KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. iD 
with their companions, might be regarded as a sort of litoral formation in course of 
development, precurser of the present formation of Fucacew on the coast of Norway. 
It might be named a prelitoral formation. 
The formation of Laminariacee is, as mentioned before, the best marked and most 
widely distributed vegetation in the whole Arctic Sea, covering also the largest area. 
Its composition varies in different parts both with regard to the species predominating 
and the species forming the under-vegetation in these arctic woods of algw. But al- 
though the Laminariacew comprise a considerable number of species, agreater one, indeed, 
than has hitherto been supposed, they are all referable to one and the same geueral 
type, and on that account the formation constituted by them makes everywhere, on 
the whole, the same impression. As the variations in the composition of the formation 
of Laminariacee afford the best characteristics for distinguishing and defining different 
narrower regions of the arctic marine Flora, they will be set forth in detail, in the 
description of the regions alluded to. The formation of Laminariacew is most strougly 
developed on a bottom of solid rock or large stones. In the Norwegian Polar Sea and 
in Baffin Bay on the west coast of Greenland its upper margin coincides with high-tide 
mark, and from there it descends in all its richness to the depth of 2—5 fathoms. 
Deeper down it diminishes in number of individuals, but often increases in luxuriancy. 
Within the rest of the Arctic Sea, it generally keeps to the lower parts of the sublitoral 
region, in about 8—10 fathoms water. On the coast of Norway, in such places where 
the bottom is looser, consisting of sand, gravel, and smaller stones, within the upper 
portion of the sublitoral zone, the formation of Laminariacew assumes an aspect very 
different from the typical one. The common species of Laminaria and Alaria draw 
back, diminishing in number and luxuriancy, and instead of these another Laminariea, 
Phyllaria dermatodea, increases so as to form the main mass of the vegetation, in con- 
junction with Chorda filum, Chordaria flagelliformis, Dictyosiphon hippuroides, Monostroma 
fuscum, Spongomorpha arcta, Diploderma amplissimum a. o. 
The formation of Corallinaceew is poor in species and differently composed in diffe- 
rent parts of the Arctic Sea. On the coast of Norway Lithothamnion soriferum pre- 
dominates. Fastened to this, there are found in small numbers Chantransia efjlove- 
scens, Delesseria sinuosa, Khodophyllis dichotoma, Kallyimenia septemtrionalis, Antitham- 
nion Pylaisei and boreale, Derbesia marina, and some few others. On the coasts of 
Spitzbergen and the west coast of Novaya Zemlya Lithothamnion glaciale is the prin- 
cipal species. Together with this, there are found Ptilota pectinata in great numbers 
and Delesseria sinuosa, Rhodophyllis dichotoma, Euthova cristata and Antithamnion boreal: 
less abundant. *) The formation of Corullinacew on the west coast of Greenland in Baflin 
Bay is probably constituted in the same way. In the western part of the Kara Sea, 
where it is characterized by Lithophyllwm arcticum, it was also found to be uncommonly 
rich in Huthora cristata. One or two Laminariew and a small number of Antithamnion 
boreale were met with besides. *) 
') Cp. Ksetimayx, Algeny. Murm. Meer., p. 66. 
2) Cp. Kseniman, Kariska hafvets Algy. pp. 10—11. 
