472 Mr. Weaver on the Structure of the South of Ireland^ 
tive transition series, and to all, or some, of such beds as the 
case may be, when thus coloured, affixing also the term “ old 
red sandstone e. g., in Macgillicuddy’s Reeks, in Dunloe 
Gap, in Purple, Tomies, and Glenaa mountains, in Brickeen 
island and Muckruss peninsula, and in the valley of Ken- 
mare. Yet Mr. Griffith himself, in combating the positions 
of Mr. Charles W. Hamilton, insists that the red sandstone, 
where occurring in these localities, has been deposited con- 
formahly on the older slate (which latter he seems disposed to 
refer to the Cambrian or Silurian aeras), and in a descending 
order graduates imperceptibly into that rock*. This being 
admitted, v/hy not designate this a transition red sandstone 
(as I have always done) in contradistinction to the old red 
sandstone of the carboniferous epoch, found in unconformable 
position, and commonly distinguished, in some parts of its 
extent at least, by beds of red clay, red marly clay, and red 
slaty clay ; e. g., in the Slieve Meesh range and in Kerry 
Head? Much ambiguity would be avoided by observing this 
difference in language. Again, after such an admission, it 
may be asked, why are these rocks, together with the lime- 
stone of Muckruss, of the islands of the Lower Lake of Kil- 
larney, and extending toward that town, blended by Mr. 
Griffith with the carboniferous series? This limestone within 
its own area not only alternates with certain beds of the 
older stratified rocks, the prevailing dip being to the south, 
but in their lateral extension it is enveloped by and interlocked 
with them, which latter relation is clearly proved by the posi- 
tion cf the greywacke, sandstone, and slaty-rocks in the north- 
western portion of Muckruss peninsula, intervening between 
the limestone of the islands on the north and that of the 
south-eastern portion of the peninsula. Mr. Griffith con- 
ceives he has solved the question by the introduction of a 
faidt ranging from Dunloe Gap through Purple, Tomies, 
Glenaa, and the southern part of Brickeen Island, and under 
Turk Lake to the main land east, where it is confessedly not 
visible, diluvial matter occupying the surface. This supposed 
fault does not appear to rest on any proof of actual disrup- 
tion by an up or down thrown or by a lateral movement^ but to 
be merely an inference drawn from the difference of strike 
observable between the strata that have been interrupted in 
their eastern and western continuation by the excavation of 
Dunloe Gap or by the formation of Turk Lake or the Lower 
Lake. I have seen no such dislocation in the masses extend- 
ing from Dunloe Gap through Purple, Tomies and Glenaa 
* L. & E. Phil. Mag. March, p. 162, 166. 
