XXXll INTRODUCTION. 



and in comparing this flora with those of other countries a 

 resemblance is pointed out between the Japanese plants and 

 some species described by Heer from Siberia and Spitzbergen. 



Nine years later Matajoro Yokoyama 1 contributed a paper on 

 the Jurassic plants of Kaga, Hida and Echizen, and adds a list 

 of species from these localities. At a later date 2 he gives a 

 much fuller account of this exceedingly interesting flora ; and 

 a detailed comparison is instituted with floras of other countries, 

 the Jurassic floras of Siberia, Spitzbergen, the Yorkshire coast, 

 Russia, China, India and Australia, also with the Wealden of 

 Europe and the infra-Liassic of Tongking. 



A reference is made by Lester Ward 3 in his " Geographical 

 Distribution of Fossil Plants" to Yokoyama's earlier paper, and 

 the suggestion offered that possibly these Japanese plants may 

 prove to be of Lower Cretaceous age, and that the reference by 

 Godfrey of the Kiushin leaf-beds to a Cretaceous horizon may 

 have been correct. 4 The evidence afforded by the ferns is certainly 

 in favour of Ward's suggestion. 



In 1890 Nathorst 5 made an important contribution to our 

 knowledge of Japanese pala3obotany. The plants from some of 

 the localities are compared principally to Wealden species, and 

 from other places there seems to be a mixture of Jurassic with 

 Wealden and TJrgonian species. 



Although the titles to the papers of Geyler and Yokoyama 

 lead us to expect floras of distinctly Jurassic facies, we shall 

 have occasion to point out in the description of certain English 

 Wealden species a striking similarity, if not specific identity, 

 between them and some of the Japanese plants. 



The following list includes the plants mentioned by Yokoyama 

 and Nathorst: 



1 Bull. Geol. Soc. Japan, pt. B, vol. i. No. 1, 1886. 



2 Journ. Coll. Sci. Japan, vol. iii. 1890, p. I. 



3 U.S. Geol. Surv. Ann. Kep. No. 8, p. 789. 



4 Quart. Journ. Geol. Soc. vol. xxxiv. 1878, p. 546. 



Denksch. k. Ak. Wiss. math.-nat. Cl. vol. Ivii. 1890, p. 43. 



