Vol. 58.] THE FOSSILIFEROUS SILURIAN BEDS OF KERRY. 265 
in the Dingle Beds of Smerwick Harbour, and by the absence of any 
intrusions into the Old Red Sandstone. 
The quartz-porphyry, seen near Fort Dunore, intruded between 
the Smerwick Beds and the overlying Silurian, is of uncertain age, 
and so also is the labradorite-porphyrite near Ballyferriter Castle. 
(7) There is very little evidence as to the position of the vents from 
which the Silurian ashes and lavas came. The only fact which may 
possibly give a clue to the solution of this problem, is that the 
thickness of the beds formed by volcanic agency is greater in the 
southern part of the area, and hence it is possible that the vent or 
vents from which they came may have Jain to the south of the 
Dingle promontory. 
(8) The land during the deposition of the Silurian rocks could 
not have been very far off: for the Silurian sediment found here 
points to a shallow sea, or to the proximity of land. Even when 
coral-life abounded, the rock in which the corals are now preserved 
is never a pure limestone, but always of a very arenaceous character, 
though the corals are preserved not in broken fragments, but in 
layers of growth. Moreover, there are beds of conglomerate 
found in places throughout the series, which show that the volcanic 
beds in the neighbourhood were being continually denuded. They 
also point to the former presence at the surface of rocks now not 
seen in the neighbourhood, for granitic pebbles sometimes occur. 
EXPLANATION OF PLATE VI. 
Geological sketch-map of the Clogher-Head and Smerwick-Bay District 
(County Kerry), on the scale of 3 inches to the mile. 
Discussion. 
Prof. Warts congratulated the Authors on this excellent paper ; 
it probably was merely an instalment of the work, which he hoped 
they would continue, of re-examining the less-known Ordovician 
and Silurian districts of Ireland. It appeared to be only in the West 
of Ireland that volcanic ashes and lava-flows were actually inter- 
bedded with Llandovery and Wenlock rocks. He would be glad 
of a clearer expression of opinion from the Authors in regard to 
one or two points. First, in regard to the occurrence of fossils of 
different horizons at one distinct horizon (spoken of by the Authors 
as Wenlock-Llandovery), he could hardly believe that zones so dis- 
tinct in England could be merged into one in Ireland. Was it not 
possible that, besides the proved inversion on a large scale, there 
were other phenomena of inversion and faulting on a small scale? ' 
Secondly, was it perfectly certain in this area that the igneous 
rocks were non-intrusive? Were there, for example, fossils in the 
tuffs and tufaceous fragments in the ordinary sediments? Finally, 
recalling that, among the specimens in the Irish Geological Survey 
Collections, he had seen and described intrusive rocks of Tertiary 
age in the South-west of Ireland, he asked whether there was also 
Tertiary volcanic material in the district worked over by the 
