THE BRYOPHYTA OF ICELAND 573 



gether with some other Bryophyta. Hypnum reuoluens, H. ex- 

 annulatum , H. stramineum , H, stellatum, Acrocladinm caspidatum, 

 Scapania irrigua, Pellia Neesiana and Alicnlaria scalaris were very 

 common, Aneura maltifida occurred here and there, especially in 

 the Sphagnum rubellum cushions. Where the ground was less 

 damp, especially on slightly inclined slopes stretching down towards 

 the hot water, it was covered with a thick carpet of Hypnnm im- 

 ponens, H. molhiscnm , H. stramineum , H. revolvens , Hylocomium 

 sqiiarrosum, H. parietinum, //, proliferum and Camptothecium lutes- 

 cens, in which were scattered cushions of Sphagnum, especially S. 

 rubellum and S. teres. Sometimes Preissia commutata also could 

 form bluish-green patches, about a metre in breadth, usually inter- 

 mixed with some Hypnnm molluscum. 



Sturlurrey kja hver is situated on a slightly inclined slope 

 stretching down towards the river Reykjadalsa. At the top, near 

 the spring, there is the usual Sphagnum vegetation which, farther 

 downwards where the ground on both sides of the outlet of the 

 spring is rather boggy, is replaced by a greatly mixed vegetation, 

 composed principally of Hypiuim imponens, Hylocomium sqiiarrosum, 

 Polytrichum gracile, Dicranum scoparium var. orthophyllum, Caly- 

 pogeia Trichomanis and Alicularia scalaris. Alternating with the 

 Hypnum carpet, extensive, dark-green mats of Archidium are found. 

 The surface temperature of the ground under the Sphagnum carpet 

 was, as a rule, 40, whilst under the Hypnum- Archidium carpet 

 there was an almost constant temperature of 37. On stones in 

 the tepid water, the temperature of which was at this spot 34, 

 grew large cushions of Dicranella squarrosa. 



Kleppjarnsreykir is undoubtedly the same spring that 

 Gronlund (1877, p. 350) calls Kleppholtsreykir. He states that at 

 this spring the same two species of Sphagnum occur that are found 

 near Tiinguhver, and that near the spring and its outlet, among 

 others, "Distichium capillaceum, Mnium serratum, Hypnum ochraceum 

 and Catoscopium nigritum" are found. The two last-mentioned have 

 been wrongly determined, and the two first do not at any rate be- 

 long to the species characteristic of the warm ground. 



The outlet has for a tolerably long distance steep banks, about 

 half a metre high, which are, at the foot, covered with the usual 

 liverwort-vegetation: Haplozia crenulata, Fossombronia, Anthoceros, 

 Alicularia and Archidium. The uppermost part is covered with a 

 dense moss-carpet consisting of Hylocomium sqiiarrosum, H. proli- 



