THE BRYOPHYTA OF ICELAND 565 



ground. In North-west Iceland Ihe developmenl of the liverwort- 

 mats was especially typical in niany piaces (for instance in Gnups- 

 dalur and near Isafjordur); they consisted chiefly of Harpanthus 

 Flotowianiis, Aliciilaria ijeoscypha, A. scalaris, Cephalozia bicuspidala 

 var. Lammersiana and Lophozia qiiinquedentata. Here Oligotrichum 

 hercyniciim also occurred abundanllj' in damp sandy localities. 



On a soniewhat damp, cold flat at the bottom of the fjord 

 Kaldalon, below the Jokull, grew Pohlia gracilis, Hypniini eæannu- 

 latiini var. brachydictyon , Philonotis tomentella and Eiicalyx subel- 

 lipticiis. 



The Bryophyte Vegetation near Hot Springs. 



Iceland abounds in hot springs; they are not, however, equally 

 distributed over the whole country, but are most numerous in dis- 

 tricts in which the most volcanic activity occurs. The majority 

 of these hot springs are found in the south-eastern part of the 

 country, on Reykjanes, around Reykjavik, in the south-western low 

 land, and in several of the valleys of West Iceland, especially in 

 Reykholtdalur. In North Iceland, the district around Myvatn is 

 rich in hot springs, but they are also found scattered singly over 

 the whole of this part of the country-. They are absent from East 

 Iceland, but a few occur in North-west Iceland, especially around 

 Isafjardardjup. Groups of hot springs are found in several spots 

 in the inner high land, but the Bryophyte vegetation around these 

 is quite unknown. 



The majority of the hot springs of Iceland have a rather high 

 temperature, the water being most frequently at about boiling point. 

 Springs, the temperature of which is not much higher than that of 

 their surroundings, are found for instance around Isafjardardjup 

 near Laugarbol (50°— 55") and Nauteyri (25 " — 30°), yet no charac- 

 teristic vegetation had developed there. According to T horodds en 

 such springs also occur north of Vatnajokull, and have a tempera- 

 ture which is not many degrees higher than their surroundings. 



The hot springs in Iceland may be classified as belonging to 

 two different groups, viz. the Alkaline Springs and the Sulphur 

 Springs. 



The Alkaline Springs (thermæ) usually occur in districts where 

 there has been no recent volcanic activity. They contain pure, 

 clear water which often deposits siliceous sinter, and are always 

 surrounded by a luxuriant vegetation. When the temperature reaches 



