KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 20. N:0 5. g 
With regard also to the distribution of the vegetation on the several bottom -zones 
different parts of the Arctic Sea differ essentially. In the Norwegian Polar Sea the 
litoral zone is overgrown with a rich, luxuriant vegetation of varying composition. 
More than half of the species known from this sea occur on this region of the bottom, 
either exclusively or at least sometimes. Some of them, for instance Rhodomela lyco- 
podioides, Gigartina mamillosa, Chondrus crispus, do not certainly attain here the same 
luxuriant development as farther southwards on the coast of Norway, but the great 
majority are as flourishing here and form as dense masses as on the coasts of the 
North Atlantic. On the west coast of southern Greenland there is also to be found a 
litoral vegetation very rich in individuals, although it is more monotonous. I have been 
informed by Professor Tu. Fries that the litoral zone is clothed with Fucacew, and that these 
constitute the peculiar character of the litoral vegetation. That however several other 
species occur, beside these, is shown by the collections made here, containing several 
purely litoral algw. With regard to several of these, J. Vani has, besides, expressly 
noted on the labels, that they were found growing within the litoral zone. Of such 
species I mention here: Rhodomela lycopodioides, Polysiphonia urceolata, Halosaccion 
ramentaceum, Llea fascia, Pylaiella litoralis, Enteromorpha intestinalis, E. compressa and 
E. micrococea, Monostroma blyttii, Diplonema percursum, Spongomorpha arcta, Cladophora 
rupestris, Rhizoclonium rigidum and Kh. riparium, Chetomorpha Wormskioldii, Urospora 
penicilliformis, Rivularia atra. In the by far greater part of the Arctic Sea the litoral 
zone possesses no vegetation at all or an exceedingly meagre one. On the coasts of 
Spitzbergen I have found the following species in the litoral zone: Rhodochorton Rothii 
and Rh. intermedium, Fucus evanescens f. bursigera and nana, Chetopteris plumosa, Pylaiella 
litoralis, Chetophora maritima, Enteromorpha compressa, Spongomorpha arcta, Rhizoclonium 
riparium, Ulothrix discifera, Urospora penicilliformis, Codiolum Nordenskiildianum, Calothrix 
scopulorum. This number of species is certainly pretty considerable, but it should be 
observed, that the majority are either generally very rare or at least very rare in the 
litoral zone. Fucus evanescens, commonly diffused in its larger forms on the coasts of 
Spitzbergen, seldom ascends into the litoral zone. In the form bursigera it has been 
found here in two places, in the form nana in one, always in plots of small extent. 
Chetopteris plumosa, one of the commonest alge of Spitzbergen, I have found as litoral 
only once and then only a few specimens. Pylaiella litoralis and Spongomorpha arcta, 
both of them rather common in the sublitoral zone, are very rare in the litoral. The 
two Rhodochorta, Ulothrix discifera and Codiolum Nordenskiéldianum have been met with, 
each of them, only in one place within the litoral zone of Spitzbergen. Only Entero- 
morpha compressa, Rhizoclonium riparium, Urospora penicilliformis and Calothria scopulo- 
rum occur more commonly or in somewhat greater nuinbers on the uppermost part of 
the bottom at Spitzbergen. In the by far greatest part of this zone there is no vege- 
tation at all. The same poverty is exhibited by the litoral zone in the eastern part 
of the Murman Sea; in the western part of it as well as in the White Sea it probably 
stands in the middle between the richness of the Norwegian Polar Sea and the poverty 
of the Greenland Sea‘). In my account of the vegetation on the west coast of Novaya 
') Cp. Crenxowsky, Bericht. 
. 
K. Vet. Akad. Hand]. Band. 20. N:o 5. 2 
