XXXI.—DINGLE AND GLENGARIFF GRITS, sy G. H. 
KINAHAN, ».n.1.4., &c. Puate 14. 
[Read 21st April, 1879. ] 
From the comments that have been made on my representation 
of the relation between the Dingle Beds and the Glengariff Grits, 
with the accompanying diagrammatic section in Chap. IV. of my 
book on the Geology of Ireland, it would appear that some further 
explanation of the subject is necessary, and this I now propose 
to give. 
But first I would refer to the recently published paper on “ The 
Old Red Sandstone of Western Europe,” by Dr. A. Geikie (rans. 
Roy. Soc., Edin., vol. xaviit., p. 345), as his statements in reference 
to the “Old Red Sandstone ” of Scotland have particular bearing 
upon the present question. In p. 347 of that paper he states :— 
1.) “My own work in the centre and south of Scotland had proved 
the Old Red Sandstone to consist of two great divisions—a lower pass- 
ing down conformably into the Upper Silurian shales, and an upper 
graduating upwards into the Lower Carboniferous.” 
And at page 353 he affirms, when contrasting the uniformity of 
the stratified rocks of Silurian age with the Old Red Sandstone :— 
(2.) “No such general uniformity of stratification presents itself in 
the Old Red Sandstone. On the contrary, with the accumulation of the 
deposits in limited basins, come local and often peculiar features, whereby 
even contiguous tracts are distinguished from each other. It is still 
possible roughly to make out with more or less clearness the limits of 
the basins, &ec.” 
These remarks, as I have shown in a former paper, are very 
applicable to the corresponding Irish rocks ; as everywhere, ex- 
cept in 8.W. Ireland, the Irish rocks, similar to those called by 
Dr. Geikie “Upper” and “Lower Old Red Sandstone,” are dis- 
cordant with each other; while everywhere the Upper graduates 
into the Carboniferous, and in different places the Lowe into the 
Silurians. Wealso find great lithological differences in the rocks 
of the different areas or basins. Geikie at page 354 divides the 
rocks classed by him as the “Lower Old Red Sandstone” of Britain 
into five great “ Basins of Deposit.” Of these, No. 4 he calls the 
