MARINE ALGAL VEGETATION 



115 



plants is also usually broader. In this belt the broad forms are to 

 be found; they may occur both with and without air-bladders. This 

 belt is as a rule poorly developed, and is often non-continuous. 

 Within HvammsfjorSur, in bays protected from the surf, but where 

 current-movements are felt to a certain extent, I have observed, 

 below low- water mark, semi -littoral stragglers from the Fucus- 

 community (i. e. from the Fucus in flatus-association). In a similar 

 locality I saw AscophyUum occurring semi-littorally. 



Fig. 6. Fucus inflcitus (sterile plants) lying prostrate upon the rocks. Above, hanging 

 AscophyUum. Reykjavik, Aug. 13, 1909. (From phot, by Hesselbo.) 



The Fucus serratus-association was especially luxuriant 

 in Hafnarfjor5ur on both sides of the fjord, some distance from 

 the head of it, and occurred lowest of all in the Ftzcacece-community. 

 In the Vestmannaeyjar the species grew scattered here and there, 

 but was not found in the most exposed places. Sometimes on ex- 

 posed coasts it was found growing in pools in the middle of the 

 littoral zone. 



The Epiphytes and Intermixed Species of the Fucus- 

 belt. As is well known, an abundance of epiphytic vegetation 

 exists in the Fucus-belt, at any rate at times. Many of the species 

 grow socially and often occur in such quantities, that they set their 

 stamp upon the vegetation. These species may be divided into those 



