Contribution. I. 113 



This species is nearly related to certain forms of Pylai- 

 ella litoralis. It differs by its long chains of zoosporangia 

 and very long gametangia, the former in a number of until 

 40, the latter 180 — 1320 \x long, and by the subsecund bran- 

 ches of the last and the last but one order, the latter most- 

 ly issuing in pairs. 



The plant is litoral and sublitoral. In the former case 

 growing in rock-pools fastened to Laminaria digitata. In the 

 latter case attached to the stipe of Alaria on a depth of 

 2 — 5 fathoms. It bears zoosporangia in June. At Tromso 

 I have collected specimens with zoosporangia and gametangia 

 in the beginning of August. They have sometimes been found 

 in one and the same individual, or even joining each other. 



Distribution: Found at Kjollefjord, scarce, and at Me- 

 havn, rare. 



Pylaiella varia Kjellm. 



N. Ish. Algfl. p. 348. 

 Descr. Pylaiella varia Kjellm. 1. c. 

 Fig. „ „ „ „ t. 27, fig. 1-12. 



Sublitoral, occurring on a depth of 2 — 5 fathoms. Spe- 

 cimens taken in the middle of June were sterile. I have col- 

 lected zoospore-bearing ones at Tromso in the beginning of 

 September, in rock-pools between tides among other algse. 



Distribution: Found only at Kjollefjord, rare. 



Ser. Chloropliyceae (Kabenli.) Wittr. 



Pithoph. p. 42; Rabenh. Fl. Eur. Alg. 3, p. 1; lim. mut. 



Fam. Ulvacese (Ag.) Rke. 



Ostseefl. p. IX; Ag. Syst. Alg. p. XXX; lim. mut. 



Gen. Monostroma (Thur.) Wittr. 

 Monostr. p. 15; Thur. Note s. Ulv. p. 29, s«c. Wittr, 1. c; lim. mut. 



