by means of ladders and ropes.  Instead of walls and a roof of solid limestone rock we found shattered masses apparently held together by breccia, also of a reddish colour and full of fragments of bones. (Plate 45.) The opening in the surface appears to have been formed by the subsidence of these rocks at the time when they were hurled down, mixed with breccia, into the position which they still retain.  Bones were but slightly attached to the surface of this cement, as if it had never been in a very soft state, and this we have reason to infer also from its being the only substance supporting several large rocks and at the same time keeping them asunder.  On the other hand we find portions of even very small bones, and also small fragments of the limestone, dispersed through this cementing substance or breccia.

FIRST DISCOVERY OF BONES.

The pit had been first entered only a short time before I examined it by Mr. Rankin, to whose assistance in these researches I am much indebted.  He went down by means of a rope to one landing-place and then, fixing the rope to what seemed a projecting portion of rock, he let himself down to another stage where he discovered, on the fragment giving way, that the rope had been fastened to a very large bone, and thus these fossils were discovered.  The large bone projected from the upper part of the breccia, the only substance which supported as well as separated several large blocks, as shown in the accompanying view of the cave (Plate 45) and it was covered with a rough tuffaceous encrustation resembling mortar.  No other bone of so great dimensions has since been discovered within the breccia. (See Figures 12 and 13, Plate 51.)

From the second landing-place we descended through a narrow passage between the solid rock on one side and huge fragments chiefly supported by breccia on the other, the roof being also formed of the latter and the floor of loose earth and stones.

SMALL CAVITY AND STALAGMITIC CRUST.

We then reached a small cavern ending in several fissures choked up with the breccia.  One of these crevices (K.  Plate 44) terminated in an oven-shaped opening in the solid rock (Plate 50) and was completely filled in the lower part with soft red earth which formed also the floor in front of it and resembled that in the large cavern already described.  Osseous breccia filled the upper part of this small recess and portions of it adhered to the sides and roof adjoining, as if this substance had formerly filled the whole cavity.  At about three feet from the floor of this cavity (Plate 50) the breccia was separated from the loose earth below by three layers of stalagmitic concretion, each about two inches thick and three apart; and they appeared to be only the remains of layers once of greater extension, as fragments of stalagmite adhered to the sides of the cavity as shown in Plate 50.  The spaces between what remained of these layers were filled with red ochreous matter and bones embedded partially in the stalagmite.  Those in the lower sides of the layers were most thickly encrusted with tuffaceous matter; those in the upper surfaces on the contrary were very white and free from the red ferruginous ochre which filled the cavities of those in the breccia, although they contained minute transparent crystals of carbonate of lime.