242 1>R0CEEDINGS OF THE GEOLOGICAL SOCIETY. [Maicll 24, 



2iid. Santonian stage: the lower part with Ostrea acutirostris, 

 0. santonensis, Spondylus truncatus, Janira quadricostata, SjphceruUtes 

 Coquandi, and Radiolites fissicostata. 



The upper part, of fluviatile origin, with Unio, CyclaSy Omphalia 

 Coquandi (Zekeli), and 7 beds of lignite, Cyrena glohosa and Ferussaci, 

 Math., Melanopsis rugosa, Math., and M. gdllo-provincialis. 



Plan d'Aups, near Sainte Baume, and the environs of Mar- 

 tigues. 



This corresponds to the upper portion of the chalk of Gosau. 



3rd. Campanian and Dordonian stages, from 400 to 500 metres, 

 equal to from 1333 to 1666 feet, of Lacustrine limestones, with Cyclas 

 gardanensis, Brongniartina, and gallo-provincialis, Math.., Ampullaria 

 prohoscidea, Math., Paludina angulata, Math., Lymnea longissima, 

 Math., &c., and containing 18 layers of lignites, very different from 

 those which are worked lower down, in the Santonian stage (fig. 3). It 

 is evident that these Lacustrine limestones correspond with the "Upper 

 Chalk " and with my Dordonian stage ; for they are covered by other 

 Lacustrine limestones, which 



, are referred to the level of the ^ig- '^.—Section of the Freshwater 

 limestone of Rilly, and there- Upper Cretaceous Beds of Fuveau. 

 fore to the base of the Eocene. 



Thus in Lower Provence it is 

 evident that a complete change 

 must have been wrought in the 

 nature of the waters of the 

 Cretaceous Sea, which, after 

 the conclusion of the Santonian 

 period, from being salt became 

 brackish, and afterwards, from 

 brackish, fresh — a circumstance 

 which favoured the develop- 

 ment of a population of flu- 

 viatile shells, entirely unknown elsewhere, and which were con- 

 temporary with the gigantic Eudistes of the Charente, and those 

 of Provence, which lived in the immediate vicinity of the lake, 

 at the bottom of which the Carbonaceous deposits were pre- 

 cipitated. 



The classification of these Lacustrine sediments had been, until 

 very lately, the cause of great confusion and serious errors. They 

 had been attributed at one time to the Miocene period, at another 

 to the Eocene, without a single reliable argument, or a single fossil 

 in support of this opinion. The new method of determining their 

 chronological order is justified, not only by their position, but also 

 by the very important fact that in the neighbouring Alps, as well as 

 in Algeria, where the upper chalk is exclusively of marine origin, we 

 observe, above the Santonian strata, Ostrea vesicularis and Belem- 

 nitella mucronata^ species wanting in the corresponding strata of the 

 Bouches du Rhone, which, as we have seen, having been deposited 

 in a lake, can only contain Lacustrine shells. My friend M. Mathe- 

 ron is occupied at the present time in making out a catalogue of this 



