KONGL. SV. VET. AKADEMIENS HANULINGAR. BAND. 20. N:0 5. 173 



Ptilota plumosa (L.) Ag. 



Syn. Alg. p. 39, excl. /?. Fucus plumosus L. Maiit. p. 134. 

 Descr. Ptilota plumosa J G. Ag. Epicr. p. 75. 

 Fig. » » IIakv. Phyc. Brit. t. 80. 



ExsicG. > » Abesch. Alg. Scand. exsicc. N:o 160. 



Syn. Fucus plumosus R. Bvl. in Scoeesby, Account., 1, p. 132 et append V? Nonne Pt. pectinata? 

 » » GoNN. Fl. Norv. 2, p. 91. 



» » a et fi Wg. Fl. Lapp. p. 501. 



» ptilotus GuNN. Fl. Norv. 2, p. 135. 

 Plumaria pectinata var. tenerrima Rdpk. Alg. Gcli. p. 336. 

 Ptilota plumosa J. G. Ag. Spetsb. Alg. Progr. p. 3; Bidr. p. 11. 

 » » Aresch. Phyc. Scand. p. 319. 



» » a typica Gobi, Algenfl. Weiss. Meer. p. 44. 



» « Hahv. Ner. Am. 2, p. 224. 



» » Kjellm. Spetsb. Tliall. 1, p. 26; Algenv. Murra. Meer. p. 22. 



» » Kleen, Nordl. Alg. p. 20. 



» » Lyngb. Hydr. Dan. p. 38. 



« » var. tenuissima ScriiJBELEii in Heugl. E-eise, p. 317. 



» » WiTTii. in Heugl. Reise, p. 284. 



Habitat. This species is generally sublitoral, occurring in 5 — 20 fathoms water 

 on stony or pebbly bottom. Sometimes it is found in more shallow water, even within 

 the literal zone in rock-pools between tides. It is attached sometimes to other alga?, 

 usually to stones, and grows on exposed coasts as well as in the interior of bays and 

 at other sheltered places. I never found it gregarious. On the coasts of Spitzbergen 

 and Novaya Zemlya it usually constitutes an element of the LaminariacoB-formation; on 

 the west coast of Norway I have generally found it in company with purely arctic 

 algse. Here it attains a high degree of luxuriancy. The largest specimens I ever 

 saw, from the interior of Altenfjord, had a length of 20 — 25 cm. The plant has not 

 been examined in winter in the Polar Sea. Individuals with sporocarps have been 

 found at Nordlanden in July and August, at Finmarken at the end of August and in 

 the earlier part of September, at Spitzbergen in July, on the west coast of Novaya 

 Zemlya and Waygats in August and at the end of June. Specimens with tetrasporangia 

 have been collected in most of these parts of the Arctic Sea in July and August. 



Geogr. Distrib. The present species belongs both to the Atlantic and the arctic 

 region of the Polar Sea, having its maximum of frequency within the former. Its most 

 northerly known locality is the outer Norse Island off the north-western coast of Spitz- 

 bergen Lat. N. 79° 50'. 



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

 marken: Maaso, Gjesvter, Magero Sound, Oxfjord, and Talvik, abundant, but local. 



The Greenland Sea: According to my experience, local and scanty on the coasts 

 of Spitzbergen. 



The Murman Sea: the coast of Cisuralian Samoyede-land; the west coast of No- 

 vaya Zemlya and Waygats from Matotshin Shar to Jugor Shar, pretty common and 

 abundant. 



