50 KJELLIIAN, THE ALGvE OF THE ARCTIC SEA. 



Laminaria atrofulva, Monostroraa leptodermum, 



» nigripes, Rhizocloniutn pachydermuin, 



Scytosiphon attenuatus, Ulothrix discifera, 



Phloeospora pumila, Chgetoraorpha Wormskioldii, 



Dictyosiphori corymbosus, Characium marinuin, 



» hispidus, Chlorochytrium inclusum, 



Chaetophora maritima, Rivularia microscopica. 



These species belong to 15 different families and 22 different genera. 



This strong endemisrn points to the purely arctic marine Flora being, contrary to 

 the arctic phanerogamous Flora, no immigrated Flora, but one that possesses its centre 

 of development in the Arctic Sea itself properly so called. Other circumstances lead 

 cogently to the same conclusion, indicating at the same time that the present purely 

 glacial marine Flora must have been formerly more widely spread towards the south 

 than it is now. This results, I think, from a comparison of the Flora of the Arctic 

 Sea with that of the northern Atlantic and the northern Pacific. 



The Arctic Sea, taken in a wide sense, possesses, as is shown by table 1, a con- 

 siderable number of species in common with the Northern Atlantic. 



These species amount to 184 (185). By far the greatest part are met with on 

 the Atlantic coast of Europe, only 11 are exclusively American. 



Amongst these, the following four are not known south of New-Foundland: 



Delesseria Montagnei, 

 Fucus miclonensis, 

 Laminaria Agardhii. 

 Phyllaria lorea. 

 Besides, I think it doubtful whether that plant from New-Foundland which has 

 been called Laminaria caperata is in reality identical with the Laminaria Agardhii of 

 the Arctic Sea. If this is not the case, Laminaria Agardhii is to be reckoned amongst 

 the endemic species of the Arctic Sea. The other 7 species: 



Ptilota pectinata, 

 Antithamnion Pylaisfei, 

 Fucus edentatus, 



» evanescens. 

 Laminaria longicruris, 

 Agarum Turneri, 

 Phyllaria dermatodea 



either are not known south of Cape Cod or at least have their proper area of distri- 

 bution north of this promontory ') and grow there most abundant and most richly 

 developed. It is known already by the researches of Harvey, fully confirmed by later 

 observations, that this protnontory on the east coast of America forms the boundary 

 between a more s outhern Flora and one expressly named arctic by American algologists^. 



') Cp. Farlow, New Engl. Alg. 

 -) Farlow, 1. c. p. 4. 



