1844.] 403 



rine JVealden" (Veldien Marin) wliich would at once indicate its 

 position, and its peculiar relations.* 



§. Tlie lower cretaceous series on the Continent, which probably 

 bears the greatest analogy to ours, is that of Hanover, described by 

 M. Von Rosmer. Though differing at the upper part from ours by 

 the absence of the Gault, the cretaceous series at the bottom is well 

 defined, reposing on a comj^lete equivalent of our Wealden, witli 

 nearly all the characteristic fossils of Surrey and Sussex. It is not 

 easy to identify the upper member, which M. Von Roemer supposes to 

 be the same as the upper pai^t of our Lower Green-sand, but which 

 contains a great variety of fossils, and possibly may include some 

 higher portions of the chalk. 



Tlie '■^Hils-conglomerat" of Von Roemer contains some fossils iden- 

 tical with those of our Lower Green-sand, and some with the Neoco- 

 mian, which he distinguishes from that division. It is supposed to 

 rest upon the lower clay of Hils (Hils-thon), but has not been seen 

 in apposition with it. Lastly, the Hils-thon is identified by its fossils 

 with the Speeton clay f, and seems to correspond exactly with the 

 clay of Atherfield, Hythe, and Surrey. Having had the pleasure 

 of seeing M. Von Rcemer in his own country during the progress of 

 his work, and having mentioned to him the probable identity of our 

 Atherfield clay with that of " Hils," lam glad to find (p. 132.) | 

 that he has adopted this identification. He has shown that the 

 Hils-conglomerat and this clay are in Hanover distinctly superior 

 to the Wealden (Walder-thon); a fact of importance, coinciding 

 with our own sections in proving that the Neocomian (or that part 

 of it at least which is identical with the Hils deposits), cannot be 

 contemporaneous with the Wealden, upon which it is found to 

 repose. 



The Hanoverian series is farther interesting to the English 

 geologist, as demonstrating that the fresh-water deposits contem- 

 poraneous with our Wealden were not quite of such limited extent 

 as has been supposed. § 



No limestone like that of Kent has been found in Hanover ; and 



* It may be worth while to ascertain by exact search in the department of 

 the Aube, whether traces of the Wealden itself do not exist there below the Neo- 

 comian strata of M. Leymerie. It is stated by M. Dufresiioy that he had 

 seen such indications near Angouleme ; and they exist, according to M. Passy, 

 in the vicinity of Beauvais, Pays de Bray. (See Bulletin de la Soc. Geol. de 

 France; and Geol. Trans, vol. iv. p. 327.) 



-f- Mr. Austen has recently expressed the same view respecting this clay, on dif- 

 ferent and independent evidence. — See Proceedings of Geol. Soc. June, 1843, 

 vol. iv. p. 196. ; but Professor Agassiz had previously assigned its correct place 

 to the Speeton clay, having stated its identity with the Neocomian clay of Neuf- 

 chatel, at a meeting of the Geol. Soc. of France, April 16. 1838. Bulletin, &c. 

 ix. p. 262. 



\ The work of M. Von Rcemer here referred to, " Die Versteinerungen des 

 norddeutschlichen Kreide Gebirges," was published in Hanover in 1841. 



§ In the work of M. Geinitz, on the Fossils of the Saxon Cretaceous Hills, 

 (Dresden, 1839 to 1842,) it is intimated that the Wealden occurs below the 

 cretaceous series in that country. 



VOL. IV. PAET II. H H 



