KiNAHAN — Killary Bay and Slieve Partry Silurian Basin. 707 
against the Silurians. Hereabouts the dips on the published one-inch 
maps are, unfortunately, confusing, as those in the Doolough slates 
represent the dip of the cleavage, and not the dip of the bedding. In 
the cliffs to the eastward of Doolough the unconformability is con- 
spicuous ; it is difficult of access near Doolough ; while to the west 
thereof the boundary is much obscured by drift and bog, and broken 
by heaves ; but still further westward, especially in the previously 
mentioned outliers, the unconformability is evident, the conglome- 
rates and sandstones lying nearly horizontal across the upturned edges 
of the old slates. 
On account of the boggy nature of the country only a few unsatis- 
factory actual junctions are exposed ; but the conglomerates containing 
fragments of the older rocks to the north ought to be sufficient proofs. 
As to the small outliers north and south of the Killary, these are very 
badly shown on the published maps, as the dips are not given in either 
the old rocks or the adjoining later ones. However, from the 
worked six-inch it could have been learned that the rocks of the 
Doolough series are perpendicular, or dipping at a high angle, 
while the Silurian dip northward at low angles, from nearly hori- 
zontal to 45° or 50°. 
The Ordovician exposure between the Great and Little Killaries 
(Salrock promontory) is bounded to the south by a fault, a downthrow 
to the south. These Ordovicians, as previously suggested by me, must 
have been a protruding ridge in the Silurian sea, against which the 
Silurians were deposited. In favour of this suggestion the fossils, 
according to Davidson's determination, go to prove that the " Salrock 
slates," although apparently the highest Silurian groups, was a littoral 
accumulation. Eut because there is now a fault in the Salrock Pass, 
it has been stated that the fossils in the Salrock promontory are 
not of Ordovician types, but of Silurian types. This is a question not 
for me, but for palaeontologists to determine. Harkness, King, and 
Baily, who were acquainted with the Ordovician fossils, not only of 
the Irish types, but of those all over the world, have pronounced 
them to belong to the Irish Ordovician types. I therefore put more 
faith in their judgment than in that of observers whose know- 
ledge of the fossil types of the Irish rocks necessarily must be very 
limited. Besides stratigraphical evidence goes to prove that their 
(Baily, &c.) determinations are right. 
We have now to consider the metamorphic rocks at Kilbride Bay, 
Lough Mask. These consist principally of gneiss and micalites. 
Between those on the north of the bay, and the fossiliferous Silurians 
