470 A. HESSELBO 



Hafnarfjordur (Grl.)!; Geithals!. S. Iceland: Skalholt!; Thingvellir!; 

 Breidabolstadr! ; Vestmannaey !. 



Frequent in the western and south-western parts of the country 

 from Borgarfjordur southwards, rarer in the other parts. It chiefly 

 occurs in humus-filled rock-fissures and in lava caves, but also upon damp 

 rocks by waterfalls, in small reddish tufts, or mixed with other mosses 

 such as Plagiothecinm pulchellum, Mnium orthorrhynchum, Pohlia crada, 

 Myurella apiculata, M. julacea, Blepharostoma trichophyllum, etc. It does 

 not appear to ascend higher than about 300 metres above sea-level. 

 Fruit has been found only in Almannagja and very scarcely; ^ plants 

 are rather common. 



119. Plagiobryum demissum (H. et H.) Lindb. 



W. Iceland: Modruvellir in Esja!. 



It was growing here in company with Anomobryiim filiforme on a 

 stony slope at an altitude of about 200 metres. The fruit was ripe on 

 July 17th. but the lids had not yet been thrown off. 



120. Pohlia acuminate. Hornsch. 



W. Iceland: Geitabergsvatn!. S. Iceland: Seljaland!, 250 metres above 

 sea-level; Thingvallahraun near Tintron!; Almannagja!. 



This species grows on dry stony ground in birch coppices or on 

 rock-ledges. Thus on Thingvallahraun it grew on small slopes in the 

 birch coppice in company with Pohlia mitans and Heterocladium squar- 

 rosiilnm. Near Geitabergsvatn, also, it grew on the ground in the coppice 

 in unmixed tufts, 5 10 mm. high, with setse, 10 15 mm. long. On 

 July 20th the capsules were ripe, dark brown, with lids low and conical, 

 muticous. 



121. Pohlia polymorpha H. et H. 



W. Iceland: Modruvellir in Esja!. 



It was growing in the above locality on a tuff-slope at an altitude 

 of about 400 metres. 



122. Pohlia cruda (L.) Lindb. 



Very common. 



This is one of the most commonly occurring mosses, and is of 

 almost equal frequency at all altitudes. It usually grows in rock-clefts 

 filled with soil and on soil-covered ledges, but is also met with both 

 on rather dry and on damp ground, as for instance on knolls in bogs. 



The fruit, which is very frequent, ripens in the first half of August. 



