174 
JOURNAL OF THE GEOLOGICAL SOCIETY OF DUBLIN. 
Wherever a good surface of the lower part of the felstone is ex¬ 
posed, whatever variety it may consist of, it is almost invariably 
marked by strong rough lines, which stand out in relief on the 
weathered surfaces, and run parallel to the lower boundary of the 
trap, and to the stratification of the grits and slates below. These 
lines or bands, sometimes half an inch or more across, look exactly 
like the harder bands of a gritstone that project on a weathered sur¬ 
face. On breaking open the trap, there is no apparent internal 
structure to correspond with them. I believe they are what the 
Germans call “ streckung.” They are often seen in thefelstones of 
Arenig and other parts of North Wales. 
The main mass of the Killarney trap is, as described by Mr. 
Foot, interstratified with and conformable to the sedimentary rocks, 
and partakes of all their accidents of contortion and dislocation. 
Some parts of it cannot be less than 600 feet thick, and may be 
much more; but other parts are not more than half that thickness. 
It is probable, though by no means certain, that the mass forming 
Benaunmore, where the great columnar ranges are, is the central 
nucleus or focus from which these igneous rocks originally spread. 
In conclusion, I would only add my testimony to that of Mr. 
Foot, as to the exceeding interest attached to a visit to these trap 
rocks, both for their geology and for the wild and picturesque 
beauty of the glens and valleys, on the sides of which they are to be 
seen, and which are more rarely visited by tourists than they de¬ 
serve to be. The view from the summit of Crohane (2162 feet), 
down, on to the craggy top of Benaunmore, with its two parallel 
glens, and its ranges of columnar cliffs, across the wild and rugged 
district of Old Bed Sandstone round the head of the Kenmare Val¬ 
ley, to Hungry Hill and Dursey Island on the left, and along the 
Killarney Mountains to Dingle Bay and Brandon Mountain on the 
right, over the limestone flat on which rests Lough Lean and 
Castlemaine—and on turning round along the mountain axis of Old 
Bed Sandstone hills, between the flat country of South Cork, com¬ 
posed of the Carboniferous slate, and the equally flat land of North 
Cork and Kerry, consisting of coal-measures,—to the distant heights 
of the Galtees, and where the Old Bed again rises from beneath,—is 
one of the most beautiful and most instructive in the neighbour¬ 
hood of Killarney. 
