204 



are, however, some algæ which either by their size or by their 

 abundance attrået attention. 



At the bottom of smaller lakes and along',the margins of larger 

 ones a Characé-formation is often met with, which is rich in 

 individuals, but not in species, in faet only two were found, viz. 

 Chara fragilis and Nitella opaca; on the latter was found Coleochæte 

 Nitelleariim Jost, which is a characteristic epiphyte on Nitella. 



Along the margins of the lakes and in the watercourses can 

 be seen a wavy fresh green vegetation consisting of different fila- 

 mentous algæ {Ulothrix, Conferva, Microspora, Conjiigatæ, etc.) and 

 sometimes also Draparnaldia glomerata. In the Sub-Alpine water- 

 courses on Gliversrejn near Thorshavn an Enteromorpha-xegelalion 

 was already found by Lyngbye, and it was not only re-found liere, 

 but again on Fuglo at an attitude of 200 metres. 



Also the Cladophora species can here and there form societies. 

 Thus Ostenfeld found in the lake near Kvalbo Ejde a species of 

 Cladophora, which I think may be referred to Cl. glomerata f. ma- 

 crogonia Lyngb. ; it grew abundantly at the bottom and close to 

 the margin of the lake. 



Large areas of moist peaty soil are frequently covered with a 

 thin carpet of different kinds of algæ often tinged red-violet by 

 Phycoporphyrin. Conjiigatæ were most frequently met with in such 

 localities; a sterile Zygnemacé — probably a form of Zygogoniiini 

 ericetoriim — may be named as especially characteristic; this was 

 the most numerous and in this was also mixed Mougeotia, Cylindro- 

 cystis, a few blue-green algæ, e. g. Oscillatoria limosa, Chroococcaceæ 

 and others. 



In peat-holes, in bog pools and in shallow lakes here as else- 

 where a luxuriant growth of algæ is very naturally found and in 

 sheltered localities amongst Sphagnum and Myriophylliim a vegeta- 

 tion of algæ rich in species may be met with in which numerous 

 species of Desmids play a prominent part. On the other harid 

 many of the Alpine lakes containing water clear as crystal are 

 apparently void of algæ-vegetation ; but most of them seem to 

 contain Plankton though not in great quantities, and a few spe- 

 cies, e. g. Staurastriim jaciiliferum, Xanthidiiim quadricornutum and 

 some blue-green algæ have been only found in Plankton. 



Everywhere in the Færoes where the water ripples down the 

 rocks »sorte striber« (black stripes) are prominent (see fig. 14 in the 

 »Introduction«), they are not only composed of several other piants. 



