/ 6 5" [ 1733 ]
CRYPTOGAMIA Algae.
G en. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust greenish-grey, formedof globular
granulations, with a radiated, marginal fringe.
Shields sessile, flattish, glaucous-black, with a
thick, elevated, smooth margin, of the substance
of the crust.
A b o u t as common on the South-Downs of Sussex as our
LichenJihrosTis, t. 1 7 3 2 , according to the observations of M r .
W. Borrer, from whom alone we have received it.
The crust runs over the smooth surfaces of flints, and is in
itself extremely thin, of a greenish grey hue, terminating in a
more or less distinct, fibrous radiating border. But the whole
surface of this crust is nearly covered with small, round, hard,
paler granulations or warts, close, but not very much crowded,
as the darker basis of the crust is every where visible between
them. Such of these warts as are more marginal, and of recent
date, are perfectly globular, and prettily scattered oyer
the fibres of the border. Internally they are all white. Among
the older warts, but not proceeding from them, grow several
scattered sessile shields, larger than the warts, whose disk is
concave when young, nearly flat when old, blackish with a
glaucous tinge; their margin elevated, thick, smooth, though
rather irregular, of the same substance and colour as the warts.
In the system of Professor Acharius this would come into
the genus Parmelia.---------From an imperfect specimen on
quartz sent by b'tn we think he may have confounded this
species with his Lecidea dendritica, which could happen only
from his never having seen the shields.
2733
A p r. i. ifb ;. 27ib//.f2il? b y ,/a :r ,?(nrerb\’ London .