90 
THE GEOLOGIST. 
of the instructive that is gained by the more adventurous tourist. I 
would therefore point out one or two places, not more than six or 
seven miles from that place, which few persons visit, and which 
none should return home without seeing. 
To the east of Killarney, at the foot of the cloud-capped Mangerton, 
there lies a rocky glen called " Glenacappul,"* or the " Horse's Glen." 
In it are three little mountain-lakes or " tarns," which generally 
appear as black as ink. The rocks are, the red, green, or grey grits, 
and slates of the old red sandstone. 
On walking down the glen from north to south, the strata are seen 
bent by numerous contortions, at both the top and bottom of the 
cliflf ; but midway, and interstratified with these beds, is a broad band 
of " igneous rock," the flexures and folds of which are similar to and 
coincident with those of the former. This igneous rock is a " felspathic 
trap," or " felstone," and is a compound of felspar and quartz. It is 
generally of a bluish green or whitish colour, very hard, sometimes 
containing crystals of white felspar, which, when large and numerous, 
give it a porphyritic character. 
At both the upper and lower surfaces of this band of trap, between 
it and the sedimentary rock, there are beds of flaky ash, of a green or 
yellowish green hue. 
The massiveness of the rocks, their contortions, the striking ap- 
pearance of the trap, the stately height of the clifl"s, the dark and 
gloomy waters of the three lakes — all combine in giving an unspeakable 
grandeur to Glenacappul. 
A couple of miles further east, and south of Lough Guitane — a pic- 
turesque lake situated on the southern side of the mountain-road leading 
from Killarney to Glenflesk — is another glen, called Cappagh Glen. 
Its sides are also lofty and rocky cliffs, and the band of trap inter- 
stratified with the sandstones on its western face presents much the 
same appearance as that in the Horse's Glen. Both in form and 
size the two glens are much alike ; but the wildness of the latter 
(in which patches of heath and a few ferns alone are seen) is com- 
pletely softened down in the former by the luxuriance of the 
natural wood, principally oak and holly, the abundance and size of 
the different species of ferns — from the lofty " Brake "f (Pteris 
* Cappul, Irish for " horse." 
t This fern grows hei-e to a height of more than ten feet. 
