410 REPORT—1899. 
considerable quantities of sand and with the underlying local gravel. 
Whether the floor at Ffynnon Beuno was similarly broken through we 
cannot now tell, but the floods cannot have been very severe, as so small 
a portion of the Ty Newydd floor was taken away. Mr. A. Strahan 
detected some striated stones in the gravel belonging to this part of the 
series, thus indicating the presence of glavial conditions. 
E. All these earlier beds in Ty Newydd were covered over by a thin 
bed of clay, which, although of no importance in itself, was of great use 
in providing us with a clear line of separation between the various 
formations. Above this clay bed, in the southern and middle portions of 
Ty Newydd, we found a deep deposit of limestone breccia in clay which 
reached nearly to the surface. In each place where this was present we 
also observed that the roof was wanting, and the abrupt termination of 
the cave walls implied that they formerly extended some feet higher 
before arching over. The removal of the roof must have been subsequent 
to the formation of the stalagmite, as it is absent over nearly the whole 
length of the floor. 
The breccia was so compact that in several places it was difficult to 
distinguish it from rotten portions of the cave wall. Many of the blocks 
were over 2 cwt., and in no case was the appearance of the bed such as to 
imply a simple falling in of the roof, but it rather indicated that con- 
siderable force had been applied. 
This powerful agent appears to have been identical with the force 
which disturbed the bone beds of Ffynnon Beuno and Cae Gwyn, breaking 
up the floor and redepositing the fragments with the fossils in a clay 
matrix.! 
F. The succession hitherto discussed is chiefly founded on the deposits 
in the southern half of Ty Newydd western cave. The laminated sandy 
clay or clayey sand which followed was very poorly represented at the 
higher levels of this cave, but in the lower northern portion, in the eastern 
cave, and in the last excavation made under the old lead shaft this deposit 
was found in great abundance. Its true place in the succession is proved 
by the excavations at Cae Gwyn,? where it completely covers over the 
redeposited bone beds. 
To this deposit we must add the sandy beds with marine shells dis- 
covered at the northern extremity of Cae Gwyn cave.? 
G. Over all the deposits in the caves, and in several places in direct 
contact with them, there is spread over the valley a considerable thickness 
of boulder clay, containing the only local stones which have glacial striz, 
and also having a large admixture of erratics.* 
The above correlation, though only put forward as a suggestion, yet 
cannot be denied some probability, especially when it is remembered 
that only a few hundred fect separate all the excavations, and therefore 
the same agents must have been at work on each. 
1 O.JS.G.S. 1886, p. 15, * Ibid. 1888, p. 574, fig. 5. 
3 Tbid. p. 567. See also a paper in the same volume by Prof. T. M‘Kenny Hughes, 
p. 119. 
+ See Q.J.G.S. 1898, p. 120. In the paper read before the British Association at 
Bristol, it was stated that the results of Mr. Strahan’s examination show that about 
one half is local material, much of this being clearly striated. , . . Of the erratics the 
greater part consists of felsites, &c., whose source could not be determined, while 
the residue contains about equal proportions of felsites from the Snowdon area, and 
of granite from Cumberland or Scotland. With these are a few cretaceous flints, 
perhaps from the North of Ireland. 
