743 



are met with here: var. micrococca uppermost, next to that var. 

 geniiina, especially the forma cornucopice. Together with Knlero- 

 morpha, Ectocarpus litoralis is also often found, especially the form 

 riipincola. 



This association is closely related to the Enteromorpha-Sissoc'isi- 

 tion, which has been mentioned as characteristic on exposed coast 

 (p. 714), and to the Enteroniorpha-\ege[Si{ion wiiich is found in the 

 highest littoral pools. It seems to correspond exactly with the »Ente- 

 romor/;/?a- formation « found by Hansteen (38, p. 358) at the head 

 of the Vindefjord. 



The Fucacece- Formation. 



On sheltered coasts, especially in the littoral region, a very 

 characteristic and luxuriant vegetation is found both on rocks and 

 stones and consists almost entirely of the Fucacece: Pelvetia canali- 

 ciilata uppermost, next to that Fucus spiralis, F. vesiculosus, Asco- 

 phyUiim nodosum, and lastly Fucus inflaius, w^hich grows a little 

 above and sometimes a little below the lowest water mark. As 

 these five Fucacece are differently adapted to resist the dashing of 

 the waves or the supply of fresh water, they are not always found 

 together. In the most sheltered places Pelvetia, Fucus vesiculosus 

 and Ascophyllum will generally predominate, whilst Fucus spiralis 

 and F. in flatus are absent entirely or only represented by a few 

 scattered individuals. Where the coast begins to be more exposed, 

 the two last-mentioned algae appear. At the same time, Fucus vesi- 

 culosus, and later Ascophyllum totally disappear. Pelvetia may still 

 be found in rather exposed places, but in the most exposed it like- 

 wise disappears, so that only Fucus spiralis and Fucus inflatus are 

 left. These two algse may be typically developed on a somewhat 

 exposed coast, but the more exposed it is, the smaller the Fucus- 

 species. Thus they pass easily into the above-mentioned Fucace- 

 formation found even on the most exposed coasts. 



With regard to the species found on the coasts of Greenland, 

 Fucus vesiculosus, Ascophyllum nodosum and Fucus inflatus., these 

 observations agree well with Rosenvinge's report (71, p. 197). 

 I also entirely agree with Rosenvinge, when he declares, that 

 Fucus vesiculosus grows the farthest into the fjords, where the 

 Waaler may be almost fresh because of the inflow of rivers. Yet 

 Ascophyllum may sometimes be found growing at the outlet of 

 rivulets, where the alga at low-tide is irrigated by fresh water, but 



