180 Mr. De la Beche on the Geology of the 



Bay we find a few thick, light-brown and arenaceous beds, containing such 

 an abundance of small Nummulites, that the rock has sometimes the appear- 

 ance of being composed of them. They dip, highly inclined, to the E.N.E., 

 and rest on thick sandstone strata, which rest on marno-arenaceous limestone 

 full of Gryphites. The nummulitic beds also contain Pectens and Serpulae. 

 These beds re-appear in the direction of the strata in Bausi Raussi Bay ; 

 and their passage into the gryphitic limestone may there be seen, one bed 

 containing a mixture of Gryphites and Nummulites. The whole is subordinate 

 to the marno-arenaceous limestone of the vicinity, which both covers and 

 supports it. 



Marno-Arenaceous Limestone. ' 



This stratum occurs at St. Hospice, Mont Revel, Mont Gros, &c. &c. 



It is very variable in its nature. Sometimes the marly character prevails, 

 sometimes the arenaceous ; but the whole is so intimately connected, that it 

 cannot be separated. The colour is generally grey ; it is the 2nd limestone 

 of Mr. Allan, — the calcaire marneux stratifie or lias of M. RissOj and the 

 green-sand of M. Elie de Beaumont. 



Fossils. — Alcyonic bodies, almost always siliceous. 



Large Gri/phaa columba (bisulcata of M. Risso), chalcedoiiified ; central part of 



the thickness of the shell frequently calcareous spar. 

 Small Gryphites, numerouSj chalcedonified. 

 Echinites. 

 Pecten. 

 Nummulites. 

 Serpula. 



Inoceramus sulcatus. North side of Mont Gros ; discovered by M. Verany. 

 Turrilites. 

 Hamites compressus. — M. Risso. 



Ammonites. 1 g^^^^^ ^^^^ ^^ Grasse.— M. Martin du Martigues. 



Ustrea carmata. J 



A cretaceous bed in a valley marked on a lithographic map of the environs 

 of Nice, as the valley of St. Pons, contains black, cherty flints : this bed sup- 

 ports the tertiary conglomerates which are stratified horizontally. Good sec- 

 tions of the marno-arenaceous limestone are seen at the Peninsula of St. 

 Hospice, Mont Revel, Mont Gros, Valley of Falicon, Valley of St. Andre, 

 and the neighbourhood of La Trinite. 



Light-coloured Limestone with green grains. 

 This limestone occupies in general the lower part of the formation, though 

 it is sometimes interstratified with the marno-arenaceous limestone, described 

 above. 



