Fossil Floras of the Arctic Regions. 221 



travelled from very distant localities. One has not with certainty 

 observed any marine petrifactions associated with the plants, but it 

 has not yet been clearly determined whether the Triassic beds with 

 fossil plants of Spitzbergen are of marine or of freshwater origin. 



The most ancient Jurassic sediments of Spitzbergen are marine, and 

 belong to the Sequanian stage. There was consequently a long 

 interruption in sedimentation after the formation of the Rhsetic beds. 1 

 The upper part of the Jurassic formation (Portlandian) furnishes 

 a series of plant-bearing sandstones, seams of coal, and beds of 

 undoubted freshwater origin, containing TJnio and Lioplax polaris. 

 The fossil plant-remains belong to two different floras, one, the more 

 ancient, being characterized by the presence of Ginkgo digitata, Brongn., 

 sp. ; the other, the more recent, by Elaiides curvifolia, Dkr., sp. 

 The two floras are associated with beds of coal, and one may here also 

 put forward the view that the plants originally flourished in the place 

 where they are now found. One of the coal-seams at Cape Bohernan 

 furnishes a great abundance of Podozamites and Pitgophi/llum ; some- 

 times the surface of the schists is as completely covered with the 

 leaves of Ginkgo digitata, as the soil beneath a living Ginkgo tree may 

 be in autumn. Since branches and seeds of the same plant are also- 

 associated, it is natural to suppose that a Ginkgo forest occurred not 

 far away from this spot. The same observation applies to Elatides 

 curvifolia of the more recent flora, which occurs locally in the fresh- 

 water beds containing TJnio and Lioplax. Floras of the same age and 

 composition are also known from King Karl's Land, the islands of 

 New Siberia, 2 from Northern Siberia, and Arctic Alaska. 



The Neocomian Series of King Karl's Land is overlain by sheets of 

 basalt, often amygdaloidal, and containing chalcedony and agates. 

 Fragments of silicified woods, large and small, also occur here, and 

 these, without doubt, owe their mineralization to the volcanic 

 phenomena. Some of these trunks are fairly large, and I have 

 myself measured one, which, although incomplete, was 70-80 cm. 

 in diameter, and showed 210 annular rings. Some of these remains 

 consist of the lower portion of the trunk and the primary ramifications 

 of the roots. 



The microscopic examination of these specimens, undertaken by 

 Dr. W. Gothan, 3 has shown that the annual rings of the fossil stems 

 from King Karl's Land were much more accentuated than those of 

 stems found in the corresponding beds of the European continent, 

 which indicates that the trees lived in a region where the difference 

 between the seasons was extremely pronounced. They cannot there- 

 fore have been transported from the south by marine currents, and as 

 the trunks found in the corresponding beds of Spitzbergen 4 show the 



1 A. G. Nathorst, " Beitrage zur Geologie der Baren Insel, Spitzbergens, und 

 des Konig Karl Landes " : Bull. Geol. Inst. Upsala, vol. x, 1910. 



2 Id., " Uber Trias und Jurapflanzen von der Insel Kotelny " : Mem. Akad. 

 Imp. Sci. St. Petersbourg, ser. VIII, vol. xxi, No. 2, 1907. 



3 W. Gothan, "Die fossilen Holzer von Konig KarlsLand": Kongl. Svenska 

 Vet. -Akad. Handl., vol. xlii, No. 10, 1907. 



4 Id., "Die fossilen Holzreste von Spitzbergen": Kongl. Svenska Vet.- 

 Akad. Handl., vol. xlv, No. 8, 1910. 



