KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 273 



Gen. Ohsetopteris Kutz. 



Phyc. gener. p. 293. 



Ohsetopteris plumosa (Lyngb.) Kutz, 



1. c. Sphacelana plumosa Lyngb. Hydr. Dan. p. 103. 



Descr. Chsetopteris plumosa J. G. Ag. Spec. k\g. 1, p. 41. 

 Fig. Sphacelana plumosa Hakv. Phyc. Brit. t. 87. 



Ohsetopteris plumosa Aresch. Obs. Phyc. 3, t. 2, iig. 4. 



» » Kjellm. Spetsb. Thall. 2, t. 2, fig. 2—3. 



Exsicc. Sphacelana plumosa Aresch. Alg. Scand. exsicc. N:o 107. 



Ohsetopteris plumosa Kjellm. in Aresch. Alg. Scand. exsicc. N:o 408. 

 Syn. Ohsetopteris plumosa J. G. Ag. Gronl. Alg. p. 110. 



» » Dickie, Alg. Sutherl. 1, p. 141; 2, p. 191; Alg. Oiimberl. p. 238; Alg. 



Nares, p, 7. 

 » » Gobi, Algenfl. Weiss. Meer. p. 63. 



» » Harv. 51. West-Esk. p 49. 



■> » Kjellm. Vinteralgv. p. 65; Spetsb. Thall. 2, p. 32; Algenv. Murm. Meer. p. 



42 , Kariska hafvets algv. p. 27. 

 » » Kleen, Nordl. Alg. p. 35. 



» » KupR. Alg. Och. p. 378. 



Conferva pennata Wg. F1. Lapp. p. 512; ex parte. 

 Sphacelaria plumosa J. G. Ag. Spetsb. Alg. Progr. 2; Bidr. p. 11. 

 » » Croall, F1. Disc. p. 458. 



» » Eaton. List. p. 44. 



» » Lyngb. 1. c. 



» » Post, et B,upr. 111. Alg. p. II. 



Habitat. In the Norwegian Polar Sea this species usually grows in rock-pools 

 within the litoral zone, occasionally attached to stones within the sublitoral. In other 

 parts of the Polar Sea it is almost without exception sublitoral, keeping however chiefly 

 in the upper part of this zone. It is usually found in 2 — 5 fathoms. It is a common 

 element of the formation of Laminariacece, but occurs also within other formations. 

 It prefers gravelly and stony bottom. At Spitzbergen it is not seldom gregarious, 

 occurring in rather considerable masses. It flourishes both in exposed and sheltered 

 localities, and is even found far off from the coast. Kleen has collected specimens 

 with gametangia in August at Nordlanden. At Spitzbergen it bears reproductive organs, 

 zoosporangia and gametangia, from November to May, most plentifully from the middle 

 of November to the beginning of March. After the end of March individuals with such 

 organs were rare. In other parts of the Arctic Sea I have only had an opportunity 

 of examining specimens of this alga in summer and autumn, and at these seasons I have 

 always found it sterile. 



Geogr. Distrib. This species is circumpolar, common in the Arctic Sea, and very 

 abundant at certain places. According to my observations its maximum of frequency 

 and luxuriancy is in the eastern part of the Greenland Sea on the coasts of Spitzbergen. 

 Its northernmost point is in Smith Sound Lat. N. 82° 27'. 



K. Vet. Akad. Handl. Bd 20. N;o S. o5 



