KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 305 



Exsicc. Syn. Cladophora arcta Kjellm. Vinteralgv. p. 65; Spetsb. Thall. 2, p. 55; Algenv. Murm. Meer. p. 54. 

 » » Kleen, Nordl. Alg. p. 45. 



» » Wittr. in Heugl. Eeise, p. 284. 



» polaris Harv. New Alg. p. .334. 



Conferva arcta J. G. Ag. Spetsb. Alg. Progr. p. 2; Bidr. p. 11; Till. p. .38. 

 » centralis .J. G. Ag. Grönl. Alg. p. 110. 



» glomerata marina J. G. Ag. Spetsb. Alg. Bidr. p. 11. 



» n (i. » Lindbl. Bot Not. p. 158. 



Remark on the determination of this species. This species is taken here in the wide 

 sense given it by Areschoug 1. c. It then includes several forms that may well ap- 

 pear rather different and have indeed been described as separata species. Thus Con- 

 ferva Arcta Harv. C. centralis Lyngb. belongs to it and so do perhaps all Cladophorce 

 of the group called Coinosw by Kutzing (in Spec. Alg.), but at least Cl. strida, Cl. co- 

 rnosa, Cl. vaucherif armis, and Cl. sa.cculifera. However these are all, according to Are- 

 schoug and Haevey, to be regarded as one and the same- species at different stages 

 of development and in different forms. I am obliged at present to subordinate my 

 own opinion to that of these two great authorities. 



Hahitat. This species is litoral in the Norwegian Polar Sea, sublitoral, as far as 

 I know, in the other parts of the Polar Sea, growing in 2 — 10 fathoms water, being 

 in both cases sometimes epiphytic on other alg£e, but usually attached to stones, poles 

 a. s. o. It flourishes on exposed as well as sheltered coasts, both in salt and somewhat 

 brackish watei". On the north coast of Norway it is generally gregarious in great 

 numbers, but in the Arctic Sea proper I have never found but isolated individuals. 

 On one occasion I met with a form most nearly coinciding with Conferva centralis 

 lying loose on the bottom within the sublitoral zone. The pi-esent alga occurs all the year 

 round, even in winter, on the north coast of Spitzbergen. I never found any luxuri- 

 ant specimens of it during the last-mentioned season, but they were nevertheless in 

 full vigoiir and development. However it is most vigourously developed here in suni- 

 mer. I have collected specimens with zoospores in August on the coast of Spitzbergen 

 and Finmarken. 



Geogr. Distrib. This species has an extensive range in the Arctic Sea. Its maxi- 

 mum of frequency is on the north coast of Norway. Its northernmost certain locality 

 is Low Island on the north coast of Spitzbergen Lat. N. 80° 20'. 



Localities: The Norwegian Polar Sea: Nordlanden; Tromsö amt at Tromsö, Renö, 

 and Karlsö; Finmarken: Maasö, Gjesvser, the south coast of Magerö, Talvik, common 

 and abundant everywhere. 



IVie Greenland Sea: Beeren Eiland; the north; and west coast of Spitzbergen, 

 commonly distributed, but in very small numbers. 



The Mur man Sea: at several places on the west coast of Novaya Zemlya and 

 Waygats, but very scarce. 



The White Sea: Solowetzki Isles. 



The Kära Sea: scarce in Actinia Bay. 



K. Vet. Aknd. Handl. Bd 20, N:o 5. "^ 



