a p 
d x 
dE: 
284 Lichenes of New | 
confusion in the synonymy of the common forms, 
» owing, probably, to their considerable resemblance 
to each othef. In mentioning the following species, 
I have followed the met of the Methodus 
of Acharius. 
Y faginea, e iieit. Ach. ) Ach. Meth. De * 
N Cand. ke Hook. l. c. — Bark, less common, perhaps; 
than the S This is the V. amara of one of the 
later works of Acharius, and of our authors, and is 
sensibly distinguished from the other species allied 
to it by the bitter flavor of the thallus. This is 
caused by the presence of oxalic acid, detected in it 
by Mr. Braconnot, in the proportion of 29.40f oxalic 
acid, combined with 18 of lime, in 100 parts of the 
lichen. (Hook. 1. c.) 
`- V. discoidea, Pers. (eit Ach. ) Hook. I. c. — reco 
and old rails, very common. < " 
V. aspergilla, Ah. Lich. Univ., Hook. Lc. — Old 
walls, rocks, and trees. 
V. velata, Ach. Syn. (cit. Hook.), Hals... c., Mass. 
Catal. — On trees, common in New England. The 
apothecia greatly resemble the scutelle of a Leca- 
nora, and the species (according to Hooker, l. c.) is 
referred to that voom TA Turner and Borrer. - 
= 
ec 
b Uio scruposa. ‘Since the publication of 
. my former paper, I have observed this plant quite 
common on old walls and in similar situations. Mr. , 
. . Russell has sent it from Chelmsford, where. he finds — ^ 
it abundant, on rocks. At the Cambridge station, it 
occurred on the ground, in a sandy soil. 
U. cinerea, Ach., — forma varians. — Alpine rocks, 
