KONGL. SV. VET- AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 



4y 



have only lately been distinguished as separate species, and it is thus certainly possible 

 that some one or other of them, attention being now drawn to it, may prove to go 

 southward of the limit established for the Arctic See. But on the other hand, the 

 great majority consists of species so well marked by size and specific characters, that 

 it seems rather improbable, if they did occur farther to the south, that they would 

 have escaped observation on the coasts comparatively so accurately and long investigated 

 of the northern Atlantic, where in such a case most of them would be expected to 

 grow. About one third of them belong exclusively to those parts of the Arctic Sea 

 which are not filled with ice: the Norwegian Polar Sea, the western Murman and the 

 White Seas, namely: 



Lithothamnion soriferum, 

 » alcicorne, 



» intermedium, 



Polysiphonia Schubelerii, 



Halosaccion saccatum, 



Diploderma amplissimum, 



Lithoderma lignicola, 



Ectocarpus Lebelii, 



Pylaiella nana, 



Gleothamnion palmelloides, 



Monostroma undulatum, 



cylindraceum, 

 saccodeum. 



» arcticum, 



» crispatum, 



Ulothrix Sphacelarise, 



Chaetomorpha septemtrionalis, 



Chlorangium marinum, 



Gleocapsa spec. 



Chsetophora pellicula. 



Accordingly 21 species, representing 11 families and 14 genera. The other 42 species 

 occur all of them in the Arctic Sea proper. Only 11 or 10 of these have been as yet 

 met Avith also in the Norwegian Polar Sea, in the western Murman Sea, and in the 

 White Sea. These are: 



Lithothamnion glaciale, Sphacelaria arctica, 



» flavescens, Pylaiella varia, 



Kallymenia septemtrionalis, Ulva crassa, 



Porphyra abyssicola, Monostroma lubricum, 



Alaria membranacea, Codiolum Nordenskioldianum. 



» grandifolia? 



Thus there remain no less than 31 or 32 species that are endemic in the Arctic 

 Sea proper, namely: 



Lithothamnion foecundum, 

 » compactum, 



Lithophyllum arcticum, 

 Delesseria rostrata, 



» corymbosa, 



Haemescharia polygyna, 

 Kallymenia Pennyi, 

 » rosacea, 



Phyllophora interrupta, 



K. Vet. Akad. Handl. Bd 20. N:o 6. 



Rhodochorton spinulosum, 

 » intermedium, 



» spetsbergense, 



Diploderma miniatum, 

 Scaphospora arctica, 

 Alaria grandifolia? 

 » dolichorhachis, 

 » elliptica, 

 » oblonga, 



