470 A. HESSELBO 



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

 Breidabolstadr! ; Vestmannaeyl. 



Frequent in the western and south-western parts ol" the countrj^ 

 from Borgarfjordur southwards, rarer in the other parts. It chietl^' 

 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 Plagiotheciiim palchclliiin., Mniiim urtJiorrhynchiim, Pohlia cruda, 

 Mijiiri'lla apiciilata, M. jiilacca, Blepharostoma trichophyllum, etc. It does 

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

 Fruit has been found only in Almannagjå and verj' scarcel}'; ^ piants 

 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 attitude of about 200 metres. The fruit was ripe on 

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



120. Pohlia acuminata Hornsch. 



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

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



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 imtuiis and Heterocladiiim sqiiar- 

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

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

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

 muticous. 



121. Pohlia polymorpha H. et H. 



^Y. Iceland: Modruvellir in Esja!. 



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

 of about 400 metres. 



122. Pohlia cruda (L.) Lindb. 



Ve ry common. 



This is one of the most commonh' occurring mosses, and is of 

 alraost 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 knolis in bogs. 



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



