340 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
the trunks found in the corresponding beds of Spitsbergen 1 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.? 
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),* 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 incisa)* 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 Paleozoic and 
€SOZO1 . But fr aid it is clear that we have 
Mesozoic age. But from what has been said it is clear that we hav 
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. 
11d., “Die fossilen Holzreste von Spitzbergen”: Kongl. Svenska Vet.-Akad. Handi., vol. 45, No. 8; 
Stockholm, 1910. 
2It may be mentioned here that a silicified Dadorylon, 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 Palzeozoic stems of Europe. As has been pointed out to me by Dr. Th. Halle, this isa 
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 wat a warm and genial one. As the specimen, however, was not found in situ, itis 
possible that it originates from some marine deposit into which the wood had been brought by ocean cur- 
rents from more southern latitudes. Buta 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 Cycadophytengattung aus 
den Cenomanen Kreideablagerungen Groénlands”: Kongl. Svenska Vet.-Akad. Handl., vol. 62, No. 5; 
Stockholm, 1907. 
41d., ‘Uber die Reste eines Brotfruchtbaumes,:A rtocarpus Dicksoni, n. sp., aus den Cenomanen Kreide- 
ablagerungen Grénlands’’: Kongl. Svenska Vet.-Akad. Handl., vol. 24, No. 1; Stockholm, 1890, 
