LICHENOLOGY OF ICELAND 225 
Lecanora atra, crustaceous lichen. 
— badia, — 
— varia, — 
== tartarea, — 
— pallescens, — 
Caloplaca vitellina, == 
— ferruginea v. obscura, — 
Acarospora Heppii, — 
= fuscata, — 
Hæmatomma coccineum, — 
Lecidea elæochroma, — 
— auriculata, — 
— convexa, — 
= panæola, — 
= pantherina, — 
= cinereoatra, — 
Buellia myriocarpa, — 
Rhizocarpon geographicum, — 
Sterile crustaceous lichens, — 
Lepraria, == 
Parmelia saxatilis, foliaceous 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 °/o of the samples. All other plants were absent. 
A Foliaceous-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 
