4.36 Geological Society. 



breccia was deposited by water, and that subsequently to its formation 

 and prior to its elevation, it remained long under the waves. This 

 conclusion he believes to be justified by the appearance exhibited by 

 the sides of the cave, which in some parts are smooth and polished as 

 if long worn by water, and at others are perforated by Lithodomi. 

 In this opinion he considers himself fully borne out by a bone-breccia 

 lately discovered near the bay of Syracuse, about 70 feet above the 

 level of the sea, and deposited in caves worn in the tertiary rocks. 

 This breccia is of the same age as that at San Giro, contains the 

 bones of similar extinct quadrupeds, is intermixed with sea-shells, and 

 has not only been worn by water since its formation, but its substance 

 has been perforated by Lithodomi. From all these circumstances, 

 considered in conjunction with the extent of the preceding newest 

 tertiary deposits, the author considers it certain that the extinct qua- 

 drupeds, the bones of which are contained in the breccia, must have 

 lived at a period long posterior to that in which the Mediterranean 

 began to be inhabited by its present species of Mollusca, Radiata, 

 and Zoophytes, and before the last convulsion which raised a great 

 part of Sicily above the level of the sea. 



The caves at Beliemi were not so minutely examined by the author 

 as that at San Giro. In one respect they possess much interest. They 

 are situated at a greater height than the tertiary rocks have attained 

 in that neighbourhood; and neither the caves themselves nor the 

 bone-breccia have any appearance of marine action. The author 

 thence infers that the breccia at Beliemi was above the surface of the 

 sea at the time that the breccia at San Giro was beneath it ; and that 

 their present heights mark the extent to which the tertiary formation 

 at that part has been raised by the great convulsion^ by which a 

 large portion of Sicily has been elevated. 



8. The last formation noticed by Dr. Christie is diluvium, of which 

 he distinguishes two kinds differing in age. The older diluvium— an- 

 swering, he conceives, to the terrain de transport ancien of Elie de 

 Beaumont — consists of large rolled fragments of sandstone, with a 

 few fragments of the tertiary rocks cemented by a sandy clay, is of 

 the same age as the conglomerate and bone breccia, and occupies 

 considerable heights on the sides and summits of the hills. The newer 

 diluvium is quite distinct from the preceding, occupies only the bottom 

 of the valleys, sometimes to great depth, and consists partly of rolled 

 fragments of older rocks, even of the conglomerate, together with a 

 great quantity of grey clay. They may both be distinctly seen in the 

 valley of the Limetus. 



In addition to the general conclusions already mentioned in the 

 history of the bone-breccia, the author considers his observations as 

 affording complete confirmation of the views of Elie de Beaumont re- 

 garding the epochs of elevation of the Sicilian mountains. The prin- 

 cipal chain, extending across the island to the north of Gastro Novo 

 and Nicosia towards Messina, is not only sensibly parallel to the 

 principal chain of the Alps, whence alone, according to Elie de Beau- 

 mont, the date of elevation must be the same ; but the author con- 

 tends 



