ON DINGLE BEDS. AND GLENGARIFF GRITS AND SLATES. 699 
54. On the GrotoctcaL AcE of the Rocks forming the SouTHERN 
Hieutanps of Iretanp, generally known as “Toe Dine e 
Beps” and “ Gurnearirr Grits and States” (Jukes). By 
Professor Epwarp Hutt, LL.D., F.R.S., F.G.8., Director of the 
Geological Survey of Ireland. (Read April 9, 1879.) 
CoNTENTS. 
I. Introduction.—Views of previous authors. Charles W. Hamilton, Thomas 
Weaver, Sir R. Griffith, Rev. Prof. Haughton, Professor J. B. Jukes, 
and J. W. Salter, G. V. Du Noyer, John Kelly, Sir R. I. Murchison, 
The Geological Survey of Ireland. 
II. Reexamination of Sections. Dingle Promontory—suceession of beds. Evi- 
dence from fossils. Parkmore-Point conglomerate. Killarney, Ken- 
mare, Sneem, and Glengariff districts. Supposed conformity of the 
Glengariff series and the Carboniferous beds not proven. 
III. Comparison with Sections in Galway and Mayo. Upper Silurian Rocks of 
West Galway and Mayo. ‘Table of representative beds. Volcanic rocks. 
Plant-remains. 
IV. Relations of the Upper Silurian series of the South-west of Ireland to those 
of the Silurian region of England. Table of supposed representative 
beds. Conclusions from above. 
V. Relations of the Old Red Sandstone to the ‘ Dingle beds §c.” Lower and 
Upper Old. Red Sandstone of the South of Ireland. Suggested relations 
to the Devonian rocks, 
VI. General conclusions. 
I. Iyrropvction. 
THE geological age of the formations which rise into the highest 
elevation in the South of Ireland, and form the central masses of the 
promontories which jut out far into the Atlantic in the counties of 
Kerry and Cork, has been long a subject of controversy. They have 
been referred by successive authors to the Silurian, Devonian, and 
Old Red Sandstone periods. While I would refrain from speaking 
dogmatically on a question which may be incapable of absolute 
demonstration, | wish to place before the Society the reasons which 
have induced me to agree with those who have referred these beds 
to the Upper Silurian age. Before proceeding to the discussion of 
those points which seem to me to bear directly upon the question at 
issue, I will briefly notice the views expressed by previous authors 
on the subject. 
Views of Previous Authors.* 
1838. In this year Mr. Charles W. Hamilton, in a paper entitled 
“ An Outline of the Geology of part of the County of Kerry” +, de- 
scribed the coast sections of the Dingle promontory, noticing the 
beds with Silurian fossils and the overlying slates and grits, and 
* A fuller account of these views than that here presented was drawn up by 
the author, but by order of the Council it has.been curtailed. 
+ Journ. Geol. Soc. Dubl. yol. i. (1858). 
