796 



that of the Færoes, in so far that 4 species belonging to the arciic 

 group, which is quite wanting at the Færoes, have been foiind 

 at Iceland, as also that many more subarctic species occur there 

 than at the Færoes, the difference is much reduced, if we make 

 the comparison between the algæ-flora of South Iceland proper and 

 that of the Færoes. At South Iceland 82 red and brown species 

 and 26 green and bluish-green have been found, 108 species in all. 

 The following 12 of these species are wanting al the Færoes: 



Subarctic species: Lithothamnion topbiphorme, Ralfsia deiista, 

 Urospor a Hartzii, Cladophora hirta; 



Cold-boreal species: Rhodochorton repens (endem.), Petrocelis 

 Hennedyi, Rhododermis parasitica, Sphacelaria radicans, S. olivacea, 

 Fiicus serratiis, Acrosiphonia flabelliformis (endem.); 



Warm-boreal species: Bounemaisonia asparagoides, which 

 does not belong perhaps to the flora. 



As mentioned above, there is hardly any doubt, that at any 

 rate some of these species will also be found at the Færoes, just 

 as, on the other hånd, several of the species wanting at the Færoes 

 may most likely be found at this part of Iceland, especially perhaps 

 at the Vestmanoer. Some of the latter however can hardly be con- 

 sidered to occur there, as for instance some of the most important: 

 Porphyra leiicosticta, CallophyUis laciniata with Callocolax neglectiis, 

 Lomentaria articiilata, NitophyUiim laceratiim, Polysiphonia violacea 

 and P. Brodiæi, Griffithsia setacea, Cladosteplms spongiosiis, Punctaria 

 latifolia, Himanthalia lorea, Halidrys siliqiiosa, Bryopsis plumosa, 

 Valonia ovalis etc. The algæ-flora of South-Iceland must be regarded 

 as a poorer selection of the Færoese algæ-flora, particularly as some 

 of the warm-boreal species, found at the Færoes, are wanting there. 



When we turn to North-East Iceland, we see that the dif- 

 ference between the algæ-flora there and that at the Færoes is much 

 greater, as might well be expected. From North- and East-Iceland 

 proper, that is, if we count from the head of Huna-Floi to Lons- 

 heiSi on the south-east coast of Iceland, we have 92 red and brown 

 species and 34 green and bluish-green; east of Hornbjarg along the 

 adjacent north-western coast, we have moreover 8 brown and red 

 algæ, and 9 green and bluish-green species, namely: Chantransia 

 microscopica , Cystoclonium purpiirascens , Polysiphonia nigrescens, 

 ■^'Ralfsia ovata, Ascocyclus islandicus, ^Leptonema fasciculatum, "Spha- 

 celaria hritannica, Leathesia difformis, '''Chlorochytrium dermatocolax, 

 Codiohim pusillum, Enteromorpha aureola, "Ulva Lactuca, "Ochlo- 



