20 On certain Newer Deposits in Sicily, 



caverns, but in a very different state from those just described. 

 They form a true bone-breccia, having a very hard basis of a 

 blue or grey Hmestone, with irregular patches in various places 

 of an equally hard rock, made up of fragments of sea shells and 

 corals *. This cavern has a long narrow entrance from the 

 base of the inland cliff, its length being about 130 feet, and its 

 breadth only 20, terminating in a circular cave, whose diame- 

 ters, in different directions, vary from 60 to 80 feet. The bone^ 

 breccia is only found in the entrance, and appears to have been 

 much worn down since its first formation, for it is higher at its 

 sides than middle, and the smooth water-worn appearance of 

 its surface, and the fact of its having been pierced by lithodomi, 

 throughout nearly its whole length, shew that it had not been 

 worn down by artificial means. No excavations appeared 

 to have been made in this cave before I was there, and the 

 above appearances having excited my most lively interest, I 

 immediately procured the assistance of a labourer, who could 

 only detach with his pick-axe the few, but I hope satisfactory, 

 fragments which I send with my other specimens to the Socie- 

 ty. I next examined the outside of the caves, and was delight- 

 ed to find that the analogy between this and the caves at Paler- 

 mo was still kept up, by the breccia extending for a great dis- 

 tance along the ground, at the base of the cliff. My time 

 would not permit me to trace its extent, which must, I should 

 suppose, be considerable, for I observed it at several points at 

 a great distance from each other. I entered several other caves, 

 but it was only in one of them that I could detect any thing 

 like a deposit of a more recent date than the tertiary rocks, in 

 which they are situated. That to which I allude is a long ir- 

 regular-shaped cavern, the entrance of which contains on its 

 floor, and extending some way up its sides, a calcareous yellow 

 breccia, principally made up of broken shells and small frag- 

 ments of Hmestone, but containing no bones, although there 

 can be no doubt that it belongs to the same formation, and the 

 absence of bones in this cave, or, perhaps, to speak more cor- 

 rectly, their presence in the other, must be considered acci- 

 dental 



• M. Brongniartj in his " Tableau des Terrains/' says, " Autres les os on y 

 trouve des coquilles qui sont toujours terrestres, fiuviatiles et lacustres." , 



