218 Royal Socicty. 
The den is a natural fissure or cavern in oolitic limestone ex- 
tending 300 feet into the body of the solid rock, and varying 
from two to five feet in height and breadth. Its nouth was 
closed with rubbish, and overgrown with grass and bushes, and 
was accidentally intersected by the working of a stone quarry. 
It is on the slope of a hill, about 100 feet above the level of a 
small river, which, during great part of the year, is engulfed. 
The bottom of the cavern is nearly horizontal, and is entirely 
covered to the depth of about a foot, with a sediment of mud 
deposited by the diluvian waters. The surface of this mud was 
in some parts entirely covered with a crust of stalagmite; on the 
greater part of it there was no stalagmite. At the bottom of 
this mud, the floor of the cave was covered from one end to the 
other with teeth and fragments of bone of the following animals : 
hyena, elephant, rhinoceros, hippopotamus, horse, ox, two or 
three species of deer, bear, fox, water-rat, and birds. ; 
The bones are for the most part broken, and gnawed to pieces, 
and the teeth lie loose among the fragments of the bones ; a very 
few teeth remain still fixed in broken fragments of the jaws. 
The hvena bones are broken to pieces as much as those of the 
other animals. No bone or tooth has been rolled, or in the least 
acted on by water, nor are there any pebbles mixed with them. 
The bones are not at all mineralized, and retain nearly the whole 
of their animal gelatin, and owe their high state of preservation 
to the mud in which they have been imbedded. The teeth of 
hyznas are most abundant; and of these, the greater part are 
worn down almost to the stumps, as if by the operation of gnaw- 
ing bones. Some of the bones have marks of the teeth on them ; 
and portions of the fecal matter of the hyenas are found also 
in the den. These have been analysed by Dr. Wollaston, and 
found to be composed of the same ingredients as the allum 
graecum, or white feces of dogs that are fed on bones, viz. car- 
bonate of lime, phosphate of lime, and triple phosphate of am- 
monia and magnesia; and, on being shown to the keeper of the 
beasts at Exeter Change, were immediately recognised by him 
as the dung of the hyena. The new and curious fact of the 
preservation of this substance is explained by its affinity to bone. 
The animals found in the cave agree in species with those that 
occur in the diluvian gravel of England, and of great part of the 
northern hemisphere; four of them, the hyzna, elephant, rhino- 
ceros, and hippopotamus, belong to species that are now extinct, 
and to genera that live exclusively in warm climates, and which 
are found associated together only in the southern portions of 
Africa near the Cape. It is certain from the evidence afforded 
by the interior of the den (which is of the same kind with that 
afforded by the ruins of Herculaneum and Pompeii) that all oe 
animals 
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