174 CAVES AND CAVE DEPOSITS. 
The limestone on both sides of the little ravine which 
runs down into the Vale of Clwyd at Ffynon Beuno, near the 
village of Tremeirchion, is perforated with numerous caves and 
cavernous places. One face of rock in particular has much 
interest attached to it, owing to the excavations which have been 
recently carried on in it by Dr. Hicks and Mr. Bouverie 
Luxmoore, whose interpretation of the observations made 
involves various questions still under discussion. The first 
notice of these caves that I know of is in the report of an 
excursion of the Chester Natural Science Society (see Chesfer 
Courant, July 26, 1883.) The caves coincide more or less with 
lines of joint and faults along which calc spar and various 
minerals suggested the possibility of lead ore. Trials had 
therefore been made in the cave, and the cave earth had been 
turned over in places. The fragments of bone lying about 
were sufficient to suggest that the sheep and fox of to-day 
must have been once represented by the stag and hyena. I 
proposed to the Society to open the caves if permission could 
be obtained, and foretold the probability of our obtaining in 
them the remains of primeval man. The following year a 
member of the Chester Society, Dr. Hicks, excavated near the 
mouth of the lower cave and obtained such interesting results 
that he applied for a grant first from the Royal Society and 
afterwards from the British Association to enable him to carry 
“on the explorations, the results of which he has laid before 
the Association, and other scientific societies. As I have 
explained above, there is inside of, and more especially at the 
mouth of most caves, a breccia consisting of angular fragments 
which have fallen from the rock, while the cave was exposed to 
changes in the amount of moisture and in the temperature. 
Sometimes the mouth is blocked by a perfect barricade of large 
blocks which have fallen from the face of the rock where most 
exposed. This was very conspicuous at Plas Heaton. At 
Ffynon Beuno, however, the fragments were small. This depends 
much upon the extent to which the rock is traversed by joints. 
The fragments are generally embedded in cave earth, some of 
which is the red earthy residuum of the decomposed limestone. 
In the Cae Gwyn cave, that is the upper cave at Ffynon Beuno, 
this limestone breccia consisted of large masses of rock which 
had broken down and lay on the cave deposits containing bones. 
Just within this newly-exposed opening into the cave under a 
projecting mass of rock, which was removed with a view to 
making steps up to the surface of the ground outside, Dr. Hicks, 
Mr. Morton, and the workman saw a flint flake taken out from 
the bed of limestone breccia in which bones occurred. A 
similar deposit extended under the sandy drift with boulders as 
far out as the excavation was then carried. This is conclusive 
against the drift which rested on it being shore deposits of the 
undisturbed marine Clwydian drift, as it is quite impossible that 
the lashing waves on a rock-bound shore, exposed to the North- 
west winds, should not have swept such loose debris into the 
deep fiord below. That is probably why we have not yet and 
