Dr. C. Striickmann — The Jura of Hanover and England. 5i9 



beds and the Coralline Oolite almost everywhere display a very 

 similar fauna, whilst the development of local faunas commences 

 with the Kimmeridge, so that, in the case of the higher deposits of 

 the Upper Jura, the palceontological material alone does not suf&ce 

 for comparison and correlation. 



2. From the Lower Calcareous Grit (including the upper region 

 of the Oxford Clay with Ammonites cordatus, A. athleta and Ostrea 

 dilatata) and the Lower Limestone, 24 species, and among them 12 

 Conchifera, 4 Cephalopoda, and 4 Echinoida, occur also in the 

 Hanoverian Jura. 



a. Of these 24 species, 16 occur in the Hersumer beds of Han- 

 over, and 6 of these {Thracia pinguis, Belemnites hastatus, Am- 

 monites cordatus, A. arduennensis, A. perarmatiis, and A. athleta) have 

 not hitherto been found in any higher beds, while the other 10 

 species also occur in the Coralline Oolite. It is further to be re- 

 marked that in England 20 of these 24 species belong in common 

 to the Lower and Middle Calcareous Grits, whilst only 3 species are 

 confined to the lowest zone. 



b. The other 8 species do not occur in Hanover in the Hersumer 

 beds, but in the Coralline Oolite, — 6 in the Lower and 2 in the 

 Upper Coralline Oolite. Considering the near affinity of the 

 inferior zones of the Upper Oolite both in England and in 

 North Germany, this is not at all surprising. On the contrary, 

 from the conditions of stratification and the close palgeontological 

 relationship, it cannot be doubted that the Lower Calcareous Grit 

 and the Lower Limestone together, and including the upper region 

 of the underlying Oxford Clay, represent the North-German Her- 

 sumer beds, i.e. the South-German zones of Ammonites hiarmatiis 

 and A. transversarius, taken together. No separation of the Her- 

 sumer beds into two zones is practicable in North Germany, so 

 far as my observations go. 



3. The Middle Calcareous Grit, including the Coralline Oolite 

 and Coral Eag, contains the great number of 68 species of fossil 

 remains of animals, which also occur in the Upper Jura of Hanover, 

 and among them 6 Corals, 15 Echinoids (or the whole of the known 

 common species), 6 Cephalopods, 28 Bivalve Mollusca, and 11 

 Gasteropods. 



a. Of these 68 species there are : — 



In the Hanoverian Coralline Oolite generally 57 species. 



Only below, i.e. in the Hersumer beds 6 ,, 



Only above the Coralline Oolite 5 ,, 



Of the first-mentioned 57 species, 16 have hitherto been found 

 near Hanover only in the Coralline Oolite, and among them are : — 

 Cidaris finrigemma, Hemicidaris intermedia, Pygurus pentagonalis, 

 Stomechinus gyratus,^'' Echinohrissus dimidiatus,'-'' Emarginulina Gold- 

 fussii,^-'' Turbo princeps,^'-' Fhasianella striata, Natica Clio, and 

 Nerincea visurgis. 



The species marked with an asterisk are also limited to this 

 division in England so far as is at present known. 



