103 The Lower Cretaceous Floras of the World 



The Neocomian marks the culmination of the upper Jurassic emer- 

 gence, and is emphasized by littoral, estuarine and various types of conti- 

 nental deposits, such as the Morrison and Kootanie of the west and the 

 Wealden of Europe. Marine deposits continue uninterruptedly along the 

 Pacific coast of both North and South America, the Cretaceous iiora 

 being observed for the first time in the upper portion of the Knoxville 

 beds in the former area. The Neocomian sea of Mexico appears not 

 as yet to have reached the international boundary. 



Deposits of this age are typically developed in southern Europe and 

 northern Africa. The eastern and southern coasts of Africa were also 

 receiving sediments as well as a large area in southern Asia. Eastern 

 Greenland shows Neocomian deposits, and an arm of the sea extends 

 southward across central Eussia (Petchorian). Along the eastern coast 

 of North America the initial transgression of the Cretaceous sea is not 

 recorded in outcropping deposits of a typically marine character until 

 Upper Cretaceous time, those of the Lower Cretaceous lying buried from 

 observation far to the eastward. 



Floras in the marine deposits of this stage are scarce and unimportant 

 biologically, although they are of considerable stratigraphic importance 

 if they are of terrestrial origin, in furnishing data for correlation. Often 

 these fossils are impressions of seaweeds or similar indefinite objects. 



Switzerland 



From the marine beds in the cantons of Berne, Yaud, A^penzell in 



Switzerland, and Eapatz in Freiberg Heer ^ has described the following : 



Aulacophycus pedatus Heer 

 Bambusium neocomense Heer 

 Caulerpa Lehmanni Heer 

 Chondrites serpentinus Heer 

 Chondrites neocomensis Heer 

 Discophorites angustilobus Heer 

 Discophorites Fischeri Heer 

 Fucoides friburgensis Heer 

 Gyrophyllites Oosteri Heer 

 Gyrophyllites pentamerus Heer 

 Sphaerococcites meyrati Fischer-Ooster 

 Zamites (Dioonites) Eaufmanni Heer 



^ Heer, Fl. Foss. Helvetiae, vierte abth., 1877. 



