516 Zoological Proceedings of Societies. 



lower part, and the magnesian above. This spot, therefore, affords evi- 

 dence of four distinct epochs. 1. When the sea, higher than at present, 

 introduced Lithodomi into the fissure. 2. When the lower part of the fis- 

 sure was filled with pebbles transported from a distance. 3. When its 

 upper part was filled with the broken bones of animals, shells terrestrial 

 and marine, and with fragments, principally but not solely, of contiguous 

 rocks. 4. When the sea attained its present level. 



The fossils under the breccia seem to have been quietly deposited by a 

 sea that stood several feet higher than the present Mediterranean. To ex- 

 plain this difficulty, some authours imagine that the Mediterranean has 

 sunk, by forcing its passage through the Straits of Gibraltar ; but this sup- 

 position the authour conceives to be improbable. 



Tertiary rocks consisting of sand, sandstone, and a conglomerate of 

 various rolled pebbles, shell marl, calcareous gritstone and breccia, and 

 gray marl, occupy an extensive area on the west and north- west of Nice. 



The shell marl here mentioned is that which Brocchi has described ; 

 and it contains, in the Sub- Alps, the same fossils as in the Sub-Appenines. 



In the calcareous breccia are angular pieces of the contiguous limestone 

 and dolomite perforated by Lithodomi ; adhering to which are sometimes 

 found the lower valves of Spondyli, quite perfect, notwithstanding the 

 delicat^ texture of their edges. The cement contains three species of 

 Pecteni; with remains, perhaps, of a Saurian. Care must be taken not 

 to confound this latter breccia, which rises more than a thousand feet 

 above the sea, with the diluvial breccia above described. 



On reviewing the tertiary beds, the authour remarks in their probable 

 history three distinct epochs; viz. two of repose, and one of violent dis- 

 turbance. 



The Secondary rocks of Nice consist of two great formations; the 

 upper one composed of siliceous, argillaceous, and calcareous particles 

 intimately mixed, but in very variable proportions; some of the beds 

 abounding in green grains; which circumstance, together with the nature 

 of their fossils, induces the authour to rank the formation to which they 

 belong with the green -sand of England. NummuHtes, however, which 

 are rarely found in the green-sand of this country, are found plentifully in 

 that of Nice. The strata are very much disturbed and contorted; so that 

 an unguarded observer might often suppose them to be inferior to rocks 

 on which they are in reality incumbent. 



