26m
L E C I D E A incompta.
Loose mealy-crusted Letidea.
CR YPTOGAMIA Lichenes.
Gen. Char. Patellulce sessile or more or less immersed,
with a margin of a substance different
from the thallus.
Spec. Char. Crust indeterminate, coairsely mealy,
uneven, olive green. Patellulas superficial, small,
purplish black; disk at length convex; margin
narrow, flexuose.
W e find no description agreeing with this Lichen. It
forms large patches on shaded parts of the rugged trunks of
old elms at Shermanbury and Hurst Pierpoint, Sussex.
Thallus spreading widely and irregularly, composed of
coarse particles appearing almost like minute crenate scales
under a moderate magnifier, forming an uneven crust varying
in thickness, and for the most part of loose texture, but
occasionally more coherent and somewhat tartareous; its
hue a dark olive green, which changes in long dried specimens
to a dull ash-colour, and is then but imperfectly recoverable
by moistening. Patellulae numerous, of a dull black, with
a tinge of purple most perceptible when they are wet, flat-
tish when most regular, with a narrow, slightly raised,
waved margin, but often confluent in little clusters, convex,
rugged, and variously deformed; their internal substance
of the same hue as the surface : they are often partially covered
with particles from the thallus.
These patellul® bear much resemblance to those of