V. THE VERTICAL DISTRIBUTION 
OF THE LICHENS. 
horoddsen, in vol. I of this work, has given an account of the 
little which is, as yet, known as regards the vertical distribution 
of the phanerogams. It must unfortunately be admitted, that our 
knowledge of the lichens is, in this respect, still more scanty. The 
object which it was desirable to attain, viz., a thorough knowledge 
of the occurrence of each single species, from sea-level upwards on 
the mountains, is still unattained, but something is known on the 
subject. 
It is not known with certainty, as regards any single species, 
how far it has any other upper limit on the mountains, than the 
snow-line, with the sole exception of the decidedly maritime species 
Verrucaria maura and Lichina confinis, which are connected only 
with localities washed by the spray of the waves. 
Nor is it known with any certainty as regards a single species, 
how far it has any other lower limit than the sea-level; several 
species are, however, known, regarding which it is, at any rate, 
probable that they are associated with cold mountain heights, and 
avoid the milder climate of the low land. This is the case, for in- 
stance, with Usnea melaxantha and Solorina crocea, which hardly 
ever descend anywhere into the lowlands, without its being possible 
to give a tolerably definite lower limit. 
In order, however, to give a small contribution to our knowledge 
regarding this point, I shall proceed to enumerate the lichens found 
in a few localities situated on high ground: — 
On Hlidarfjall, which is mentioned under the rock-lichen-asso- 
ciations, under “Liparite,” there grows a scanty vegetation consisting 
of the following species: — 
Rhizocarpon geographicum. Gyrophora cylindrica. 
Lecanora polytropa. — arctica. 
— alpina. = hyperborea. 
Gyrophora erosa. Parmelia lanata. 
