Maryland Geological Survey 115 



Rhynchogoniopsis neocomiensis Neumann 



Weichselia reticulata (S. & W.) Ward 

 Zamiostrobus crassus (L. & H.) Goeppert 

 Zamiostrobus aff. index Saporta 



Japan 



The major divisions of the Mesozoic are all represented in Japan, the 

 Cretaceous to a greater extent than the Triassic or Jurassic. It is de- 

 veloped over large areas in northern Japan and also in southern Japan/ 

 Eocks classed as Bathonian by the Japanese paleontologists furnish an 

 extensive flora/ several species of which continue into the Lower Cre- 

 taceous of that country. 



The JSTeocomian plants which were first studied by Nathorst ^ occur 

 in the Ryoseld series which is widely distributed and contains several 

 fossiliferous horizons, so that unlike most Neocomian plant deposits 

 those of Japan are intimately associated with beds containing marine 

 invertebrates, such as Trigonia, Avicula, Belemnites, Cyrena, and various 

 Stephanoceratidse. The final elaboration of this flora we owe to Professor 

 Yokoyama * who compares it with the European Wealden and the Ameri- 

 can Potomac, regarding it as representing the whole of the Neocomian. 

 The total number of species recorded are the following : 



Adiantites yuasensis Yokoyama 



CladopJilebis Broioniana (Dunker) Seward 



Cladophlebis Nathoisti Yokoyama 



CladopJilebis Ungeri (Dunker) Ward (P. Geyleriana Nathorst) 



Cyparissidium ? japonicum Yokoyama 



Dicksonia tosana Yokoyama 



Dicksoniopteris Naumanni Nathorst 



Dioonites Buchianus (Ettings.) Born. 



Dioonites Buchianus angustifolius Fontaine 



Qlossozamites parvifolius Yokoyama 



Lycopodites sp., Nathorst 



^ Outlines of Geol. of Japan, 1902, compiled by Imp. Geol. Surv., pp. 48-74. 



^ Yokoyama, Jurassic Plants from Kaga, Hida, and Echizen, Journ. Coll. Sci. 

 Imp. Univ., vol. iii, 1889. 



^Nathorst, Beitr. Mes. Fl. Japans. Denks. k. Akad. Wiss., Wien, Band Ivii, 

 1890. 



* Yokoyama, Mesozoic Plants from Kozuke, Kii, Awa, and Tosa, Jour. Coll. 

 Sci., Imp. Univ., vol. vii, 1895. 



