Dr. SwrTu's Remarks, &c. II 
No. 176. L. marmoreus. p. 178. 
This plant being unknown to me, I fhall not prefume to make 
any farther remarks upon it, than to obferve in general, that a 
red or purple colour is often not natural to cruftaceous Lichens, 
but occafioned by the urine of fome animal falling upon them, 
to which I fufpeét the colour of Lichen Oederi to be owing. 
No. 177. L. corallinus. p. 180. 
This appears by the defcription to be the true Linnean plant, 
although the-author has not noticed the foliaceous margin fo re- 
markable in this fpecies, by which it is proved to belong to the 
cruftaceous Lichens, and which no writer has yet remarked. The 
figure is very bad, and reprefents an imbricated Lichen. 
No. 178. L. gertufus. p. 181. 
The plant here figured and deícribed is the L. /crupo/us of 
Schreber and Dickfon, totally different from pertu/us in all its ftates: 
indeed the figure is more like.a variety of L. parel/us which 1 have 
often found at Edinburgh, very diftinét from both the above. 
No. 179. L. cinereus. p. 183. 
This is a fpecies about which I could. never fatisfy myfelf. If this 
figure be right, it is a valuable acquifition to botany; but 1 am in- 
clined to doubt it, becaufe it more refembles ater of Hudfon, and 
Linnzus deícribes the margin of his Lichen cinereus as black. 
No. 180. Lichen albo-cærulefcens. p. 184. 
This beautiful Lichen is probably new, if fufficiently diftin& 
from L. immerfus of Weber. 
C 2 No. 
