6 
T. G. HALLE, ■ 
(Schwed. Südpolar-Exp. 
In the following pages the different members of the Hope Bay flora, and the 
single plant from Snow Hill Island, will be described. No attempt has been made 
to give full lists of synonyms: such will be found in the larger works quoted, espe- 
cially in those by Seward. 
Description of the Species. 
A. Jurassic plants from Hope Bay. 
Equisetales. 
Genus Equisetites Sternberg. 
Equisetites approximatus Nath, in sched. n. sp. 
PI. I, figs. 6 — 14; lext-fig. I. 
The Equisetales are represented in the Hope Bay flora only by one form, of 
which a number of specimens have been found. It is treated here as a new species 
of Equisetites^ recognized as such alread}^ by Prof. Nathorst, who named it E. 
approximatus. 
Stem articulate, up to 2.5 — 3 cm. broad on the impression. Internodes short, 
up to 2.5 cm. long but generally less. Leaf-sheaths closely applied, consisting of 
T5 — 35 segments. Free parts of the teeth about 5 mm. long, acute, consisting of a 
thicker, triangular, pointed median portion, which is the continuation of the inter- 
commissural segments of the sheath, and thinner borders forming the upward conti- 
nuation of the tissue of the commissural furrows. 
Although this species comes fairly near to some others of Jurassic age, it does 
not seem possible to identify it with any one of them. The thickness of the stem 
varies very much and so does the distance between the nodes. The short length 
of the internodes, however, is a characteristic feature; only seldom are they as long 
as in the specimen shown in pi. i, fig. 8, but generally much shorter (figs. 6 and 9). 
It is not ])ossible to give an exact measure of the length of the coherent parts of 
the sheaths, because it is mostly impossible to locate the true position of the nodes, 
and the commissural furrows continue for some varying distance down on the next 
lower internode. Only rarely, however, are the commissural furrows as long compara- 
tively as in the stem in fig. 9, pi. i. In that specimen they nearly reach the next 
lower node, and a careful examination shows that the segments of two successive 
sheaths more or less regularly alternate with each other. The breadth of the seg- 
ments is generally about 1.5— 2 mm. at the lower ends of the commissural furrows; 
at the base of the free teeth the breadth of the commissural furrows is about equal 
