[ 6 7 6 ] 
which are prefently brought thither by the winds, 
loon cover it all over. Thefe corrupting, prefently 
afford a foil fufficient to nourjfh other fmaller moffes j 
which, in their turn, form one deep enough for 
larger plants and trees ; and thus the rock becomes a 
fertile ifland (21). 
5. Lichenes foliacei fcutellati. 
Such as confift of a more lax and flexible matter , 
formed into a foliaceous appearance , having the 
parts of fructification in the form of fcutellae. 
Some of the plants of this divifion are interfperfed 
with the former in fome of the fyftems of botanic 
authors. In general this divifion contains the whole 
firft feries of the fecond order of lichenoides in Dille- 
nius ; the firfl divifion of the fecond feries, and the 
latter part of the fecond divifion, of the fame : it 
comprehends the lichenes imbricati and umbilicati 
of Linnaeus ; and many of the placodium of Hill. 
The plants of this order are many of them not 
lefs common in England than the foregoing, on 
rocks, ftones, old pales, trees, &c. Some adhere 
very clofely to what they grow upon, and feem to 
be only foliaceous about the edges : others adhere 
but loofely, and are much expanded and divaricated, 
fo as to form fomething like ramifications. 
It was remarked, from Linnaeus’s obfervation, that 
one of the cruftaceous lichens was fcarcely ever found 
growing but upon limeftone^rocks. On the contrary. 
(21) Vide CEconom. Natur. in Amaen. Acad. vol. II. p. 17. 
the 
