6 On certain Newer Deposits in Sicily, 



evident by the details that follow. The breccia is not merely 

 confined to the cavern, but also forms a great part of the exter- 

 nal talus, along which it extends (according to Professor Scina) 

 for more than 9>QQ feet, and is there associated with beds of 

 diluvium, and rests upon the tertiary rocks with recent shells 

 which have been already described. The interior of the cavern 

 having been completely excavated, and the breccia removed, we 

 can now only give an account of the arrangement met with in 

 the external talus ; but it is extremely probable that the beds 

 composing the latter extended originally into the cavern ; and 

 in regard to most of them, indeed, we may say that this is cer- 

 tain, for we can still observe the stain left by them upon the 

 walls. A deep trench has been cut from the entrance of the 

 cave through the upper part of the talus, which, together with 

 the excavations in the interior, and the exposed part on the road 

 below, afford us a distinct and accurate section of the whole. 

 Immediately under the vegetable soil of the talus, are numerous 

 large blocks of limestone, imbedded in reddish clay, the whole 

 having a thickness of about 6 feet. These blocks are seen all 

 along the face of the talus, and are exposed on the road below, 

 where they appear to rest on the tertiary beds, as indicated in 

 accompanying section, Plate I. 1. 



Similar blocks are met with in various situations in the neigh- 

 bourhood of Palermo, the most considerable of which is one 

 which extends along the western shore of the bay near the foot 

 of the Monte Pelegrino for the space of about a mile, and hav- 

 ing a thickness of 40 or 50 feet. The blocks, which are of 

 great size, some of them being many yards in circumference, 

 are all of limestone, and are united by a coarse calcareous con- 

 glomerate, which having rather a loose texture, numerous ca- 

 verns have been hollowed out in it by the waves, and are known 

 by the name of the Grotte dell' Arenella. This great deposit 

 rests on beds of tertiary limestone, which here do not reach the 

 kvel of the sea. (PL IL Fig. 1.) But to resume our descrip- 

 tion of the talus : Under the blocks we find a bed of reddish 

 clay, mixed with a little Hme, and containing small rounded 

 fragments of limestone and quartz, with a few bones, (PI. I. 

 3.) ; beneath which is the true bone-breccia, having altogethe 

 a thickness of about 20 feet. (PL. I. 4.) It has some ap- 



