118 M - Foslie. 



rather exposed localities. I have collected specimens with 

 zoospores in the later half of June and in July. 



Distribution: Common and mostly plentiful all along 

 the open coast. 



Monostroma arcticum Wittr. 



Monostr. p. 44. 

 Descr. Monostroma arcticum Wittr. 1. c. 

 Fig. „ „ „ „ t. 2, fig. 8. 



Exiscc. „ „ Wittr. et Nordst. Alg. exsicc. Nr. 144. 



By a cross section of the monostromatic part of the 

 frond of this species, the ceils are not always horizontally 

 ovale, but sometimes roundish, vertically ovale, or even ver- 

 tically rectangular with rounded corners. The plant is li- 

 toral, chiefly growing in rock-pools in the upper part of the 

 zone, fastened to Corallina officinalis or other algse, or atta- 

 ched to shells of BaLanida3. It seems to occur only on open 

 coast. Specimens with zoospores have been . taken in the 

 later half of June, in July and in the first part of August. 



Distribution: Pretty common along the open coast and 

 at several places rather plentiful. 



Monostroma fuscum (Post, et Rupr.) Wittr. 

 Monostr. p. 53; Ulva fusca Post, et Kupr. 111. Alg. p. 21. 

 Descr. Monostroma fuscum Wittr. 1. c. 

 Fig. „ „ n „ t. 4, fig. 13. 



Exsicc. Ulva sordida Aresch. Alg. Scand. exsicc. Nr. 120. 



Monostroma fuscum Wittr. et Nordst. Alg. exsicc. Nr. 143. 

 „ „ Hauck et Richt. Phyc. univ. Nr. 124. 



Syti. Ulva sordida Aresch. Phyc. Scand. p. 4J3. 



This alga is, in general, sublitoral, occurring in the 

 upper part of the zone, but sometimes also appearing in the 

 lowermost part of the litoral zone, on open coasts as well 

 as sheltered ones. It frequently grows on stones or shells. 

 Specimens with zoospores have been taken in August, 



