KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND. 20. N:0 5. 187 



Subg. 2. Thamniscus Kjellm. 



Spetsb. Thall 1, p. 29. 



Rhodochorton mesocarpum (Carm.) nob. 

 Callithamnion mesocarpum Carm. in Hook. Brit. PI. 2, p. 348. 



f. rupicola nob. 

 Descr. Thamnidium mesocarpum Klben, Nordl. Alg. p. 22. 

 Fig. Callithamnion » Harv. Phyc. Brit. t. 325. 



f. penicilliformis Kjellm. 

 Spetsb. Thall. 1, p. 30. 

 Descr. Thamnidium mesocarpum f. penicilliformis Kjellm. 1. c. 



Fig. » » » » tab. nostra 16, fig. 6 — 7. 



Syn. Thamnidium mesocarpum Klebn, Nordl. Alg. p. 22. 



» » f. penicilliformis Kjellm. 1. c; AJgenv. Murm. Meer. p. 25; Kariska 



hafvets Algv. p. 23. 



Addition to the description of f. penicilliformis. In general the appearance of this 

 plant is that represented by fig. 6. I have always found it such within the Arctic Sea. 

 On the coast of Finmarken among such individuals I have, besides, observed others 

 whose primary branches bore a greater number of secund or alternate, appressed branches. 



Habitat. The form rupicola is literal or sublitoral, attached to stones, Bryozoa, 

 muscles a. o. The form penicilliformis is sublitoral and epiphytic on several algae, chiefly 

 species of Odonthalia, Delesseria, and Ptilota, and Chcetomorpha melagonium. It has been 

 met with hitherto only on exposed coasts, always few specimens. Both the forms 

 have been found with tetrasporangia in July and August, f. 'penicilliformis, besides, at 

 Greenland in March. 



Geogr. Distrib. The typical form is known only from the Atlantic province of 

 the Polar Sea, f. penicilliformis also from the arctic region, within which it is widely 

 diffused. Its most northern known locality is Fairhaven on the north-west coast of 

 Spitzbergen, Lat. N. 79° 41'. 



Localities: The Norwegian Polar Sea: Nordlanden (f. rupicola) local, scarce; Fin- 

 marken at Gjesvser (f. penicilliformis) local, scarce. 



The Greenland Sea: the north-west coast of Spitzbergen at Fairhaven, local, scarce. 



The Murman Sea: on the west coast of Novaya Zemlya at several places pretty 

 plentiful. 



The Kara Sea: Uddebay on the east coast of Novaya Zemlya. 



Baffin Bay: the west coast of Greenland at Julianeshaab. 



Rhodochorton spetsbergense Kjellm. 



Spetsb. Thall. 1, p. 31. 

 Descr. Thamnidium spetsbergense Kjellm. 1. c. 

 Fig. » , » » t. 1, fig. 11, 12. 



