TRANSACTIONS OF THE SECTIONS. 75 
Old Red of this locality, while the section through the Beacons of Brecon shows 3000 
feet for the beds above the Cornstones, and those near Llandeilo at least 5000 feet for 
the vertical beds of the Cornstone group, without reckoning the upper gently inclined 
beds near the escarpment of the carboniferous limestone. The tortuous boundary of 
the Upper Silurian and Old Red in the valley east of Pontypool forbids the supposition 
of its being a fault. 
As a general result, the author stated his belief that it was possible the Old Red 
Sandstone (so called) of South Wales might be really two things, just as the New Red 
Sandstone of former days is now believed to be two things, although it is probable that 
from their similarity of character their separation may ke more difficult in the Old than 
. it has been in the New, and may perhaps be found to be impossible. 
Mr. J. B. Juxes exhibited and described the one-inch Geological Map of Ireland, 
as far as published. 
On the Geology of Lambay Island. By Messrs. Jukes and Du Noyrer. 
On the Valentia Trap-District. By G. H. Kinauan. 
These traps occur in the Glengariff grit formation, and seem to have been con- 
temporaneous with the aqueous beds. On the mainland, and on part of Begenish, 
they are conformable; and on the rest of Begenish, and on the Island of Valentia, 
they are unconformable. The lowest place in the formation where they are observed 
is to the south of Beenakeyraka, where they make their appearance as a dyke. It is 
then lost under the bog and drift, but is seen again when we go east, at the north of 
Glanleam, the seat of the Knight of Kerry. On Begenish, and the mainland, we 
meet with six different volcanic periods. ‘The first is greenish-white compact felstone, 
which seems to be very local, as it is only met with at one place. Second: green- 
stone ash, which seems to have been very general, as it is found everywhere but 
on the mainland. Third: felstone, either blue, black, or greenish. It is generally 
_ separated from the last by a bed of altered slate, and has always, except on the main- 
land, a bed of altered slate on the top of it. This bed of felstone is found every- 
where when we get a section. Fourth: the great igneous action of the period, which 
is a greenstone more or less felspathic. The centre of action would seem to have 
been at the east of Begenish, as here, where the fault is marked, there is an uncon- 
formability. It would seem also to have been near this place that the vent of the 
previous irruptions had taken place, as they are all represented here. ‘he dyke in 
_ Valentia would seem to be the feeder that supplied this greenstone. It runs under 
the Quarry Hill, not making its appearance from Beenakeyraka until you come to the 
north of Glanleam, where it is lost in the sea opposite the Begenish traps. This bed 
is also found on the mainland, and can be traced inland for about a mile. In places 
it is in regular columns, and everywhere has a tendency to be columnar. Tifthly: 
compact felstone of a dark blue or purplish colour, It is found lying on the top of 
the greenstone, but dies out as we go east. To the north it is slightly hornblendic, 
but everywhere else it is a compact felstone. Sixthly: trappean breccia, which lies 
on the top of the last. It is made up of pieces of all the foregoing traps, along with 
slates and grits, imbedded in a green matrix. At Laght Point, and at the south-cast 
of Begenish, there is a slight inversion. 
On the Zoological Relations of the Cambrian Rocks of Bray Head and 
Howth. By Professor J. R. Kinauan, M.D., M.RLA. 
These rocks can be no longer loeked on as azoic, as in these two localities they will 
be found full of traces of organic life of three types at least. 1st. Zoophytic: Old- 
hamia, of two species, which occurs in immense beds in Bray, Co. Wicklow, and 
sparingly at Howth, Co. Dublin, where it was first discovered by the author in 
1857. 2nd. Annelidan: tracks of wandering worms, Arenicolites, arranged in the 
same direction as the bedding found both at Howth and Bray. Worm burrows, ver- 
tical to the bedding, and arranged in pairs similar to those in the Longmynd, 
Worm-tubes of a new type, for which the name of Histioderma Hibernicum was sugs: 
