§ 10. WEALDEN OF THE NORTH OF GERMANY. 377 



10. WEALDEN OF THE NORTH OF GERMANY. In the 



north of Germany, the Wealden formation has been 

 traced by M. Romer,* and other observers, over a con- 

 siderable part of Hanover, covering a large area to the 

 north of the Porta Westphalica, including the coal-field of 

 Biickeburg ; the impure coal of which resembles our Sussex 

 lignite. f These Wealden deposits lie upon the oolite, and 

 beneath the lowermost beds of greensand ; thus occupying 

 the same geological position as their English equivalents ; 

 the total thickness of the series is estimated at 800 feet. 

 Numerous characteristic fossils occur throughout these 

 strata ; and even the principal subdivisions of the Sussex 

 group have been distinguished. 



During the last year, a beautiful work on the Wealden of 

 the north of Germany, was published by Dr. Wilhelm 

 Dunker, (of Cassel,) in which are numerous important 

 additions to the fauna and flora of the country whence 

 the wealden deposits were derived. It contains figures and 

 descriptions of nearly fifty plants, and a still greater number 

 of shells, several fishes, and two new reptiles ; the plants 

 are chiefly ferns and cycadeae.J 



* Versteinerungen des Nord-deutschen Oolithen-Geberges ; by Pro- 

 fessor Romer : Hanover, 1836. In this work M. Romer enumerates 

 many fossils which distinguish the Askburnham (der Ashburnham 

 schichte), Hastings (der Hastings sandstein), Tilgate (Tilgat-stein), 

 and Weald clay ( der Wealder-thon), deposits. Cyprides, Paludinse, 

 Cyrenae, Cyclades, &c. are mentioned as universally prevailing through- 

 out the series. 



f See Fossils of the South Downs, p. 34. 



% Monographic der Nord-deutschen Wealdenbildung. Ein Bei- 

 trag zur Geognosie und Naturgeschichte der Yorwelt. Yon Dr. 

 Wilhelm Dunker. Brunswick, 1846. One vol. 4to. with twenty-one 

 plates. This beautiful volume will of course find its way into the 

 library of every geologist ; but I would also strongly recommend it to 

 the intelligent collector of organic remains, on account of the numerous 

 and excellent figures of Wealden plants, shells, &c. The work may be 

 obtained through M, Bailliere, Foreign Bookseller, Regent-si reet. 



