218 LINE BETWEEN MIOCENE AND EOCENE. [Oh. XIV. 



the marine sands showed a much greater affinity to the subjacent 

 Eocene formations than to the more modern faluns of Touraine. 

 In his classical work on the fossil shells of the environs of Paris 

 (1824-'37) he had described twenty-nine species from the Fontaine- 

 bleau sands, of which some few could be identified with fossils be- 

 longing to the older Calcaire Grossier, whereas no one of them was 

 common to the faluns of Touraine. He also insisted on the general 

 aspect or fades of the fauna bearing a far greater resemblance to the 

 testacea of the older or Eocene group than to that of the faluns. 



A few years after the publication of my " Principles of Geology " 

 (vol. iii.) in 1833, the directors of the Government Survey of France, 

 MM. Dufrenoy and E. de Beaumont, referred the Paris gypsum in their 

 geological map of the Eocene, and the overlying marine sands and 

 Calcaire de la Beauce to the Miocene, the faluns of Touraine being re- 

 garded by them as constituting an upper division of the same Miocene 

 series. M. d'Archiac, in 1839, adopted the same method; and M. 

 Alcide d'Orbigny, in his Paleontology, in 1852, classed the Gres de 

 Fontainebleau, or " Sables Superieurs," as " Falunien A," and the faluns 

 of the Loire as " Falunien B," thus giving in his adhesion to the same 

 system of classification. That there should have been much differ- 

 ence of opinion on this subject was very natural, for, at the time when 

 I first took part in the controversy, there seemed very little prospect 

 of bridging over the wide gap between the two formations which it 

 was thus proposed to link together in one group. In 1857, by aid of 

 a railway cutting at Etampes, the number of marine shells derived 

 from the Fontainebleau sands was suddenly raised from 29 to 90 spe- 

 cies. The newly-discovered fossils furnished arguments both for and 

 against the views of those who desired to refer the strata containing 

 them to the Miocene rather than to the Eocene series. As bearing 

 against those views, may be mentioned the fact that none of the 90 

 shells agreed with species proper to the faluns of the Loire, while 

 some of them were identical with Calcaire Grossier species. This 

 was the more worthy of note because Etampes is within seventy miles 

 of Pontlevoy, near Blois, and not more than 100 miles from Savigne, 

 near Tours, two localities where the falunian shells are very abundant. 

 So striking a difference between the species of the valley of the Loire 

 and those of the basin of the Seine, when we consider the contiguity 

 of the spots above alluded to, could not be the result of geographical 

 distribution at one and the same era, but must evidently have depended 

 on a great difference in the age of the deposits. It marked the influ- 

 ence of Time, and not of Space. 



On the other hand, in favor of grouping the Etampes or Fontaine- 

 bleau sands with the newer Falunian rather than with the older Eocene 

 formations, M. Hebert pointed out that a majority of the 90 Etampes 

 and Gres de Fontainebleau fossils agreed specifically with shells which, 

 in Belgium, Mayence, and other localities, had been shown by the 

 labors of MM. Dumont, Nyst, De Koninck, and Bosquet to occupy a 



