340 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 



the trunks found in the corresponding beds of Spitsbergen * show 

 the same peculiarity, it is quite safe to conclude that we are here 

 concerned with large trees, which have actually flourished in these 

 latitudes, and which have not been transported from more southern 

 regions. 2 



The Cretaceous system, as we know it, is represented in western 

 Greenland, between the parallels of 69° and 71°, by an important 

 series of beds containing fossil plants belonging to the Urgonian, 

 Cenomanian, and Senonian, the two first mentioned containing coal 

 seams. I have been able to show, as the result of the studies which 

 I made in Greenland in 1883, that beds, full of roots, underlie those 

 containing fossil plants at Unartoarsuk, as well as at Igdlokanguak. 

 Without doubt the Urgonian flora, like the Cenomanian flora, is a 

 relic of vegetation which once flourished in the same regions where 

 we now find the fossils. But, on the contrary, the Senonian flora, or 

 flora of Patoot, is in part contained in marine beds, containing 

 Inoceramus, etc., and thus it may have been transported from some 

 distance. The Urgonian flora, or flora of Kome, is composed of 

 ferns, cycadophytes, and conifers, while the Cenomanian or Atane 

 flora, in addition to arborescent ferns (Dicksonia) and cycadophytes 

 (Pseudocycas) , 3 is particularly rich in the leaves of Dicotyledonous 

 trees, among which are found those of planes, tulip trees, and bread 

 fruits, the last mentioned closely resembling those of the bread-fruit 

 tree (Artocarpus incisaY of the islands of the southern seas. 



In the limited space at my disposal I have had to be content with 

 a brief summary of the strata containing fossil floras of Palaeozoic and 

 Mesozoic age. But from what has been said it is clear that we have 

 every reason to regard the flora of the Devonian, Culm, Jurassic, and 

 Cretaceous of the Arctic regions as being composed of plants which 

 flourished in these very regions. There are no proofs that the 

 Triassic flora has been transported from more southern regions by 

 marine currents, but there is, however, some uncertainty on this 

 point. 



1 Id., "Die fossilen Holzreste von Spitzbergen": Kongl. Svenska Vet.-Akad. Hand!., vol. 45, No. 8; 

 Stockholm, 1910. 



5 It may be mentioned here that a silicified Dadoxylon, from the Carboniferous deposits of Spitsbergen, 

 described by Dr. Gothan (loc. cit.) does not show any annual rings at all, as is precisely the case with the 

 corresponding Palaeozoic stems of Europe. As has been pointed out to me by Dr. Th. Halle, this is a 

 most curious circumstance, since the darkness during the long winter night in these regions — provided 

 that the position of the North Pole were the same as now — ought to have caused an interruption of growth, 

 even if the climate was a warm and genial one. As the specimen, however, was not found in situ, it is 

 possible that it originates from some marine deposit into which the wood had been brought by ocean cur- 

 rents from more southern latitudes. But a Dadoxylon from the Triassic of Spitsbergen also shows only 

 slight indications of annual rings (Gothan, loc. cit.). 



3 A. G. Nathorst, " Palaobotanische Mitteilungen, 1. Pseudocycas, eine neue Cycadophy tengattung aus 

 den Cenomanen Kreideablagerungen Gronlands": Kongl. Svenska Vet.-Akad. Handl., vol. 62, No. 5; 

 Stockholm, 1907. 



« Id., "tiber die Resteeines Brotfruchtbaumes, Artocarpus Dickson! , n. sp., aus den Cenomanen Kreide- 

 ablagerungen Gronlands": Kongl. Svenska Vet.-Akad. Hand!., vol. 24, No. 1; Stockholm, 1890. 



