UPWARE AND BRICKHILL NEOCOMIANS. 71 



South of Mont Saleve, near Geneva, we meet with quite a 

 different type of Neocomian rocks with a fauna almost entirely- 

 distinct from our British forms, and indeed very different from the 

 north Swiss or Jurassian group. The great Diceras limestones 

 and Terehratula diphyes limestones and other Neocomian limestones 

 are enormous calcareous masses, making up in their simple thick- 

 ness such great mountains as Mont Yentoux, 1910 mbtres high, in 

 Provence. These beds are hardly separable in places from the 

 Jurassic limestones below or the Tertiaries above. 



Although there are so few common species to connect this 

 great Limestone series with our British Lower Greensands it is 

 still interesting to note the very wide range of some few of them, 

 such as Ammonites Martini, A. Deshayesii, and Belemnites pistilli- 

 formis which are recorded by M. Coquand from the province of 

 Constantine in Africa; while as many as 13 of our Up ware and 

 Brickhill species are known (Magnan) from the Urgo-Aptien beds of 

 the Pyrenees. 



Species common to the Ironsand Series and the 

 Neocomian of the Pyrenees (Magnan). 

 Terehratula sella, Shy.; Terehratula Moutoniana, d'Arch. 



Species COMMON to the Ironsand Series and the 

 Urgo-Aptien of the Pyrenees. 



Belemnites semicanaliculatus, Bl. Ostrea carinata, Sby. 

 Ammonites Deshayesii, Leym. „ {Exogyra) Tomheckiana, 



Pecten (Neithea) atavus, Boemer. d'Orb. 



Spondylus Roemeri, Desh. ] Terehratula sella, Sby. 

 Hinnites Leymerii, Desh. „ praelo7iga, Sby. 



Ostrea Couloni, Defr. „ pseudojurensis, Leym. 



„ macroptera, Sby. „ Moutoniana, d'Arch. 



North Europe. 



In Germany the cretaceous rocks occupy but a very small area 

 of the surface of the country. Sections or other exposures of the 

 Neocomian rocks are few and far between, and the relations of the 

 various rock series to one another are very difficult to determine, 

 so that I am by no means satisfied that any of the various theories 

 of correlations of these beds has been fairly established. The 



