Mr. Weaver on the Structure of the South of Ireland, 277 
Soc., in May, 1839*; and, 3rd, in a paper read before the 
Geological Society of Dublin, on the 13th June, 1839, the 
last-mentioned being accompanied by two sections, one re- 
ferring to the south-eastern portion of the island, and the 
other to a part of the extreme west, in the county of 
Kerryf. The view's of Mr. Griffith thus appearing in an 
authenticated form before the public, and the author having 
in his last production, while attempting to explain his own 
positions, found it necessary to assail mine, the time has fully 
arrived for adverting to those views. Being thus put on my 
defence, I shall proceed to consider, in connexion, the Outline 
with its Geological Map, and the three later written communi- 
cations, with the two sections supplied by the author ; and in so 
doing, I shall feel no difficulty in showing that many of Mr. 
Griffith’s representations are not only irreconcilable wdth the 
facts, but that those representations contradict each other :f. 
The question at issue lies more particularly between the 
older stratified rocks of the south of Ireland and the old red 
sandstone properly so called, which occurs in different por- 
tions in that quarter of the island. 
In the Outline (at p. 7), Mr. Griffith professes to distinguish 
the older stratified rocks as consisting of an older and a newer 
transition series, the latter, which is coloured purple, being 
said usually to repose unconformably on the former, which 
is coloured grey ; or, as it is later expressed in another place§, 
usually resting unconformably on the greywacke slate or Si- 
lurian series ; and the old red sandstone, which is said to 
succeed, being distinguished partly by a reddish-brown and 
* Proceedings of the Geological Society, 22nd May, ] 839. 
t Journal of the Geological Society of Dublin, vol. ii. part 1., 1839. 
J This paper was drawn up before I had seen another Geological Map 
of Ireland put forth by the author, on a large scale, in 1839’*^ and to this 
latter map, it appears, Mr. Griffith’s two last-mentioned communications 
refer also in part. If the discrepancies in the map appended to the ‘‘ Out- 
line” were startling, the numerous arbitrary alterations introduced in the 
new map are no less striking; and it may fairly be inquired what reliance 
is to be placed on either of them, disagreeing largely as they do with each 
other. I can perceive, in the new map, an approximation in some parts to 
my own views, but an utter discordance in other parts. As, however, the 
alterations which have been made in the new map do not materially inter- 
fere with the course of my argument, which in the first instance bears di- 
rectly on the map attached to the “ Outline,” I have left the text un- 
changed, merely adding incidentally a few notes in reference to the new 
map, for the purpose of continuing the comparison. The discrepancies 
between Mr. Griffith’s two maps and my own map of the south of Ireland, 
will thus become doubly apparent. 
§ Journal of Geol. Soc. of Dublin, vol. ii. p. 85. 
® Hodges and Smith, Dublin, and James Gardner, London. 
