DISCOVERED AT KIRKDALE, IN YORKSHIRE. 
5 
grey passing to black, are extremely fetid, and full of corals and 
spines of the echinus cidaris. The compact portions of this oolite 
partake of the property common to compact limestones of all ages 
and formations, of being perforated by irregular holes and caverns 
intersecting them in all directions; the cause of these cavities has 
never been satisfactorily ascertained: into this question (which is 
one of considerable difficulty in geology) it is foreign to my present 
purpose to inquire, any farther than to state that they were neither 
produced, enlarged, nor diminished by the presence of the animals 
whose bones we now find in them. The half-corroded fragments of 
corals, shells, and spines of echini, and the irregular ledges of lime¬ 
stone and nodules of chert that project along the sides and roof of 
this cave, together with the small grooves and pits that cover great 
part of its interior, show that there was a time when its dimensions 
were less than they are at present, though they fail to prove by what 
cause it was originally produced # . 
* 
* Caves in limestone are usually more or less connected with fissures of the rock in 
which they exist, and the solid matter that once filled them appears in many cases to 
have been carried off through the fissures by the long continued and gradual perco¬ 
lation of water, removing the softer or decayed portions of the rock, either in a state of 
solution or mechanical suspension, so that no traces of it remain at present either in the 
caverns or the fissures. 
I think it highly probable, from the description given by Tournefort, in his Voyage 
to the Levant, p. 53, and from the map and plan of it published in Sieber’s Travels in 
Crete, 1823, PI. 13, that the celebrated labyrinth of Crete was nothing more than a long 
connected series of natural caverns, such as we are now considering, a little assisted by 
art, and by the addition of a few corridors between the natural vaultings that compose 
this subterraneous wonder of classic antiquity. It is stated to occur in grey stratified 
limestone, which is found abundantly in Crete, and is full of caves and fissures. 
“ Through the whole island,” says Tournefort, “ there are a world of caverns, especially 
in Mount Ida, there are holes you may run your head in, bored through and through, and 
