THE BRYOPHYTA OF ICELAND 



567 



banks of Ihis brook and of the flat boggy surroundings (which are 

 partly influenced by the heat of the soil, partly inundated by the 

 hot water) is very hixuriant. Both aiound the basins of the springs 

 and along Ihe brook formed by the outlets of the springs, grew a 



Fig. 21. Thorlukshver near Skalholt. In the background the river Bruara: behind 

 the fence to the left is a potato field, where the temperature of the ground was about 

 25°. The chief outlet of the spring is just behind the small elevation to the left, and 

 the outlet-channel is from the right straight across the foreground. The "peninsula '. 

 in the middle of the figure, surrounded by the hot water, is partly covered with 

 Sphagnum (the light patch) and partly with Hijpniim-mats (the dark patch). 



broad belt of enormous yellowish brown and pale-green Sphagniim- 

 cushions, 25 cm. deep, chiefly formed by S. imhricatum (yellowish 

 brown), ^S. teres and S. cymbifolium (whitish green) interwoven with 

 Hypniim stramineuin, Hylocomium sqiiarrosiim and here and there with 

 Acrocladiiim cnsjndatum, Hypniim imponens and H. Lindbergii. The 



