Vol, 54.] EXPLORATION OF TY NEWYDD CAVES. 127 



excavated. Beyond this distance the gravel becomes more homo- 

 geneous and compact, being merged into the lowest compact gravel. 

 At 32 feet from the mouth, the combined thickness of the clays and 

 clayey gravels was 5^ feet, 



5. Compact gravel. This is the lowest bed that we have 

 excavated, and it extends throughout the whole cave, with a fairly 

 level surface, about 420 feet above sea-level, though it is higher 

 immediately over the large stone at the mouth. It is characterized 

 by the presence of subangular chert, but beyond 40 feet from the 

 entrance we could no longer find any clear line separating it from 

 the upper clayey gravel. 



At 24 feet from the mouth, and again at 44| feet, there were 

 vertical openings in the roof of the cave, reaching to the surface. 

 The first of these was free, except for a heap of stones below, 

 and one or two large stones and a little soil above. The sides 

 were very little worn by water, and it gave every sign of being 

 comparatively recent. The second opening was, however, larger 

 and with rounded sides. It was filled with drift right up to the 

 surface. 



Below the top soil, here very thin, there was a rough gravel 

 containing local stones, together with several quartzites and felsites 

 identified by Dr. Hicks as hailing from the Snowdonian area. We 

 also found a flint-pebble which, according to the same authorit)^, 

 can have come only from some northern source. 



At 5J feet from the surface this gravel was succeeded by a bed 

 of sandy to clayey gravel composed almost entirely of subangular 

 limestone-fragments, with a few small grains of the local grits 

 and patches of blue clay. This bed was 17 feet thick. Below 

 these came the ordinary succession which we had found through- 

 out, and this continued right across the opening, though slightly 

 disturbed by the deposit which had evidently fallen in through 

 the swallow-hole at a subsequent date to the general fiUing-in of 

 the cave. 



At 46 feet 10 inches from the mouth, and almost under this 

 swallow-hole, 18^ feet below the subangular limestone-deposit 

 (that is, 6 1 feet below our datum), we found a much- worn 

 fragment of tooth, which has since been identified at the Jermyn 

 Street Museum by Mr. E. T. Newton, F.E.S., as part of a lower 

 molar of rhinoceros. Unfortunately the species could not be 

 determined with certainty. 



Throughout the whole cave large blocks of limestone from the 

 roof and sides were met with in the upper beds, but the lower 

 portion of the walls had remained in place until we removed the 

 contents of the cave. 



Turning now to the longitudinal section (PI. YIII), I must first 

 point out that, although the general idea is correct, in some cases 

 we had to choose which beds to represent or omit, as they frequently 



