152 
THE OEOLOGIST. 
THE Lower Ludlow Eocks. — Dear Sir, — I sec I have been called to 
account, in n\orc than one ])agcof your February number, for errors of omission 
and coiinnission ; and in acknowledgin!^ the paternal rebuke, I am bound to be- 
comea contributor pro Imifo this month. 
First then, with regard to Major Austin's communication, which, in its latter 
and more important ])art, gives iis a fact of very high interest, viz., the occur- 
rence of man in a true raised beach ! 
I believe his notice of the small patch of fossiliferous strata on the Water- 
ford coast is quite correct, and that the strata of Newtown Head, opposite his 
old station at Duncamion, are really of Llandcilo age. But the statement in 
" Siluria" is also true, viz., that all or n(>arly all* the Silurians of the south- 
cast portion of Ireland are referable to the Caradoc rocks. It is a wonderfully 
covered-u]) country : those who have not ridden across the drift-surfaces whicn 
clothe these denuded Silurian tracts can have little idea of the difiiculty of 
getting continuous sections. Hence it is impossible to say with accuracy that 
we may not find anything or everything Siliu'ian there. But after the best 
attention that could be given to the whole tract, the government surveyors 
cannot determine any true ecpiivalents of either the lowest or the succeeding 
Silurian beds. Prof. Jukes has shown that there are no Lingiila flags deter- 
minable, and I must be responsible for saying that over the greater portion, at 
least, of this wide district of Wexford and Waterford there is no proof of any- 
thing that can be called Llandeilo-rock, nnless it be in the locality under con- 
sideration. It is remarkable it should be thus. The Silurian strata are highly 
contorted, cleaved, and interstratified with abundance of igneous rocks ; as 
much so in parts as the Llandeilo-flag range of Cader Idris, or the wild country 
round the vale of Ffestiniog. But the Irish traps interstratilied with fossil- 
bearing slates are cliiefly of the age of those of Snowdon, and these belong to 
the overlying series — the Caradoc or Bala rocks, as was shown clearly by Prof. 
Ramsay in his published sections. Now it so happens that one of the New- 
town Heads in Waterford (that near Framore) is an excellent example of the 
Caradoc strata, and is rather a cons])icuous locality for fossils, many of which 
were published in General Portlock's work. The other New1;ow^l Head, from 
which Mr. Aust in gathered his rare organisms (sent to General, then Lieutenant- 
colonel Portlock) is immediately op])osite Duneannon, but on the Waterford 
side of the esttiary. It is rather a matter of satisfaction to me to tind that 
tne sets of fossils are from distinct localities, for ccrtaiidy the large species of 
trilobite, O.ri/fjia Portlocki and the others Ampi/u-^ and Acidaaim, found by 
Major Austin in his own locality are good Llandcilo types, at least they are 
such as we may find in other Llandedo-flag districts, such as Builth, in llad- 
norshire. But though Caradoc is clearly superposed upon Llandedo-flags, the 
diiferencc between the faunas of the two foi-mations is not so great or decided 
as to enable anyone at a glance to separate them ; and there are other districts 
even in Ireland where perhaps the sauie distinctions may hereafter be drawn, 
but of which our knowledge is not perfect enough to enable us to do so at 
present. All the typical Lower Silurian districts of Ireland, let me say mean- 
while, are of the Caradoc or Bala type, not even of Ijlandeilo age. I allude to 
the Portrane district near DubUn, the Tyrone, and probably the Fermanagh 
tracts, and, as before said, by far the greater part of Wexford, if not of Wick- 
low. In Galway we have middle Silurian rocks ; in the picturesque Dingle 
promontory, the Wenlock and Ludlow beds ; and what may be revealed when 
* The strata near Waterford are specially excepted as probably of LlandcUo |agc (p. 185, 
2nd edit.). I do not Iciiovv on what data. 
t Culipneiie dnplU-aia is mentioned bj' Mr. Austin; I have only seen C. hrevicapitata from 
the soulli of Ireland. 
