150 KJELLMAN, THE ALG OF THE ARCTIC SEA. 
have found here partly young plants, from such ones as were in germination to indi- 
viduals of about one inch in length, partly older plants, some of which were in full 
vigour, developing new shoots, while others were more or less corroded and dissolved. 
From the beginning of December to the middle of May young individuals were common; 
inost of them 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. KirEn 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 attaiing 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 Musselbay on the north coast of Spitzbergen 
oat: 79° 53' ON, 
Localities: The Norwegian Polar Sea: Nordlanden, common and abundant; Fin- 
marken, common and abundant at Maas6, Gjesver, the south coast of Mageré, Ox- 
fjord, Talvik. 
The Greenland 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 Gost 1. ce. 
Baffin Bay: Cumberland Sound, the west coast of Greenland 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 Greenland 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 Rupr.) J. G. Ac. 
Spec. Alg. 2, p. 376; Porphyra pertusa Post. et Rupr. Ill. Alg. p. 20. 
Discr. Rhodymenia pertusa J. G. AG. Spee. Alg. 2, p. 376 et Epicr. p. 329. 
Fig. Porphyra pertusa Posr. et Rupr. |. c¢. t. 36. 
Syn. Rhodymenia pertusa KseLiM. Spetsb. Thall. 1, p. 15. 
