LICHKNOLOGY OF ICELAND 225 



Lecanora atra, crustaceous lichen, 



badia, 

 varia, 

 tartarea, 

 pallescens, 

 Caloplaca vitellina, 



ferruginea v. obscura, 

 Acarospora Heppii, 

 fuscata, 



Haematomma coccineum, 

 Lecidea elasochroma, 

 auriculata, 

 convexa, 

 pana?ola, 

 pantherina, 

 cinereoatra, 

 Buellia myriocarpa, 

 Rhizocarpon geographicum, 

 Sterile crustaceous lichens, 

 Lepraria, 



Parmelia saxatilis, tbliaceous lichen. 

 Ramalina subfarinacea, pendulous fruticose lichen. 

 Stereocaulon denudatum, erect fruticose lichen. 



In a locality, close to the one described above, there occurred 

 on a vertical lava-face a crustaceous-lichen growth, poor in indi- 

 viduals; fruticose and foliaceous lichens were quite absent from it; 

 and all the sample-areas showed bare rocky substratum, whilst not 

 even all of them contained crustaceous lichens, which were found 

 only in 76 % of the samples. All other plants were absent. 



A Foliaceo us-lichen -association was observed by me, for 

 instance near the farm Reykjahlid, near Myvatn (North Iceland). The 

 dominant species were: 



Parmelia saxatilis, foliaceous lichen. 

 Physcia stellaris, 

 Xanthoria lychnea, 



Stereocaulon denudatum, fruticose lichen. 

 Lecanora saxatilis, crustaceous lichen. 

 Caloplaca elegans, 

 vitellina, 

 Lecidea confluens, 



assimilata, 



paupercula, 



pantherina, 



Rhizocarpon geographicum, - 

 geminatum, 



The Botany of Iceland. Vol. II. 15 



