787 



As the Shetland I si es ave of about the same size as the Fær- 

 oes and lie nearest to Ihe latter (the distance is almost 300 kilo- 

 meters), a comparison between the marine algæ- flora of these two 

 groups of islands would be particularly interesting. It is therefore 

 to be regretted, that the marine algæ-vcgetation of the Shetland Isles 

 has been but little investigated. The most important contribution to 

 our knowledge of these algæ is to be found in Edmonston's Flora 

 of the Shetland Isles (16) with a list of the marine algæ known at 

 that period. Since then no other contribution had been published, 

 so far as I know, until 1902 when I paid a short visit to the islands. 

 In a small paper (9) I have published my discoveries and added the 

 species mentioned by Edmonston. The number of species known 

 from the Shetland Isles is about 108, as I include Enteromorpha cla- 

 thrata and Callithamnion tetragoniim var. brachiatum, whilst Gelidium 

 cartilagineiim must be left out, as it does not belong to the flora 

 of the islands. Of these 108 species, about 88 are also found 

 at the Færoes; of Rhodophijceæ and Phæophyceæ 87 have hitherto 

 been known, of which 72 are common to both countries. But 

 as already emphasized by me in dealing with the flora of Scot- 

 land and adjacent islands, there is hardly any doubt, that by 

 far the greater part of the algæ-species of the Færoes will be found 

 there, especially on the islands that are the nearest. The only spe- 

 cies which have less likelihood of being found there are the above 

 mentioned 6 subarctic species, to which perhaps may be added a 

 few more, e. g. Laminaria færoensis, Phæostroma parasiticiim etc. Of 

 the 20 species found at the Shetland Isles but not at the Færoes we 

 must first mention Fiicus serratiis which is very common at the Shet- 

 land Isles but is, strangely enough, wanting at the Færoes; the 

 other 19 are: Helminthora diuaricata , Chylocladia kaliformis, Nito- 

 phyllum Bonnemaisonii, Spermothamnion Tiirneri, Callithamnion te- 

 tragoniim, Ceramiiim diaphaniim, C. ciliatum, Dilsea ediilis, Aspero- 

 coccus biillosiis, Myriotrichia clavæformis, Mesogloia vermiculata, Sac- 

 corhiza biilbosa, Cutleria miiltifida, Fiiciis ceranoides, Acinetospora 

 piisilla, Chætomorpha ærea, Cladophora Hutchinsiæ, Dermocarpa 

 prasinu and Calothrix confervicola. It is not impossible, that some 

 of these species may grow on the Færoese coasts, but most of them 

 are forms from more southern countries, most likely having their 

 northern limit at the Shetland Isles. 



It appears from this, that the Færoese algæ- flora must be regarded 

 as a rather poor selection of the algæ of Scotland and adjacent is- 



