164 OLAF GALL@E 
continuous, almost pure growths on rocks (Ramalina-belt) on the 
cliffs of Bornholm. Species of Roccella appear to form similar carpets « 
on the cliffs of the sub-tropical and perhaps tropical regions. 
Of Fruticose rock-lichens the following are found in Iceland: — 
Alectoria ochroleuca. Sphærophorus coralloides (?). 
Coenogonium ebeneum. — fragilis (?). 
Ephebe pubescens. Stereocaulon coralloides (?). 
Lichina confinis. = denudatum. 
Racodium rupestre. — evolutum. 
Ramalina scopulorum. Usnea melaxantha. 
== subfarinacea. 
With regard to these it should be remarked that it is some- 
what doubtful how far Racodium and Coenogonium should, on the « 
whole, be reckoned among the fruticose lichens; they have a thread- 
shaped, somewhat procumbent-ascending thallus. Also a query has 
been placed against several of the other species, to indicate that it is 
doubtful whether they are true rock-lichens occurring on bare rock 
because, at any rate when older, they are rarely, in fact very rarely, « 
attached to the rocky substratum. 
5. SYNOPSIS OF THE CHIEF BIOLOGICAL CONDITIONS 
OF THE LICHENS OF ICELAND. 
| 2 Fe Ste | RS | Thallus 
RCE Pme 
Names 2882| = 215 s |2 3] 2 | 2 = 
KER ES ER KOR ERE 202122 
die | © | 8 | ANSE 
Es [= le ERE als 
I 
| | I | | 
Acarospora discreta ............. | | | + | + | | — 
— Fuscatan sa een | | | + IE | | + 
— HEP AS amener | Lam | =) T 
Alectoria divergens.............. | | + | ı | | + 
DAAE TE ae | + + 
== Digricans Le SL Een seele | | + + 
— ochrolenca 405 sie sas de | | + | ie + 
Arthonia proximella............. +. | + | | + 
— puanetiformis we. 20.0, Pas | + + 
— rideralis vastes | | + +. + 
Arthopyrenia analepta........... | + | + + | 
— ere CCE PS cate teh ans cogs is | + | LSE + 
Bacidia abbrevians.............. +) +) 4 
