340 Reviews and Notices of Boohs. 



To this again succeeds the deep-water sedimentary beds of Mr 

 Roemer' s second group, the equivalents of our upper chalk. The 

 chalk formation of the south-east of England is nowhere complete i 

 even where thickest there is abundant evidence of the removal of 

 a much higher portion consisting of flinty chalk ; but whether, in 

 its upward extension over the English area, it subsequently under- 

 went any change in mineral character, can only be matter of con- 

 jecture. It is most probable that it did not. Over the Westphalian 

 area, on the contrary, the formation of the white chalk was followed 

 by a shallowing ; the result of which was that sandy beds, character- 

 istic of moderate depths, were formed above those of the deep-sea 

 chalk; and the zoological result is exhibited in the lists of marine 

 forms given by Mr Roemer, when we have the recurrence of a 

 fauna identical as to many characteristic species with one which 

 had previously existed over the same area at a long distant anterior 

 period, and confirming in a remarkable manner the accuracy of an 

 hypothesis advanced by Mr D. Sharpe (Geol. Jour, vol.x. p. 186.) 



Gault. — It had been generally supposed that this group was 

 not represented in the cretaceous series of Germany. In a rail- 

 way cutting near Neuenheerse a section was exposed in which 

 certain strata of a red sandstone overlaid true Neocomian beds, and 

 which from containing an ammonite supposed to be A. auritus has 

 caused the sandstones in question to be referred to the Gault. 

 With respect to the identity of the species, Mr Roemer admits, that 

 it does not altogether agree with the French and English forms. 

 Mr Roemer recognises the Gault at another place from the pre- 

 sence of A, interruptus ; but this shell would not be sufficient evi- 

 dence, and the distinctness of this group cannot as yet be consi- 

 dered to have been satisfactorily made out. 



C. The Neocomian — is the lowest cretaceous group, constituting 

 a long ridge along the Teutobergervald, but altogether wanting 

 on the south from the Rhine to Winnenberg. It is composed of 

 yellow and red sands, which were formerly supposed to belong 

 to the Quader sandstone ; but the discovery of a number of fossil 

 forms, as from Oerlinghausen and Bevergern, has determined its 

 true age and position. On the south, a little beyond Lichtenau, 

 these sandstones are found resting inconformably in the Triassic and 

 Jurassic beds there. Further north they mostly overlie clays con- 

 taining Cyrena majuscula and Milania strombiformis, well-known 

 forms of the so-called Weal den of North Germany. Its infra-posi- 

 tion to the whole of the cretaceous group of the district is also 

 shown by certain protruding ridges ; as the hill of Gildehaus near 

 Bentheim, and at Losser just within the Dutch province of Over- 

 yssel. The following forms are quoted from the several localities : — 

 Ammonites Decheni-bidichotomus, Belemnites subquadratus, Crio- 

 ceras Duvallii, Pecten crassitesta, Exogyra sinuata, Thracia Phil- 

 lipsi, Avicula cornueliana, Perna Mulleti. 



