798 



The 104 Færoese species which have not been found at North- 

 East Iceland are divided into the foUowing groups: 



The sul)arctic group: Chantransia efftorescens, Ch. uirgatiila, 

 Hfirneijella mirahilis, Sordpion Kjellmani, Perciiisaria perciirsa, Pilinia 

 marilima. Vivella con fluens, Pringsheimia scutata, Spongomorpha ver- 

 nalia. All these 9 species will most likely be lound at North-East 

 Iceland. 



The boreal-arctic group: Polysiphonia elongata and Rivularia 

 atra, both of which will certainly also be found at North- East Iceland. 



The cold-boreal group includes the great majority, namely, 

 66 species, but I need not mention themhere; some of them may 

 perhaps be found at North East Iceland, but most of them pro- 

 bably not. 



Lastly, the warm-boreal group includes 27 species, none of 

 which probably are to be found on the coasts of North-East Iceland. 



If we now pass on to Greenland, we find, according to Ro- 

 senvinge (71, p. 166 — 172), that the total number of species is 167, 

 when the algæ-flora of both West and East Greenland is included. 

 To this number must be added Actinococcus snbculanens which 

 Rose uvinge did not accept as a species, according to Darbi- 

 shire's view at that time. According to Jonsson (42), we must 

 further add 7 species, firstly Microsyphar Polysiphoniæ; tlien Ro- 

 se n vin ge's Spongomorpha arcta includes Acrosiphonia inciirua, 

 A. hystriæ and A. penicilli formis; also 3 species of Ulothrix must 

 be added : U. psendoflacca, U. scutata and U. subflaccida, whilst U. 

 consociata is partly the same as Rosen vin ge's U. implexa. Lastly, 

 Rosenvinge's Sphacelaria olivacea includes Sphacelaria radicans 

 and Sph. britannica. Thus the number of species we know from 

 Greenland becomes 176. According to my judgment of the species, 

 Enteromorpha prolifera must, however, be withdrawn, and accor- 

 ding to Foslie's latest views the 12 species of Lithothamnion men- 

 tioned by Rosen vinge must be reduced to 6^; the total number 

 of species thus becomes 169. At the Færoes we meet with 104 of 

 these species. The Færoes have 108 species (-+- 3 only determined 

 as to the genus) that are not found at Greenland, but on the other 

 hånd, we find 65 species there that do not grow at the Færoes; 

 thus 49*^/0 of the 212 Færoese algæ are common to both countries. 



^ Lithothamnion botrijoides, L. ftahellatum, L. colliciilosiini and L. varians 

 bejng rcferred to L. glaciale, and L. circuniscriptum to L. compactnni. L. innestiens 

 is doubtful at Greenland and L. fri.ticiilosiim is the same as L. intermedium. 



