Environs of Nice, and the Coast thence to Vintimiglia . 183 



various shades of grey or light brown : the stratification is indistinct, some- 

 times imperceptible. 



Fossil remains are exceedingly rare, as has been observed by Mr. Allan, in 

 both these rocks. He mentions an Ammonite, an Echinus, a Pecten, and Corals : 

 the latter are in great abundance near the light-house at St. Hospice. Perhaps 

 the Echinus may have been an Encrinus, as there is little difference in the frac- 

 ture of these fossils. The rest of the organic remains which he enumerates 

 belong, I believe, to the green-sand formation. In the limestone now under 

 consideration, I have observed only, here and there, a solitary Terebratula. 



, Gypsum. 



To the same formation I am disposed to refer the gypsum found along the 

 southern slope of the Cimiez ; for its apparent continuation at the base of the 

 Venagrie is included in the dolomite and light-coloured limestone, as is also 

 the gypsum of the Requiez. It is of various shades of grey and red, gene- 

 rally more or less crystalline, with little coherence, and rather massive than 

 stratified. 



There would not appear to be any regular order in which the dolomite and 

 limestone are disposed; they are so singularly mixed, that it is impossible to 

 calculate upon the occurrence of dolomite in any particular part of the series : 

 when the latter is very crystalline and stratification has ceased, it has some- 

 times even the appearance of an intruded mass. 



I agree with M. Brongniart in considering these beds of limestone, dolo- 

 mite, and gypsum, the representatives of the Jura limestone, which occurs 

 extensively along the western side of the Alps, from Geneva to the Mediter- 

 ranean. That the compact limestone near Nice closely resembles that of the 

 Saleve has been already noticed, and the Saleve limestone is usually considered 

 synonymous with the oolite range of England. 



These limestones, dolomites, and gypsums, are so intimately associated, that 

 no rational classification can disconnect them. In this respect they agree 

 entirely with those great ranges of rock which traverse the Tyrol, Carinthia, 

 Stiria, and the North of Italy, and probably Dalmatia, as described by Von 

 Buch, Marasciiini, and Fortis. Von Buch's theory of the change of common 

 limestone into dolomite, by the escape of magnesia from the subjacent 

 pyroxenic rocks, and of the disturbance of the strata wherever this change 

 has taken place by the protrusion of pyroxenic porpliyry and trap, if true hi 

 regard to the Tyrolese rocks, may be applicable to the maritime Alps. 



In the immediate neighbourhood of Nice, it is true, no trap rocks have as 

 yet been discovered, though there is no want either of trap or porphyry among 



