74() 



in flatus occurs. On a more exposed coast, the latter forms an 

 extensive association (figs. 157 and 158). Both in the Fiiciis spiralis- 

 and the Fiiciis zn//a/zzs-associations, Elachista fncicola is a very com- 

 mon epiphyte. On Fiicus inflatiis, several species of Ectocarpiis e. g. 

 Ectocarpiis tomentosiis, Ectocarpiis fasciciitatiis, etc. are often found. 

 On the rocks and stones, below and among these algae, especially 

 in the lowest Fiiciis inflatiis-assoc'mlion, one may find a great many 

 different algae, e. g. Porphijra iimbiticatis, Urospora mirabilis, Clado- 

 phora rupestris, Acrosiphonia albescens, Polijsiphonia iirceolata, Cera- 

 miiim riibrum, Gigartina mamillosa, Chondriis crispiis, etc. 



In order to characterize the Fwcacea^-formation more closely, I 

 shall give a description of some of the localities in which I have 

 met it at its greatest development. In Vestmanhavn , and a little 

 north and south of this gulf, in the Veslmannasund, between 

 Vaago and Stromo, a specifically well-developed Fzzcaceo'-formation 

 is found, on sheltered coasts. The tide rises rather high here, about 

 6 — 8 feet, and at low tide the formation is laid perfectly bare. 

 We find Pelvetia uppermost as a light yellow belt, almost a foot broad, 

 showing up the high water mark with an almost perfectly straight 

 line. Below tliis, we have some Fiiciis spiralis; this alga is abundant 

 only on somewhat more exposed coasts. The Fiiciis-Ascophijlliim- 

 association, which comes next, is however very luxuriant. As shown 

 in plate XXIII, the coast in certain places consists of large stones 

 which are completely covered by these algae. This vegetation is 

 found as far down as the lowest water mark, where some few 

 Fuciis inflatiis may occur. 



On the east coast of Stromo, between Thorshavn and Hojvig, 

 the Fzzcaceoe-formation is of a somewhat different appearance. The 

 coast is here rather exposed and rugged, with several larger or 

 smaller islands girding the coast. In one of the inlets, called Volga- 

 ravik, which forms a little natural harbour, having but a small 

 opening towards the sea, a well-developed Fzzcaceoe-vegetation was 

 found (see plate XXIV). Near the land, the coast was composed of 

 boulders of different size which were covered by a dense Fuciis- 

 vegetation; a little farther out, in a more exposed position, Fucus 

 vesiculosiis disappeared making way for a luxuriant Ascophylliim- 

 vegetation, which was replaced by a well-developed Fucus inftatus- 

 vegetation at the greatest distance from the shore and at a lower level. 

 Here, on the stones lying farthest from the shore, the position is 

 rather exposed, and in a strong sea making towards the land the surf 



