22 Art. 8.— A. Kryshtofovich : 



4. Eelations of the Cketaceous and Teetiaey 

 Floeas of Sakhalin. 



After establishing the general contents of the Cretaceous flora 

 in Sakhalin, we must confirm the Tertiary age of the flora of the 

 workable seams of Mgach and also of the coal mines of Alexand- 

 rofsk. This flora of the Mgach Coal mine (not of the seashore), 

 being now quite freed of the Cretaceous elements, shows a very 

 close similarity to the Tertiary floras of Japan, described by 

 Nathoest,^^ also to the true Tertiary floras of the Eussian Maritime 

 ProYinco. Consisting chiefly of Amentiflora? and containing very 

 few ferns, this flora is quite different from that of the Cretaceous. 

 An object of considerable interest is the occurrence of Salvinia sp. 

 in Mgach. The relation between the Cretaceous and Lower Ter- 

 tiary floras of Sakhalin seems to be a distant one. The proper 

 Gyliakian flora has nothing in common with the Tertiary, 

 probably with the only exception of Populus arctica. The study of 

 the relation of the Orokkian with the Lower Tertiary in Sakhalin 

 is yet a task for future studies, and nothing on this question can 

 be expressed at present. The Lower Tertiary is anyhow closely 

 allied to the flora of the Naibuchi coal-field in Japanese Sakhalin 

 and that of Hokkaido, as well as to the Japanese " Pre-pliocene " 

 floras of Naïhoest. 



5. Eelations between the Ceetaceous Floeas of 

 Sakhalin and Japan. 

 The Cretaceous floras of Sakhalin stand quite solitary in 

 position in the Far East. An unpublished paper of Mr. H. 

 Tanakadate treats of some fossils, from Makai and Onnenai, both 

 in Japanese Sakhalin, which I regard as probably Orokkian. Be- 

 sides some Cretaceous plant-leaves collected from Hokkaido by 



1) Nathoest (1888). 



