THE BRYOPHYTA OF ICELAND 551 



glacialis, Brijiim Diwalii, Chiloscijphus pohjanthns var. frcKjilis, Harpan- 

 thus Flotowianns and Pellia Neesiana. 



7. Kaldalon, along Ihe banks of a stream : Hijpnum calli- 

 chroiim, Sphagnum teres, Harpanthus Flotowianns and Cephalozia 

 hicnspidata var. Lammersiana. 



8. Reykjavik, on ground over whicli water was tlowing: 

 slightly inclined surface ^vilh sireandets. The hanks of the streamlets 

 were fringed with Philonotis fontana, Mnibri/nni albicans var. (jla- 

 cialis, Brijnm uentricosnm, li. Dnvalii and Acrocladinm cuspidatnm. 



9. Gnupsdalur (NW. Iceland), gravelly ground, over Avhich 

 water was flowing, streandets llowing down the sides of the valley: 

 Philonotis seriata , P. fontana , Dicranella sqnarrosa, Haplozia cordi- 

 folia, Chiloscyphns polijaiilhns var. fragilis, Scapania undnlala and 

 S. palndosa. Haplozia fornied large black or greenish-hlack, and 

 Scapania palndosa very large reddish-brown patches in the water, 

 which was a few centinietres deep. 



In North Iceland several species oi^ Hypnnin occurred abundantly 

 in gravelly soil over which water was flowing, and often formed pure 

 Hypneta. Especially do Hypnnm e.vannulatnm var. pnrpnrascens. 

 H. falcatnm, H. decipiens and sometimes H. straminenm and H. sar- 

 mentosnm occur in such localities. 



The Bryophyte Vegetation on Muddy Soil near Springs (D.\). 



The bright-green moss-carpet around and below the point of 

 issue of the springs described by Helgi Jonsson (1900, p. 24; 

 1895, p. 73) as moss bogs (Icelandic D>) are one of the most 

 frequently occurring and characterislic plant communities of the 

 Arctic and Sub-arctic regions. Thev were first mentioned bv Gron- 

 lund (1877, p. 330) as mats of sapgreen mosses along small streams 

 on mountain sides, consisting of Bartramia fontana, Webera albi- 

 cans, Brachythecinm rntabnlnm var. rivnlare and Hypnnm nncina- 

 tum , a description which includes both the moss bogs and the 

 moss vegetation along smaller streams, which have also much in 

 common. 



Moss bogs develop in muddy soil, in all piaces where the 

 ground water emerges as springs. They occur both on mountain 

 slopes and at the botlom of valleys , occasionally also at higher 

 levels, on rocky Hats, but they are especially numerous on the 

 lowest mountain slopes and in the flat boggy land below these 



