"Miocene Flora" of Sakhalin. 507 



Gleichenia rigida Heer 



G. zippei (Corda) Heer 



Gleichenia sp. 



Asplenium dicksonianum Heer 



Populus cf. potomacensis Ward 



The general composition of these floras and the 

 presence in the youngest horizon of an Ammonite fauna 

 compels me to regard the whole flora as undoubtedly Cre- 

 taceous. However, its different horizons show some 

 peculiar features. Thus the flora of the uppermost 

 series, the Orokkian, shows a younger aspect, and might 

 very readily be mistaken for Tertiary on account of con- 

 taining many species common in the so-called Arctic 

 Tertiary floras of Greenland, Spitzbergen, etc., but 

 scarcely anything is common to the latter and the true 

 Tertiary flora of Sakhalin. The undoubted Cretaceous 

 age of the Sakhalin floras listed above and the presence 

 in them of elements characteristic of the "Arcto-Ter- 

 tiary" flora leads me to suggest a revision of the age of 

 the latter, which may be really even older than the similar 

 floras in Sakhalin, on account of their more northern 

 position, if the migration of floras was really from the 

 north. 



The characteristic form of Orokkian, Populus arctica, 

 has not yet been found in the Dui series (though it occurs 

 in the lower Tertiary flora of Onnenai in Japanese 

 Sakhalin) but it is abundantly represented in the Gylia- 

 kian together with some typical Cretaceous plants. I 

 regard this horizon as an equivalent of the Patoot of 

 Greenland, and being not very different in age from the 

 prebasaltic deposits of Atanekerdluk, the latter undoubt- 

 edly Cretaceous and not Tertiary as it has been hitherto 

 considered. Thus the age of this Series may be taken as 

 Senonian and possibly partly Turonian. 



The flora of the Gyliakian is very rich in ferns resem- 

 bling those of the Atane and Dakota floras and partly 

 those of the Patapsco formation. Several cycads also 

 suggest those of the Atane beds of Greenland and the 

 Cenomanian of other countries. The Conifers and the 

 Angiosperms are also very tvpical of the Cretaceous, 

 especially of the Raritan and Dakota, e. g., Protophyllo- 

 cladus. Bammara, Bauhinia cretacea; Aralia polevoi is 

 very similar to Aralia ephyllum magnifolium of the 

 Patapsco; Celastropliyllum yokoyamai closely resem- 



