— 4. 



118 



' M. Foslie. 



rather exposed localities. I liave coUected specimens with 

 zoospores in the later half of June and in Jnlj, 



Distrihution: Comraon and mostly plentiful all along 

 the open coast. 



Monostroma arcticum Wittr. 



Monostr. p. 44. 

 Descr. Monostroroa arcticum Wittr, 1, c. 



Fig. ,; „ 



Exiscc. „ „ 



„ „ t. 2, fig. 8. 

 Wittr. et Nordst. Alg. exsicc. K"r. 144. 



By a cross section of the monostromatic part of the 

 frond of this species, the cells are not always horizontally 

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

 tically rectangnlar with rounded corners. The plant is li- 

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

 zone, fastenedto GoraUina officinalis or other algæ, or atta- 

 ched to shells of Balanidæ. It seems to occnr only on open 

 coast. Specimens with zoospores have been tåken in the 

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



Distrihution: Pretty common along the open coast and 

 at several places rather plentiful. 



Monostroma fuscum (Post. et Rtipr.) Wittr. 



Mono>str. p. 53; Ulva fusca Post. et Rupr. 111. Alg. p. 21. 



Beser, Monostroma fuscum Wittr. 1. c. 

 Fig. 



t. 4, fig. 13. 



w » s* »J 



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



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



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



» 



Syn. Ulva sordida Aresch. Phyc. Scand. p. 4J3, 



This alga is, in general, suhlitoral, 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 bave heen tåken in August, 



