BAILY ON FOSSIL PLANTS FROM THE SOUTH OF IRELAND. PART II. 47 



After which was read a paper 



On Fossil Plants from the South of Ireland (Part II.). By William 

 Hellier Baily, P. L. S., P. G. S. 



Having at the last meeting of the Society finished with the considera- 

 tion of those found in the Old Red Sandstone, I propose to bring before 

 the notice of the Society on this occasion an account of fossil Plants pro- 

 cured from rocks belonging to the Carboniferous formation. 



The rocks known as the Carboniferous slate (a term applied to them 

 by Sir Richard Griffith), and believed to be the lower portion of the 

 Carboniferous formation, are extensively developed in the South of Ire- 

 land, skirting the shores of Kenmare and Bantry, as well as Dunmanus 

 and Roaring "Water Bays, and extending across the country in a north- 

 east and south-westerly direction to Cork Harbour and Ballycotton Bay. 

 The series of beds composing these rocks consists, according to the Geo- 

 logical Surveyors, of a mass of dark blue and grey slates, with occa- 

 sional thin beds of grit, interstratified at the lower part with thicker 

 beds of grit — these grits having been named by Mr. J. Beete Jukes, 

 Director of the Geological Survey of Ireland, Coomhola grits, from the 

 name of the place, near Glengariffe, where they are best seen. The esti- 

 mated maximum thickness of the Carboniferous slate in the county of 

 Cork being 5000 feet, this series of strata, resting conformably upon 

 other grits and slates referred to the Old Red Sandstone, and graduating 

 so imperceptibly the one into the other, that the boundary could only 

 be determined by observing the change of colour from grey slates and 

 grits into that of a red. and liver-coloured hue, fossil Plants of a similar 

 character being common to both, the only certain guide as to their rela- 

 tions with the Carboniferous formation resting with the fossils, marine 

 shells of characteristic Carboniferous species, which have never been 

 found lower than what are called the Coomhola grits, or the grey and 

 black slates, with which they are interstratified. 



The vegetable remains occurring throughout these beds consist al- 

 most entirely of fragments of stems and branching Plants without leaf- 

 lets, a condition which renders them difficult to determine. Although 

 Plant remains are found at some places in considerable abundance, the 

 varieties of forms are but few, there being only two or three well-recog- 

 nised species met with throughout the whole extent of these deposits, 

 the most conspicuous of them are large stems, the majority of which 

 appear to be identical with Sagenaria Veltheimiana (Sternberg, sp.), 

 and smaller Plants, with diverging branches, named by me Fill- 

 cites lineatus. Plants of similar character, as I have before observed, 

 also occur in beds referred to the upper Old Red Sandstone, correspond- 

 ing in that respect with the lithological blending of the two formations 

 into each other, and rendering the boundary between them a somewhat 

 arbitrary one. The Rev. Professor Haughton,* after describing the 



* " On the Evidence afforded by Fossil Plants as to the boundary line between the 

 Devonian and Carboniferous Rocks." — "Journal of the Geological Society of Dublin," 

 vol. vi., p. 227, &c. 



