194 OI.AF GALL0E 



As examples of lichen-vegetation in grass-carpets, I shall men- 

 tion a fe\v observations which are typical : 



On sloping ground on the sides of Reydarfjorflur (East Iceland) 

 heaths and grass-carpets grow mixed with one another. The latter, 

 seen from a distance, have a light greyish-green colour and consist 

 mainly of Festnca ovinn mixed with a small amount of C.allnna, 

 Empdrnm, Dryas. Silene acanlis, Cassiope hypnmdes, Betula nana, 

 some mosses and Lycopodium. When I visited the place the grass 

 was very short (36 centimetres), being closely grazed by sheep 

 whose dung was found everywhere. Here and there was an ex- 

 tremely small number of lichens, which played a very subordinate 

 part both as regards abundance and degree of frequency. 



The degree of frequency was determined neither here nor in 

 any other of the grass-carpets investigated by me, because the 

 lichens were so exceedingly unevenly distributed that, in order to 

 obtain a fairly reliable frequency-number, a far larger number of 

 sample-areas would be required, than I had time to investigate. 



The following species were found : 



Stereocaulon coralloides. Cladonia fimbriata. 



tomentosum f. cam- Thamnolia vermicularis. 



pestre. Cetraria aculeata. 



incrustatum. Peltigera canina. 

 Cladonia pityrea. aphtosa. 



uncialis. Bacidia flavo-virescens. 



In quite similar localities, and in an exactly similar vegetation, 

 I found near Seydisfjordur the same scanty lichen-vegetation sup- 

 plemented by a few other species, viz. 



Psoroma hypnorum. 

 Dermatocarpon hepaticum. 

 Collcma spp. 



I found on extensive, very knolly grassland, on mountain-slopes 

 on each side of Eyjafjorikir, a somewhat different vegetation, in that 

 the top of the knolls bore Dryas, Betnla nana or Empetrnm an 

 indication of heath-vegetation. Upon these dwarf-shrubs and the 

 dead portions of the grass-tufts on the top of the knolls, occurred 

 masses of Lccanora tarlarca, and here and there a solitary Cetraria 

 aculeata. The former crustaceous lichen is, as is well-known, ex- 

 tremely common on the stunted plant-carpets of the Arctic regions, 

 for instance in Lapland and Greenland. 



I found near Eyjafjor5ur, just below the summit of Sulur- 



