Contribution. I. 47 



stunted one produced by unfavourable conditions of life, and 

 it passes gradually into the typical form without any limit. 



The present plant is at East-Finmarken, as far as I have 

 seen, always sublitoral, and appears in the upper as well as 

 in the lower part of the zone, attached to Lithothamnia and 

 shells of Balanidse. Solitary specimens have also been found 

 fastened to Delesseria sinuosa, Ptilota plumosa and the root- 

 tuft of Polysiphonia arctica. Sometimes it grows gregarious 

 but not in large number. It is best developed in much ex- 

 posed localities, and does not enter into the deeper bays. I 

 have collected specimens with tetrasporangia in the middle 

 of June at Kjollefjord, rather richly; at Mehavn at the end 

 of June, sparingly; and at Berlevaag in the middle of July, 

 rather richly. 



Distribution: Commonly spread but scarce along the 

 unsheltered coast; at Berlevaag found in considerable abun- 

 dance on an iron buoy. 



Antithamnion boreale Gobi (Kjellm.) 

 N. Ish. Algfl. p. 226; Antithamnion plumula var. boreale Gobi, Algenfl. 

 Weiss. Meer. p. 47. 



f. typica Kjellm. 



N. Ish.. Algfl. p. 226. 

 Descr. Antithamnion plumula var. boreale Gobi J. c. p. 47 et sequent. 

 Fig. . „ boreale f. typica Kjellm. 1. c. t. 16, fig. 2— 3. 



f. corallina Rupr. (Kjellm.) 

 Descr. Cahithamnion corallina Rupr. Alg. Och. p. 340. 



Antithamnion corallina Kjellm. Algenw. Murm. Meer. p. 24. 

 Fig. „ boreale f. corallina Kjellm. N. Ish. Algfl. 1. 16, fig. 4 — 5. 



Syn. Antithamnion plumula Kjellm. Spetsb. Thall. 1, p. 26. 



I have only seen a comparatively small number of this 

 species, and especially at East-Finmarken it is dwarfed, sel- 

 dom, if ever, reaching more than 3 — 4 cm. in height, most 

 commonly about 1 cm. It is often very difficult to distinguish 

 from A. Pylaiscei, particularly when growing together with 



