has also enabled me to insert an account of the fine speci- 

 mens just obtained from Glenarm. The plant-beds had been deep under water at the time of my former 

 visits. 



