UNDER VAULTINGS FILLED WITH MUD AND BONES. 115 
Along the edges of this floor are seen a number of smaller 
caverns, which pass off from the main chamber to various distances 
in the body of the rock; the bottom of these is filled also with the 
same materials that cover the floor of the great chamber. Beneath 
the latter are also numerous undervaultings, and small branching 
catacombs of irregular shape; (see h. i ;) some terminating in a cul 
de sac, others communicating by a lateral aperture with some ad¬ 
jacent cavity, which again has further communications either with 
the main chamber above, or with other smaller ones below, so that 
the rock is intersected and undermined like an irregular mass of 
honeycomb. These undervaultings have for the most part been en¬ 
tirely filled up, as at i, with a mass of brown earth, or diluvial loam, 
through which, as their matrix, are disseminated enormous quantities 
of broken bones, teeth, angular fragments and pebbles of limestone. 
In the cavities thus choked up there is no room for any stalagmitic 
crust, as there is no expanded surface over which it could be spread. 
The mass which fills them, however, is in some parts fir ml y cemented 
together by stalagmitic infiltrations of calc sinter; more frequently 
the mud is semi-indurated, spungy, and cellular, and may be readily 
cut with a knife; in other parts it is quite soft and loose, and the 
bones and pebbles are simply imbedded in it. 
These lower vaults have in no case that I could find been laid 
open to their full extent, but are still choked up below with matter 
of the nature above described, and would no doubt richly repay the 
labour of any person who has leisure to explore them. The excava¬ 
tions that have been made in them have produced small artificial 
caverns, the sides and roof of which are crowded with, and sometimes 
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