The Botany of Iceland - 01.12.1928, Side 114

438 JOHS. bove petersen: the aérial algæ of iceland
When I visited the same locality in 1914, I found similar condi-
tions. A small stream flows out by the meadow, the mouth of which
has become funnel-shaped owing to the strong tides, with an enormous
bed in proportion to its volume of water. On the sloping sides grew
V. sphœrospora, forming connected, somewhat tufted growths on the
muddy bottom. During high tide these growths will be ílooded with
salt water. (Fig. 1, p. 357). In the same way it grew in a small stream
cutting the littoral meadow, and in a depression with otherwise naked
clayey bottom, in both places under such conditions that it must be
flooded with salt water at high tide.
The species must be designated as a halophilous species, hardly
growing much above high water mark.
Vaucheria terrestris Lyngb. Heering 1907, p. 160.
N. W. Icel. 264.
I have only met with this species in one place, viz. on a road
near Isafjörður. As in Denmark (Boye Petersen 1915, p. 349), so also
in Iceland it seeins to be of rarer occurrence than V. hamata.
RHODOPHYCEÆ.
Rhodochorton islandicum Rosenv.
Kolderup Rosenvinge 1900, p. 61.
H. Jónsson 1911, p. 119.
This species I have mentioned on p. 363, and I have nothing to add.