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In order to convey a more diftindt Idea of the fe- 
veral plants of this genus, which enter into oecono- 
mical or medical ufes in the various parts of the 
world, we dial l diftribute them into feveral orders, 
according to the cuftom of former writers : and as 
is not confident with our plan to defcribe each of 
thele f h ecies, we fhall refer to the page of the more 
modern authors, where they may be found. 
i. Lichenes filamentofi. 
Such as confijl of mere f olid filaments , of a firm 
and folid but flexible texture , having the appear - 
ance of fructification in the form 0/ fcutellae, or 
fiat round bodies growing from the fides or ex- 
tremities of thefe filaments. 
This order or divifion comprehends the hairy tree- 
modes, or ufnea of Dillenius and Hill ; feveral of 
the fpecies of the fifth order of lichens of Micheli ; 
and the lichenes filamentofi of Linnaeus. 
Dr. Dillenius defcribes lixteen fpecies under the 
term ufnea , feveral of which are found in England, 
tho’ fome of them, as the common ufnea of the lhops, 
but very fparingly, and none of them in any con- 
fiderable plenty. The thick woods in many other 
parts of Europe, and the reft of the globe, afford them 
in great plenty. They hang from the branches of 
various kinds of trees, like large tufts of hair, to a 
conliderable length : fome fpecies grow feveral feet 
long. The rocks on the tops of high mountains 
afford feveral kinds. They are of various colours ; 
fome whitifli, afli-coloured, others grey or blackifh, 
and two or three fpecies have a yellow or orange hue. 
The 
