801 



However, many widely distributed North-European species are, 

 as is well-known, wanting at North-America, e. g. CallophijUis la- 

 ciniata, Lomentaria clavellosa and L. articnlata, Delesseria samjiiinea, 

 Laiirencia pinnatifida, Polysiphonia Brodiæi, Griffithsia setacea, Calli- 

 thamnion scopulorum and C. arbnscula, Diimontia filiformis, Ptilota 

 phimosa, etc. On the other hånd, the coast of North-America has 

 some species that are wanting at the European coast; of these I 

 may mention: Grinellia americana, Polysiphonia vestita, P. Olnei 

 and P. Harueyi, Callithamnion Baileyi, Ceramiiim Hooperi, Ectocarpiis 

 Chordariæ, E. liitosiis. Stictyosiphon subsimpleæ, Dictyosiphon Macouni, 

 Scaphospora Kingii; to these must also be added Aganim Tiirneri 

 and Laminaria longicruris which are both very common on the 

 coasts of North-America and Greenland, but have not been found 

 further to the east. It is true, that Laminaria longicruris is stated 

 to have been washed asliore at certain piaces of the European 

 coasts, but it has never been found growing on any substratum, 

 and it is indeed very probable that these hollow stalks of Laminaria 

 are fragments of the very similar Laminaria færoensis, and have 

 come from the Færoes or Iceland. 



To what result does this comparison lead? As our know- 

 ledge of the floræ of several of the countries we have dealt with 

 is deficient, the result can only be somewhat hypothetical. First 

 of all it must be emphasized that the algæ-flora of the Færoes 

 is to be regarded as a scanty selection of that of North-Scotland, 

 with the addition of some few, more northern species not found 

 at the British Isles. If we had a more thorough knowledge of the 

 algæ-flora of the Shetland Isles, the flora of these islands and that 

 of the Færoes would certainly be found to agree well, just as the 

 algæ-vegetation of the Shetland Isles, at any rate the littoral vege- 

 tation, agrees well, with that of the Færoese coasts (compare 9). 

 The Færoese algæ-flora moreover much resembles that of South- 

 West Iceland; the algæ of this part of Iceland must be regarded 

 as a somewhat poorer selection of the algæ of the Færoes, still 

 "with a few more northern forms Ihan at the Færoes; lastly there 

 seems to be considerable resemblance between the algæ-flora of 

 the Færoes and that of Nordland. 



When the Danish issue of this paper was published, I did not 

 have the revised list of algæ which I have prepared later together 

 with Mr. Jonsson, and without which a thorough exami nation of 



