KONGL. SV. VET. AKADEMIENS HANDLINGAR. 3AND. 20. N:0 5. 
Monostroma fuscum, Rhizoclonium pachydermum, 
» Blyttii, Cheetomorpha Wormskioldil, 
Diplonema percursum, » melagonium, 
Spongomorpha arcta, Urospora_ penicilliformis, 
Cladophora rupestris, Rivularia hemisphwrica. 
The character of the vegetation is chiefly marked in the province of Spitzbergen by: 
Alaria grandifolia, Laminaria digitata, 
» membranacea, » nigripes, 
Laminaria Agardhi, » solidungula: 
in the Siberian province by: 
Alaria dolichorhachis, Laminaria solidungula, 
» elliptica, » cuneifolia ; 
» ovata, 
in the American province by: 
Fucus vesiculosus, Laminaria atrofulva, 
Agarum Turner, » cunetfolia, 
Laminaria longicruris, Alaria spec.? (membranacea?) 
This difference of the vegetation of Laminariacew within the different provinces 
ean hardly be explained otherwise than by the supposition that secondary centres of 
development have been formed within the great arctic centre. Especially in that part 
of the Arctic Sea denominated the American province, the development of the Flora 
seems to have taken a direction independent of the others in certain respects. This 
is, besides, indicated by several other peculiarities of its vegetation, as the occurrence 
of such species as Kallymenia Pennyi, Antithamnion americanum, Rhodochorton spinulosum, 
and Chetomorpha Wormskioldii, but, above all, by the species of Delesseria of which 
no less than three belong exclusively to this province. One of these, D. corymbosa, 
is nearly related to D. Beri, pretty common in the province of Spitzbergen, and is 
perhaps to be considered as having branched off from this; another, D. JMontagnei, is 
most closely allied to and only slightly different from D. alata of the Atlantic, whose 
mother form it may possibly be; and the third, D. rostrata, resembles in habit most 
nearly Delesseria Berit, but in anatomical structure agrees more closely with D. alata 
or D. Montagnei, from the latter of which it may be thought to have issued. 
The general conclusion to which my investigation of the Flora of the Arctic Sea, 
taken in a wide sense, has led me, may be briefly stated thus: the arctic part of the Ocean 
comprises two separate regions differing with regard to their history of development, 
one situate on the north coast of Norway and closely connected with the Atlantic, the 
other arctic, comprehending the rest of the Arctic Sea; in different parts of the arctic 
region the development of the Flora has been in a certain degree independent, which 
is especially indicated by the distribution of the Laminariaceew; on this account, the 
arctic region may be devided into three provinces: that of Spitzbergen, the Siberian, 
and the American. 
