384 
THE GEOICGIST. 
■white, Stand out well on the black ground of the limestone. We visited 
the shores of a beautiful lake some three miles from Florence Court, 
and, on the banks of the stream flowing from the Marble Arch, might 
have filled a cart with choice carboniferous fossils of the Calp series. 
One patch on the shores of the Lough was covered with the lovely 
grass of the Parnassus {Pcmiassia jmhistris), with its delicate cream- 
coloured flowers fringed with white nectaries. This Lough is famous 
for the fresh-water Astacus (or cray-fish), which grows hare to a large 
size. The heron rose lazily upon our approach, and groups of wild duck 
floated upon the waters. We made an expedition to the upper lime- 
stone district of Eon Naglin, west of Tlorence Court, and took the 
opportunitj'' of visiting one of the two original Ploreuce Court yews in 
the garden of a descendant of the discoverer, a tenant of the Earl of 
Enniskillen. The sister tree is at Florence Court, and from these have 
been propagated the now widely-cultivated Irish yew. This tree is a 
hyhrid, but how the hybridity was brought about is still a mystery. 
The old trees were found as dwarfiing plants, by the farmer who 
discovered them, on the very summit of Kulkeagh, a mountain of 
milstone-grit that covers up the upper limestone of Een Naglin. "We 
have no representation in our western districts of England either of the 
calp or the upper limestone series, so we would advise every geologist 
to pay attention to their development in the North of Ireland ; and, if 
time allows, to trace the rocks from Xnockshinny, on the west shore of 
Loch Erne, to Benbulben and Sligo. In the north of England (York- 
shire and Durham), these Irish limestones are represented by the Great 
Scaur series. The limestone of Ben Naglin supplies the collector of 
fossils with the somewhat rare Fentremites ovalis, an echinodermatous 
animal of the Blastoidea family, and shaped like a minute sea-urchin ; 
and the Tunbridge fern " Hymonoplujlhm Tunlndgense,'" grows upon 
the summit of the hill. A wild scene of heathery moor and moss 
stretches westvv'ard from the hill-top towards the coast. 
The traveller v/ould do well to ascend Kulkeagh by the way of the 
Marble Arch, where a fine wild dell is wrought by the rivulet which 
flows from the mountain to the lake. The Marble Arch is a sub- 
terranean cavern with the roof fallen in, and with wood, rocks, and 
gushing water, forms a highly picturesque and pleasant scene. Nearer 
Kulkeagh is another cavern, where one of our attendants informed us 
he had often distilled "potheen," and fried black trout and praties 
