186 OLAF GALLOE 
tion to heath-vegetation. An instance of this is also given below 
under the description of heaths (Type III). 
We shall elsewhere — under the description of Iceland’s moss- 
carpets and their lichens, — have an opportunity of discussing the 
competition between moss and lichen. Here it will suffice to state, 
that lichens, in the loose soil of mountain-hights, in mountain- 
deserts, rarely occur on quite bare, purely inorganic soil. They 
show a peculiar tendency to seek company with mosses or other 
plants, without its being always possible to state precisely, which 
have been the first to arrive on the spot. 
The species which appear to be most common on loose soil 
in mountain-deserts are the following: — 
Cladonia turgida (fruticose lichen), frequently sterile. 
— pyxidata — — , on humus. 
— rangiferina — — 
== coccifera — — 
Stereocaulon denudatum — — 
Alectoria nigricans — — 
Thamnolia vermicularis — , sterile. 
Cetraria hiascens (foliaceous lichen), frequently sterile. 
— islandica — — 
— Fahlunensis = — 
— aculeata (fruticose lichen), — 
Solorina crocea (foliaceous lichen), — 
Pannaria microphylla — 
Peltigera aphtosa == = 
= lepidophora — = 
Dermatocarpon hepaticum — , on moor-soil. 
Lecanora tartarea (crustaceous lichen), fertile; on moss, moor-soil 
and lichens. 
Bacidia flavovirescens (crustaceous lichen), often sterile; on purely 
inorganic soil. 
Pertusaria oculata (crustaceous lichen), often fertile. 
Buellia parasema = 
v. papillata, fertile; on moor-soil. 
v. triphragmia, fertile. 
Rinodina mniaræa (crustaceous lichen) 
v. cinnamomea, fertile; on moor-soil. 
Lecidea assimilata (crustaceous lichen), fertile; on dead moss. 
Caloplaca Jungermanniæ = , fertile; on moor-soil. 
Psoroma hypnorum = , fertile; on moss. 
Lecanora castanea — , fertile; on moor-soil. 
Bæomyces byssoides — , often sterile; on moor-soil 
rich in mineral. 
