205 



but no doubt also of different species of blue-grecn algæ, I cannot 

 say for certain which species, as I have not had any material for 

 exaniination. 



Lastly, I shall only mention the ricii vegetation of Prasiola 

 crispa (and »Schizogoninm murale(^) together with species of Meso- 

 tænium, etc. commonly found on moist grass roofs. F'urther a pale- 

 green coat of Pleurococcus viilgaris often growing to the thickness 

 of a millemetre which covers all unpainted wooden surfaces, espe- 

 cially the »Kelds« in the villages. 



I render sincere thanks to all those who have assisted me with 

 this work, especially to Miss Emma Ha Has, who has very kindly 

 determined the Oedogoniaceæ found in the Færoes, to Dr. Otto 

 Nordstedt, who has not only determined the Characeæ, but also 

 assisted me in other ways, and to Mr. Lemmermann, Bremen, 

 who kindly determined some Plankton-algæ. 



List of abbreviations. 

 Hydrophyt. = Hans Christian Lyngbye: Tentamen Hydro- 

 phytologiæ Danicæ. Hafniæ 1819. 



Fær. FL = E. Rostrup: Færøernes Flora. (Botanisk Tidsskrift, 

 vol. IV. 1870—1). 



Wille (l.c.) = N.Wil le: Om Færøernes Ferskvandsalger og om 

 Ferskvandsalgernes Spredningsmaader. (Botaniska Notiser. 1897.). 

 Vid. = Videro. Ost. = Ostero. 

 Str. = Stromo. Syd. = Sydero. 



I. Cyanophyceæ. 

 Order I. CHROOCOCCACEÆ. 



1. Chroococcus macrococcus Rabenh. 



Rostrup (Fær. Fl. p. 90) reports having found this species: »On rocks 

 amongst Ephebe and on damp peaty soli near Sandegærde«. I found 

 it to be part of some green gelatinous ckimps which Mr. Helgi Jonsson 

 had collected from the bottom of a small pond near Thorshavn (Str.). 



2. C. rufescens (Bréb.) Nagl. 



Found by Rostrup (Fær. Fl. p. 90): »Amongst Ephebe*. 



3. C. turgidus Nagl. 



Rostrup (Fær. Fl. p. 90) reports having found it: »On moss, Stromo«. 

 I found it in collections from Thorshavn, Gliversrejn and Hojvig on Str.; 

 and from bare stony ground (Fjeldmark) on Bordo (450 m.). 



