174 Scientific Proceedings, Rojjal Dublin Sociehj. 



Ayrshire and Lanarkshire. The sequence of sandstones and shales, with thin 

 limestones, coals, and clay ironstones, intruded by a lacoolite of dolerite met 

 with in Ballycastle, is practically identical with that which we found developed 

 in the Ayrshire basin.' We have therefore to inquire whether the known flora 

 of the Ballycastle coalfield supports or denies this conclusion. Though, as has 

 been pointed out, the flora alone affords no direct evidence, I am of opinion 

 that the Ballycastle plants, in conjunction with tlie lithological characters 

 of the beds, tend to confirm the generally accepted view that these rocks are 

 the equivalents of the Carboniferous Limestone Series as developed elsewhere 

 in Britain. The three species of Lepidodendron here recorded are all frequent 

 on, though not confined to, this horizon. For instance. Dr. Kidston^ has 

 recorded L. Velthehni, Sternb., and L. Rhodeanum, Sternb., with Archceo- 

 calamites and Stigmaria from the Arigna Mines, Co. Roscommon, a very 

 similar flora to that under discussion from Ballycastle. He remarks that 

 " all these species, with the exception of Stigmaria ficoides var. rimosa, Q-old., 

 are common to both the Carboniferous Limestone series and the Calciferous 

 Sandstone series, but the position of the beds from which the fossils were 

 derived shows that the Arigna coal-field is of Yoredale age, — which is on or 

 about the horizon of the Carboniferous Limestone series of Scotland, and 

 probably about the position of the Edge Coal series of Scotland." There 

 remains, however, a difficulty as xeg&v&a Adiantites antiquus (Ett.) which has not 

 been recorded from this horizon, either in Britain or Austria. This plant, with 

 several other interesting species, was, however, determined by Dr. Kidston' 

 from the limestones of Teilia Quarry, Q-waenysgor, Flintshire, more than 

 twenty years ago. Dr. Kidston was then iuolined to " believe the Teilia beds 

 are more probably of Calciferous Sandstone than of Carboniferous Limestone 

 age." In the interval which has elapsed since this paper was written, it has 

 been shown that several plants, which were at one time regarded as confined 

 to one or other of the Lower Carboniferous horizons, are in reality common 

 to both, though often more abundant in the one zone than the other. 

 Personally, I am inclined to regard the Teilia beds as occupying a somewhat 

 high position in the Carboniferous Limestone Series. This view is based 

 partly on the stratigraphical position of the beds, but more especially on the 

 fact that a characteristic Grwaenysgor species, Sphenopteris I'eiliana, Kidst. 

 has been found to occur in the upper beds of the Carboniferous Limestone 

 Series near Chepstow.^ If this is the ease, Adiantites antiquus (Ett.) has 

 already been recorded from the Carboniferous Limestone Series of Wales, 



1 Geiltie, &e. (1872), pp. 10 aud H. ^ Kidston (1903), p. 95. 



3 Kidaton (1889), p. 421. « Arber (1907), p. 4. 



