754 



washed by Ihe sea, Alaria esciilenta may exceptionally be found up 

 to several feet above the lowest water mark, as at Myggenæs Holm, 

 wheie it gro\YS up to at least 10 feet above tbe lowest water mark, 

 tbat is to say, it passes above the highest water mark (see fig. 159). 

 Other piaces where it grows under the same conditions, are e. g. 

 Lille Dimon, Molen at Ejde, etc. (see also plate XXI). 



The A/ar/a-association prefers steep or perfectly vertical rocks 

 in the most exposed piaces, and covers these rocks with a dense 

 covering, often many feet thick, at varying but hardly ever very great 

 depths. Yet the Alaria may be found at a de])th of several fathoms, 

 as in sounds where there is a rapid current. Here the Alaria is 

 often richly represented in the Laminaria hyperborea-associaiion. 



The Alaria is excellently adapted to the violence of the waves; its 

 elastic leaves constantly follow the motion of the water, as their great 

 flexibility makes them utterly unresisling. In spite of this, the upper- 

 most part of its lamina clearly shows traces of the force of the sea 

 on exposed coasts, as it is torn and rent into small lobes, and 

 lastly nothing but the bare, thin, much-worn midrib is left (see the 

 illustration of this alga in my flora, p. 449). 



Generally the association consists solely of the Alaria esciilenta; 

 the Alaria Pylaii seems to prefer somewhat more sheltered coasts, 

 and it may be supposed that this species is rare, as only a few 

 specimens of it have been found. It is therefore of no importance 

 in reference to the composition of the A/arza-association. On the 

 other band, the Litosiphon Laminariæ, which is almost always found 

 abundantly on the leaves of the Alaria, and the Chantransia Alariæ, 

 which covers the lamina with a very dense, purpie, velvet mat, are 

 very characteristic in the association. I have however only seen 

 the latter a few times on the coasts of the Færoes. On old stems 

 of Alaria a number of different epiphytes are found; some of these 

 are Ectocarpiis fasciciilatiis , E. Hincksiæ and E. tomentosiis , Rhody- 

 meiiia palmata, Porphyra iimbilicalis, Ulothrix flacca, etc. 



Larger algæ but rarely belong to the association; however, La- 

 minaria saccharina f. linearis may be found more or less abundantly, 

 as well as Laminaria digitata f. stenophyUa, which may in some 

 piaces be found on slightly sloping rocks even far up in the litto- 

 ral region, as will be mentioned below. In narrow inlets of shal- 

 low water lying between rocks and small islands, »Skærgaarde«, 

 e. g. those mentioned before on the east coast of Stromo, north 

 of the redoubt, large numbers of Laminaria saccharina f. bullata 



