150 KJELLMAN, THE ALGM OE THE AKCTJC SEA. 



have found here partly young plants, from such ones as were in gennination to iudi- 

 viduals of about one inch in length, partly older plants, some of which were in full 

 vigour, developing new shoots, while othei's were uiore or less corroded and dissolved. 

 From the beginning of December to the middle of May young individuals were common; 

 most of thein were sterile, others developing tetrasporangia. The older specimens 

 during this period were almost always furnished with tetrasporangia. As far as I could 

 see, the present alga on the coast of Spitzbergen is only annual, but during its life 

 produces tetrasporangia at least twice, once when young, the other time immediately 

 before dying. It is possible, however, that it develops such organs several times, for 

 on the north and north-west coasts of Spitzbergen it bears ripe tetrasporangia also 

 during the summer and the earlier part of the autumn, in July and October, espe- 

 cially in July, when it reaches its highest vegetative development. On the coast af 

 Finmarken I have found only sterile specimens. At Nordlanden it seems also to be 

 sterile in summer. Kleen does not mention having found any individuals with repro- 

 ductive organs during his summer visits there, nor are any to be found in his collections. 

 The season for developing the tetrasporangia is probably here as farther southwards 

 the winter. On the west coast of Novaya Zemlya I have collected specimens richly 

 furnished with tetrasporangia in June and July. 



Geogr. Distrib. The species appears to be limited to those parts of the Polar 

 Sea which are situate north of the Atlantic. Although certainly attaining its maximum 

 of frequency in the Norwegian Polar Sea, it is commonly spread and often met with 

 in very large numbers even in the arctic parts of the Polar Sea. The northernmost 

 place where it has been found as yet is Miisselbay on the north coast of Spitzbergen 

 Lat. 79° 53' N. 



Localities: The Norwegian Polar Sea: Nordlanden, common and abundant; Fin- 

 marken, common and abundant at Maasö, Gjesvajr, the south coast of Magerö, Ox- 

 fjord, Talvik. 



The Gréenland Sea: the coast of Russian Lapland, the west coast of Novaya 

 Zemlya and Waygats from Matotshin Shar to Jugor Shar, common and abundant at 

 least at the latter place. 



The White Sea: rare, according to GoBi 1. c. 



Baffin Ba.y: Cumberland Sound, the west coast of Gréenland in several places, 

 as Tessarmiut, Nanortalik, Kakortok, Sukkertoppen, and Jakobshavn. 



All the forms of the present species are met with in the Norwegian Polar Sea; 

 besides, f. typica is found in the Gréenland Sea, the eastern Murman Sea, and Baffin 

 Bay, f. sarniensis, or a form most nearly related to this, in the western Murman Sea. 



Rhodymenia pertusa (Post. et Rupe.) J. G. Ag. 



Speo. Alg. 2, p. 376; Porphyra pertusa Post. el Rupii. 111. Alg. p. 20. 

 Bisc?: Rhodymenia pertusa J. G. Ag. Spec. Alg. 2, p. 376 et Epicr. p. 329. 

 Fig. Porphyra pertusa Post. et Eupr. 1. c. t. 36. 



Si/n. Rhodymenia pertusa Kjellm. Spetsb. Thall. 1, p. 15. 



