FOSSIL FLORAS OF ARCTIC REGIONS—NATHORST. 343 
show that we have here to deal with fresh-water deposits. M.Ostrup’s ! 
microscopic cxamination of the diatoms, found in the same beds as 
the fossil plants, confirms this conclusion, for they are fresh-water 
species. 
Among the beds furnishing Tertiary plants, so abundant in Green- 
land, I will only mention those of Harén (Hare Island), near 
Waigattet. cre the plants occur either in a true basaltic tuff, or 
in an altered tufa or a sediment formed from it, which is overlain 
with basalts. 
The investigation of two beds, which I made in 1883, has proved 
that they can not be other than formations laid down above sea level. 
In one of these deposits the fossil flora consisted almost exclusively of 
leaves of the maple (Acer), crowded like those which cover the ground 
in autumn, and among these leaves large samaras, like those of 
A. otopteryx Gp., occur. In another bed the tuff was formed of 
cinders and small lapilli, and the way in which the vegetable 
fragments were inbedded leads one to suppose that the branches, 
leaves, and fruits of the trees were broken off by a shower of cinders 
and lapilli. A medley of silicified branches of different sizes occurs, 
and among them are the cones of the spruce, the nuts of the walnut 
(Juglans), and the hickory (Carya), with the leaves of Ginkgo, ete. 
In the finer tufts we likewise find the leaves of the walnut, the leaves 
and fruits of an ash (Frazinus macrophylla Hr.), and the leaves of 
species common in the Tertiary flora of Greenland, such as the plane, 
oak, chestnut, beech, etc. 
The presence of the leaves of Potamogeton, associated with a fresh- 
water mussel (Unio), indicates that the deposits were of fresh-water 
origin. Some of the branches of the trees are silicified and exhibit, 
under the microscope, an extremely well-preserved structure. Dr. 
J. Schuster, who has undertaken a preliminary examination of these 
remains, concludes that they all belong to one species, which was 
probably either an arborescent member of the leruminosee or of the 
rosacee. It is clear that we have here to deal with fragments of 
vegetation broken off by a shower of ashes and entombed in them, 
though some fragments may have been transported into a fresh-water 
basin containing mussels and aquatic plants. 
The Tertiary plants discovered by the Norwegian expedition to 
Ellesmere Land deserve special mention on account of their state of 
preservation. They consist almost entirely of branches of Seqgyoia — 
Langsdorfii, contained in a bituminous laminated clay, from which 
I have been able to remove them by a process of washing, with 
the result that they are now isolated like dried specimens in a 
herbarium. ° 
1 E. Ostrup, “Diatoméerne i nogle islandske Surtarbrandlag,” pt. 1: Meddel. fra Dansk Geol. Forening, 
No. 3; Copenhagen, 1896. Pt. 2, ibid., No. 6, 1900. 
