[ 2540 ] m
L I C H E N plumbosus.
Lead-coloured Dot Lichen.
CRYPTOGAMIA Algce.
Gen. Char. Male, scattered warts.
Female, stnooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust tartareous, minutely cracked and
rugged, lead-coloured, limited. Tubercles half-
immersed, globose, black ; pale within.
Syn. Verrucaria plumbea. Ach. Lichenogr. Umv.
v. 1. 285.
G a t h e r e d by Mr. W. Borrer, on limestone rocks near
Chedder, Somersetshire. To him we are indebted for specimens,
and for the synonym. As there has long been a Lichen plumleus,
we are obliged to make a small change in the specific name, until
our difficulties about the genera Verrucaria and Endocarpon are
removed.
This species differs sufficiently from L. Harrimanni, l. 2539,
not so much in the bluer colour, as in the tessellated configuration
of its crust, which moreover is destitute of impressed dots.
The tubercles also are much larger, sunk only about half their
depth, or a little more, in the crust. We find a distinct orifice
in the centre, though Acharius says it is scarcely ever discernible.