Ch. XI.] 



BRECCIAS IN SICILIAN CAVES. 



141 



wide. It occurs in a secondary limestone, in the Monte 

 Grifone, at the base of a rocky precipice about 180 feet above 

 the sea. From the foot of this precipice an inclined plane, 

 consisting of horizontal tertiary strata, of the newer Tliocene 

 period, extends to the sea, a distance of about a mile. 



No. 27. 





a, Monte Grifone. 

 6, Cave of San Giro. 



c, Plain of Palermo. 



d, Bay of Palermo *. 



The limestone escarpment was evidently once a sea-cliff, and 

 the ancient beach still remains formed of pebbles of various 

 rocks, many of which must have been brought from places far 

 remote. Broken pieces of coral and shell, especially of oysters 

 and pectens, are seen intermingled with the pebbles. Imme- 

 diately above the level of this beach serpulae are still found 

 adhering to the face of the rock, and the limestone is perforated 

 by lithodomi. Within the grotto also, at the same level, simi- 

 lar perforations occur, and so numerous are the holes, that the 

 rock is compared by Hoffmann to a target pierced by musket 

 balls. But in order to expose to view these marks of boring- 

 shells in the interior of the cave, it was necessary first to remove 

 a mass of breccia, which consisted of numerous fragments of 

 rock and an immense quantity of bones imbedded in a dark 

 brown calcareous marl. Many of the bones were rolled as if 

 partially subjected to the action of the waves. Below this 

 breccia, which is about 20 feet thick, was found a bed of sand 

 filled with sea- shells of recent species, and underneath the 



* This section is given by Dr. Christie, as of the Cave of San Giro. Ed. New 

 Phil. Journ., No. xxiii. Its geographical position and other characters agree so 

 precisely with that of Mardolce, described by M. Hoffmann, that it may be ano- 

 ther name for the same cave, or one immediately adjoining. 



