[ ^73 ] 
4* Lichenes cruftacei. 
Such as conflft of a dry and friable matter, more 
or lefs thick , formed into flat crufts, very clofely 
adhering to whatever they grow upon . 
Some of the fpecies of this divifion confift of an 
exceeding fine thin cruftaceous, or rather, as Micheli 
calls it, farinaceous matter, the fructifications appear- 
ing in the form of tubercles. Others confift of a 
thicker fcabrous cruft, having the fructifications in 
the form of little cups, called f cut elite. 
This divifion contains the firft order of the liche - 
noides of Dillenius ; the fth, 6th, and 7th orders of 
Haller’s lichens j the lichenes leprofl and crujlacei of 
Linnaeus j and feveral of the placodium of Hill. 
The fpecies are numerous, and moft of them very 
common on rocks, ftones, old walls, the bark of 
trees, old pales, &c. which are commonly covered 
over with them, in undifturbed places. They form 
a very agreeable variety, and fome of them have a 
very elegant appearance. 
Dr. Dillenius deferibes a fpecies of this order, 
which he found upon the tops of .the mountains in 
Caernarvonftfire in Wales ; and which the inhabit- 
ants told him they ufed as a red dye, and found it 
preferable to the cork, or arcel, which they call ken- 
kerig. He has intitled it, in Englifh, The white tar- 
tar eous Jcar let- dying lichenoides (14). He is of opi- 
(14) Lichenoides tartar eum tinftorium candidum tubtrculis atris. 
Hift. Mufc. p. 128, 
Vol. 50. 4 R nion, 
