743 



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

 geniiina, especially the formå cornucopiæ. Together with Entero- 

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

 riipincola. 



This association is closelj' related to the Enteromorpha-assocm- 

 tion, which has been mentioned as characteristic on exposed coast 

 (p. 714), and to the Enteromorpha-vegetalion which is found in the 

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

 romorjo/ia- formation« found by Hansteen (38, p. 358) at the head 

 of the Vindefjord. 



The Fucaceæ- 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 Fucaceæ: Peluetia canali- 

 ciilata uppermost, next to that Fuciis spiralis, F. vesiculosiis, Asco- 

 phijlhim nodosiim, and lastly Fiicus inflatus, which grows a little 

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

 these five Fucaceæ 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 piaces Peluetia, Fucus vesiculosus 

 and Ascophijllum will generally predominate, whilst Fucus spiralis 

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

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

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

 culosus, and later Ascophyllum totally disappear. Peluetia may still 

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

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

 left. These two algæ 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 Fucacé- 

 formalion 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 Rosen vi nge's report (71, p. 197). 

 I also entirely agree with Rose uvinge, when he declares, that 

 Fucus vesiculosus grows the farthest into the fjords, where the 

 water 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 irrigaled by fresh water, but 



