201 



St. rostelhim Roy and Biss., St. horametriim Roy and Biss., Xanthidiiim 

 qiiadricorniitiim Roy and Biss., etc. 



While thus, upon the whole the freshwater algæ of Ihe Færoes 

 must be considered as West European especially English, the 

 Nordreoer -- where also the Arctic-Alpine phanerogams are most 

 richly represented — contain an algæ-flora of a more Arctic stamp. 

 Thus the following Desmids were found in a collection of algæ 

 from Bordo gathered by Ostenfeld at a height of 450 metres: — 

 Cosmarinm anceps Lund., C. coelatiim Ralfs, C. ciiciimis Ralfs formå 

 major Nordst., C. Holmiense Lund. § integriim Lund. formå (Nordst. 

 Desm. Spetsb. p. 28, tab. 6, fig. 5), C. homalodernmm Nordst., C. latum 

 Breb, C. microsphinctiim Nordst. § crispnhim Nordst., C. speciosiim 

 Lund. var. biforme Nordst., C. snbspeciosiim Nordst., Staiirastnim 

 acarides Nordst. (abundantly !), 5/. Meriani Reinsch, Penium cras- 

 siiisculum De Bar. As will be seen from this list, all the Desmids 

 — barring a few exceptions — are such as have been described 

 from and are common in the Arctic regions, and the absence of 

 some species, common to low-lying regions, further proves the 

 Arctic character of the above gathering, thus, the large species of 

 Euastriim are wanting, and regarding them Boldt writes^ that they 

 are »conspicuous by their absence in the northernmost countries«. 



It is also here in the northernmost part of the Færoes that 

 Hijdriiriis penicillatiis occurs, as it has been found by Lyngbye on 

 Slattaratinde, the highest mountain in the Færoes, True, this alga 

 is common in Central Europe early in spring when the snow 

 melts, but it is also common in the Arctic regions. 



If we now ask how the Færoes after the glacial period, at 

 which time we may presume that they were completely covered 

 with ice and snow, have got this comparatively rich freshwater 

 algæ-flora, I can only confirm the statement of Wille in his above- 

 mentioned paper in which he quite abandons the theory of a former 

 belt of land as a means of immigration. Of the four different means 

 of distribution named by Wille, it is mostly — as also Wille points 

 out — the wind and the migratory hirds, and especially the latter, 

 which are of such great importance to the Færoes. In addition to his 

 arguments in favour of this theory I think further proofs are found 

 by the faet of my having met M-ith several Irish and Scottish algæ 

 in the Færoes and partly and not least from the Arctic element of 



' Boldt 1. c. p. 84 »som lyse genom sin fraiivara i de nordligaste landerna . 



