18 M. Foslie. 



developed it appears on rocks at low-water mark on exposed 

 places, more seldom in rock-pools between tides, and it grows 

 often gregarious in rather considerable masses. In the sub- 

 litoral zone, to the lowest limit of which it sometimes descend, 

 it occurs more scattered. Here it always prefers solid rocky- 

 bottom, sometimes also it is found on looser or even on 

 clayish bottom, but at such places it assumes loosely entang- 

 led and sparingly branched tufts. It is usually met with on 

 a depth of 3 — 10 fathoms in company with Ptilota, Delesseria 

 and Rhodophyllis, or epiphytic especially on the first one. 

 Often it almost covers Ptilofa pectinata forming rather brist- 

 ly and sparingly branched threads, or loosely entangled tufts. 

 It also often grows in large numbers on the stems of Maria 

 or more commonly Laminaria hyperborea within the upper 

 part of the sublitoral zone. The plant has generally a length 

 of 8—15 cm., but not rarely it becomes 20 cm. long. It bears 

 tetraspores in the later half of June, in July and August; 

 sporocarps in July and, more richly, August. 



Distribution: Common and mostly abundant along the 

 open shore, but it also enters almost to the end of the great 

 bays. The form patens has only been found at Berlevag; f. 

 formosa at Vardo and Sveerholt; f. comosa at Syltefjord and 

 Svserholt; and f. roseola at Svserholt. 



Polysiphonia fastigiata (Roth.) Grev. 



Fl. Edinb. p. 308; Ceramium fastigiatum Roth, Fl. Germ. 3, p. 463. 

 Bescr. Polysiphonia fastigiata J. G. Ag. Spec Alg. 2, p. 1029. 

 Fig. „ „ Harv. Phyc. Brit. t. 299. 



-Exsicc. „ „ Aresch. Alg. Scand. exsicc. No. 4. 



Syn. Conferva omissa Gunn. Fl. Norv. 2, p. 78. 

 „ polymorpha Gunn. 1. c. p. 92. 



„ „ Wg. Fl. Lapp. p. 511. 



Hutchinsia fastigiata Sommerf. in Act. Nidros p. 51. 



The species is litoral and occurs at East-Finmarken only 

 on the same host plant as elsewhere, Ozothallia nodosa. All 



