404 A. HESSELBO 



Laugardal ,Grl.;l); Reykjanes near hot s|)rings (Ostf.)!; cominon every- 

 where on faccs of tufT rocks in Fljotshlid and below Eyjafjallajokulll. 



Preissia commntata occurs both on more or less damp ground and 

 on damp rocks, and also on warm clayej' flåts near hot springs. In 

 the last situation, as in Rcykholtdalur , it covers large arcas on slopes 

 stretching down towards the boiling hot water. In E. Iceland it has 

 not yet been found: in N. and NW. Iceland it is rather rare and grows 

 thcre on damp rocks, along river-banks or in rock-clefts. In S. and 

 SW. Iceland it is frequent in lava-clefts near Thingvellir and Hafnarfjordur, 

 and in S. Iceland proper it is very common. Thcre it grows at the 

 base of, or some wa}' up the rock faces, cspecially upon those with a 

 Southern exposure, or in sheltered clelts, and oflen occurs in great 

 abundance, and fruiting richly. The fruit was not quite ripe even at 

 the end of Julv. 



9. Marchantia polymorpha L. 



Common all over Iceland on damp soil, on rocks, by rivers, in 

 marshes and in moss bogs, and very often found with fruit or anthc- 

 ridiophores. It is extremely common especially in NW. Iceland, and 

 covers banks of streams often in great abundance, to a height of about 

 300 metres. In S. Iceland it is also very common on damp tufl" rocks. 



This species is niost widely distributed in the birch zone to a 

 height of about 300—400 metres above sea-level where it usually grows 

 on marshy or gravcUy ground along small streams, or occurs in abun- 

 dance in moss bogs or in marshes among mosses. But it is also met 

 with upon mountain heights, as for instance near Berufjordur, Seydis- 

 fjordur and Isafjordur. wherc it has been collected abundantly up to a 

 height of 600—700 melres. 



Fam. ANEUllME. 



10. Aneura pinguis (L.) Dum. 



Riccardia pinynis L.) Gr. 



Very common on damp ground both in marshes and on gravelly 

 soil by rivers and also on damp rocks. It usually grows intermixcd 

 in the tufts of other Bryophyta, rarely forming tufts by itself; it has 

 been collected in fruit in a few localitics only near Eyjafjordur, and 

 near Seljaland at an altitude of about 500 metres\ Il is most widely distri- 

 buted in the lowlands up to about 300 metres, but il is also frequently 

 met with upon mountain heights. 



11. Aneura multifida Lindb.) Dum. 



Riccardia multifida (Lindb.) Lindb. 



E. Iceland: Lon!, on swampy ground among Sphagnum ruhellnm; 

 W. Iceland: Reykholtdall, frequent near hot springs intcrmixed in tlie 



