M. Hubert — Comparison of Eocene Strata. 223 



freshwater basin of the Ehine, which had originally flowed from the 

 present site of Mayence to Basle, in a direction north, and south, 

 towards the great inland sea of Europe, must now have suddenly 

 changed their course from south to north, and, in escaping across the 

 barrier of Bingen, where a cataract of the most formidable and over- 

 whelming character must have been formed, would eventually press 

 forwards towards the inferior basins of Neuwied and Cologne, and 

 thence to the ocean, which then covered the present flats of Holland. 



J. M. 



in.— A Comparison of the Lower Eocene of Belgium and 

 England with that of the Paris Basin. By M. Hebert. 

 (Ann. Scien. Geologiques, vol. iv. art. 4.) 



IN this paper M. Hebert substantiates the opinion which he has 

 long held as to the position and succession of the Lower Eocene 

 strata in the above-named areas, and which is not quite in ac- 

 cordance with the views of other geologists. This subject has 

 already been treated of abroad, by MM. D' Archaic, Eaulin, and 

 Dewalque ; and in this country the valuable papers published in 

 1852 and 1855 by Mr. Prestwich and in 1866 by Mr, W. Whitaker 

 are doubtless well known to students of Tertiary geology. 



M. Hebert divides the Lower Eocene into Upper and Lower : 

 the former, according to this author, being represented in all three 

 countries ; whilst the lower is found only in France and Belgium, 

 and is wanting in England. 



The paper is divided into three parts, namely: — (1), the sands 

 of Bracheux and their equivalents in Belgium and England ; (2), 

 the beds comprised between the sands of Bracheux and the Calcaire 

 Grossier ; and (3), the beds comprised between the sands of Bracheux 

 and the Cretaceous series. 



1. — The sands of Bracheux constitute the equivalent of the Lower 

 Landenien of Dumont, and contain the following characteristic 

 species, which are foimd in both deposits, namely : — Panopcea 

 Vaudini, Desh., Thracia Prestivichii, Desh., Pholadomya cuneata, Sby., 

 Ph. KonincMi, Nyst, Cytherea fallax, Desh., Cyprina Morrisii, 

 Sby., Cucullcea crassatina, Desh.,. Pecten hreviauritus, Desh., Turri- 

 tella bellovacina, Desh., Natica Peshayesiana, Nyst. These sands 

 present two distinct fossiliferous horizons, that c>f Bracheux, and 

 that of Jonchery and of Chalons-sur-Vesle. The two beds are 

 well shown at the hill of Brimont, where they are divided by a 

 sandstone with vegetable impressions. At present, neither in 

 Belgium nor elsewhere is there any representative of this upper 

 zone. As to the lower horizon of Bracheux, it is not less apparent in 

 England than in Belgium, being there represented by the Thanet sands. 



Independently of Ph. cuneata, Ph. KonincMi, Cyp. Morrisii, Cue. 

 crassatina, cited above, and which are characteristic of the Thanet 

 sands, M. Hdbert has found at Bracheux and Heme Bay Psammobia 

 Edwardsii, Morr., and Corbula Regulbiensis, Morris ; at Chalons-sur- 

 Vesle and at Jonchery Cytherea orbicxdaris, Edw., and Scalaria 

 Bowerbanhii, Morris {fide Desh.) ; at Vaux-sous-Laon Pecten Prest- 



