56 



KJELLMAN, THE ALG^ OF THE ARCTIC SEA. 



*Rhodochorton Rothii, 



Porphyra laciniata, 

 *Fucus vesiculosus, 



* » ceranoides, 

 » spiralis? 



* » evanescens, 



» miclonensis? 



*Alaria Pylaii? 



*A.garum Turneri, 

 Phyllaria dermatodea, 

 Laminaria saccharina? 



* » longicruris, 

 » digitata ? 



» stenophylla, 



*Chorda filum, 

 *Ralfsia deusta, 

 *Chordaria flagelliforrais, 

 *Elachista fucicola, 

 *Lithoderma fatiscens, 

 *Ilea fascia, 



*Scytosiphon lomentarius, 

 *Desinarestia aculeata, 

 *Dichloria viridis, 

 *Phloeospora tortilis, 

 *Dictyosiphon foeniculaceus, 

 *Chsetopteris plumosa, 

 *Ectocarpus confervoides, 

 *Pylaiella litoralis, 



Enteromorpha clathrata, 



» intestinalis, 



* » compressa, 



Ulva lactuca, 

 *iMonostroma fuscum. 

 *Spongomorpha arcta, 



Cladophora glaucescens? 

 *Rhizocloniuna ripariuin, 

 *Chaetomorpha melagonium, 



» tortuosa, 



*Urospora penicilliformis, 



Bryopsis plumosa. 



Of these 70 species, no less than 41, viz. those marked with an asterisk, accordingly 

 58^ per cent, are at present known with certainty from the arctic parts of the Polar 

 Sea, and amongst these 41 species there are several of the most commonly distributed 

 and most characteristic forms of that region of the Polar Sea which is rich in ice. As 

 moreover many of them, as has been shown above, are chiefly distributed northwards 

 at least in the Atlantic — there are no detailed statements to be had for the Pacific — 

 we are justified in placing their origin in a glacial sea and in assuming that they have 

 passed from there to the northern Atlantic and the northern part of the Pacific. The 

 percentage of arctic forms amongst those species which are reported common to the Arctic 

 Sea and the northern part of the Atlantic and of the Pacific, is in all probability larger than 

 what is indicated by the figures mentioned. For there is some reason to suppose that a 

 rather large number of species from the northern part of the Pacific, which have been 

 considered identical with forms from the Atlantic, will prove on closer examination to be 

 specifically distinct or wrongly determined. This is probably the case with those marked 

 with a sign of interrogation in the above list ^). Their number amounts to 16. If 

 these are deducted, the arctic forms would constitute about 75 % of the whole number 

 of species that the Arctic Sea has in common with the northern part of the Atlantic 

 and the northern Pacific. Of the 13 species then remaining, Porphyra laciniata, Entero- 

 morpha intestinalis auct., E. clathrata auct. and Ulva lactuca, which are however met 



>) In support of this supposition, I refer to the notices on these species which are given by J. G. Agakdh in 

 Spec. Alg., Epicr. and his treatises on the arctic marine Flora, by Rdprecht in Alg Ochot byPARLOW in 

 New Engl. Alg , by Harvej- in Xer. Am. and Alg. Vane, by Postels and Rhpeecht in 111. Alg 



