26 Art. 8.— A. Kryshtofovich : 



Ainuan, which correspond well with the plant-bearing strata of 

 Greenland and America. 



5. The fixed composition of these floras in the definite 

 horizons of the Upper-Cretaceons shows the development of vege- 

 tation in Eastern Asia, and furnishes material for the discussion 

 on the origin of younger floras. 



6. The present study will lead to the revision of Siberian 

 Cretaceous floras, until now mistaken for Tertiary. 



7. There is a probability of close affinity of some plant- 

 bearing horizons in Sakhalin and Hokkaido. 



8. The Cretaceous coals of Kussian Sakhalin, so far known, 

 contain more ashes than its Tertiary coals. 



The full revision of plant-fossils in Hokkaido and Sakhalin, in 

 connection with the simultaneous occurrence of different floras and 

 faunas, will fix a firm base for their comparison with the other 

 floras of Eastern Asia, and consequently the proper determination 

 of their ages. The work will, moreover, afford important materials 

 for discussion on the origin and migration of the Dicotyledonous 

 Flora, probably radially from the Arctic region, as asserted by 

 Asa Geay'^ and others, and recently by Berry.'^ 



Finally, I feel it an agreeable duty to say that the successful 

 elaboration of the specimens for the present work has been realized 

 solely by the very kind support of the Geological Institute of the 

 Imperial Tokyo University and the Töhoku University at Sendai, 

 and of the Imperial Geological Survey of Japan. I take this 

 opportunity to express my cordial thanks to the representatives of 

 all these Institutions, to Professors M. Yokoyama, K. Jimbö, and 

 H. Yx\.BE, and Director K. Inoue. 



1) Asa Geay (1859) ; Sapokta (1872) p. 328 etc. ; Sapoeta et Marion (1876), p. 40 etc. 

 2) Beert (1911), p.50, 51. 



