224 Notices of Memoirs — Professor A. G. Nathorst — 



latter plant, in which the tissues have "been so completely mineralized 

 that one can study the microscopic structure as minutely as in the 

 living Osmunda. One sees in the carbonaceous petrified layers 

 rootlets and spores of ferns, as- well as fragments of branches, etc. 

 This might justly he called a mineralized peat. Among the Dicoty- 

 ledonous trees, the leaves of which occur in great quantity, one finds 

 leaves of all dimensions belonging to the more common species. 

 I have examples, among others, of the leaves of Vlmiphyllum 

 asperrimum, Nath., varying from 1-17 cm. in length. All the 

 observations indicate that we have here a deposit formed by the delta 

 of a stream, passing through a marsh, on which grew trees requiring 

 humidity, while the remains of other plants which lived at some 

 distance away have been transported, either by the wind or by water, 

 and become mingled with those of the marsh. 



The beds of this horizon, discovered at Cape Lyell, are remarkable 

 for the enormous quantity of leafy branches of Sequoia Langsdorfii, 

 leaves of Grewia crenata, Hr., and of Acer arcticum, Hr., the fruits of 

 the last mentioned also occurring. A bed fnll of rootlets was also 

 met with, showing that the plants flourished on the spot where they 

 are now found. Among the marsh plants an Alisma occurs. . Among 

 the Dicotyledonous trees of this horizon are Poplars (Populus), Willows 

 (Salix), Alders (Alnus), Birches (Betula), Hornbeams (Carpinus), 

 Hazels (Corylus), Beeches (Faff us), Oaks (Quercus), Elms (Ulmus), 

 Planes (Platanus), Magnolias (Magnolia), Limes (Tilea), and Maples 

 (Acer), etc. We can thus show that during the Tertiary period 

 all these plants have flourished at 78° or 79° of latitude. In 

 Grinnell Land we find, even at nearly 82°, the Swamp Cypresses, the 

 Spruces, Pines, Pirs, Poplars, Birches, Elms, Limes, etc. 



In Iceland the Tertiary flora may be studied in the volcanic tuffs or 

 in the alluvium formed from them, and at Brjamslaekur, for instance, 

 in a deposit which may be compared with a laminated peat. Thus, 

 as Heer had suggested, and Thoroddsen has proved, we here meet with 

 formations laid down above sea-level, which are overlain by thick 

 basaltic beds. A glance at the specimens from Brjarnslaekur_serves to 

 show that we have here to deal with freshwater deposits. M. Ostrup's 1 

 microscopic examination of the Diatoms, found in the same beds as 

 the fossil plants, confirms this conclusion, for they are freshwater 

 species. 



Among the beds furnishing Tertiary plants, so abundant in Greenland, 

 I will only mention that at Haron, near Waigattet. Here the plants 

 occur either in a true basaltic tuff or in an altered tufa or a sediment 

 formed from it, and overlain with basalts. 



The investigation of two beds, which I made in 1883, has proved 

 that they cannot 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 



1 E. Ostrup, " Diatomeerne i nogle islandske Surtarbrandlag," pt. i: 

 Meddel. fra Dansk Geol. Forening, No. 3 ; Copenhagen, 1896. Pt. ii, ibid., 

 No. 6, 1900. 



