773 



IV. 



THE PHYTO-GEOGRAPHICAL POSITION OF THE ALGÆ- 

 FLORA OF THE FÆROES. 



I. The constituent parts of the Færoese Algæ-flora. 



Before entering on a comparison between the marine algæ-flora 

 of the Færoes and that of neighbouring countries, we mav first of 

 all review the species occurring at the Færoes. 



In my paper on the Færoese marine algæ 212 species are men- 

 tioned, with 4 whose genus only was determined. On renewed in- 

 vestigation, however, I have come to the conclusion that one of 

 the latter, Chilionema spec. may be referred to Ch. reptans. Thus 

 we have 213 + 3 species. From this number, again, Dermatoli- 

 tohn Corallinæ (see my »Flora« p. 402) must be withdrawn as, ac- 

 cording to Mr. Foslie's latest investigations, kindly placed at my 

 disposal, it should be referred to Dermatolithon macrocarpum, or, as 

 he now calls it, LitophyUiim macrocarpum. Moreover Acrosiphonia 

 Binderi must be omitted, renewed examination of the present 

 material having proved that some imperfectly developed curved 

 branches occur, though but rarely, and this convinces me that it 

 should be referred to A. alhescens. 



Thus the number is reduced to 211 + 3, but to these must be 

 added Choreolax Polysiphonice, which I have discovered later^ 



In order to give a general view of the 212 + 3 species, and in 

 order to discuss more closely the elements of which the Færoese 

 algæ-flora consists, I have divided tliem, in accordance with the divi- 

 sion made by Jonsson and myself (12, page XV — XXI), into the 

 4 groups: the subarctic, the boreal-arctic, the cold-boreal 

 and the warm-boreal group (the ar et i c group is entirely wanting 

 in the Færoes). As to the hmitation of these groups, I may refer 

 the reader to the above-menlioned paper. It should not be forgotten, 

 however, that any such division must inevitably suffer from a certain 



' Besides these alterations, the name of the species, or of the genus, or of both 

 have been altered in the following list of Færoese algæ in the case of the following 

 species: Clathromorphiim circiimscriptiim which, according to Mr. Foslie, should 

 be referred to PhymatoUthon compactiim, Acrosiphonia flaccida, which I refer to 

 A. hijstrix (Stromf.) Borgs., as already pointed out bj' me (8, p. 512). The form 

 which I gave provisionalh' as Spongomorpha lanosa, and which I supposed to be 

 related to Sp. bombycina (Kjellm.), I have found on renewed examination to be 

 Spongomorpha vernalis. 



