THE BRYOPHYTA OF ICELAND 579 



Bryophyta appeared first at the edge of the outlet of the spring where 

 the temperature ^vas 25°— 40°. The vegetation here resembled that 

 of wet, cold ground, and was usually composed of Philonotis fon- 

 tana, Mniiim Seligeri, Hypniim straminenm , Catoscnpium nigritum, 

 and in a single spot of some Sphagnum angustifoUum. On drier, 

 warnier ground Hijpnnm imponens was found here and there in 

 Company with Hijpnum straminenm, Hylocomiiim sqnarrosum, Archi- 

 dinm phascoides, etc. 



Of the hot springs situated at higher levels only a few have 

 been investigated. In the neighbourhood of Kolvidarhol, al an 

 altitude of about 350 metres, on the warm ground around some 

 holes whence issued vapours impregnated with sulphurelled hy- 

 drogen and where sulphur had been deposited, the following species 

 were growing: Ggmnocolea inftata, Haplozia crennlata, Fossombronia 

 Dnmortieri, Aneura pinguis, Archidium phascoides and Polytrichnm 

 commnne. Here Gymnocotea inflata was not strictly confmed to the 

 warm ground, but appeared rather to prefer clay, as it also grew 

 on clayey flåts which had probably been warm previously, but were 

 now quite cold. 



The same species together with Blasia pusilla grew also in Rey- 

 kjadalur (at an altitude of about 260 metres) on the damp base of 

 a warm slope from which vapours, containing sulphuretted hydrogen, 

 and water issued sparsely from numerous small holes. Near some 

 mud-pools on Hellisheidi only Gymnocotea inflata and Haplozia 

 crennlata occurred. 



The Sulphur Springs on Reykjanes — which I myself had no 

 opportunity of visiting — have been described by Ostenfeld (Bot. 

 Tids., vol. 22, p. 239). They occur in two groups, near Reykjanes 

 lighthouse and also near Krisuvik. 



The Sol fa taras near Reykjanes lighthouse form a large 

 group with numerous orifices of discharge, partly mud-pools, partly 

 steaming holes, everywhere around which the ground is warm 

 (20° — 30°). Near the outlet of the largest mud-pool, Gunna, the 

 damp ground, which had a temperature of about 30°, was covered 

 with Haplozia crennlata to which, along the margin, came several 

 other species, viz. Fossombronia Dnmortieri, Archidium phascoides 

 (recorded by Ostenfeld as Pohlia nutansx. filicautis), Trichostomum 

 littorale and Bryum ventricosum, all of which, however, only occur- 

 red sparingh'. Around the steaming holes grew Riccia bifurca, 

 Preissia commutata, Fossombronia Dumortieri, Archidium phascoides, 



