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LICHEN elæinus.
Orbicular Olive Lichen *
CRYPTO GAMIA Algde.
G enj C har. Male, scattered warts.
Female, Smooth shields or tubercles, ill which the
seeds are imbedded.
Spec. Char. Imbricated, depressed, stellated, membranous,
dark greenish olive ; smoothish, and of*
the same colour, beneath; its segments close-
pressed, pinnatifid, linear, obtuse. Shields central*
brownish-black, with a border like the crust.
Syni Parmelia elseina. Ach. Meth. Suppl. 4 5 .
T his, as Mr. Borrer observes, is not rare on the barks of
elms and fruit-trees, nor much more so on fliftt Walls. We
are obliged to that gentleman for the specimens here exhibited.
We have for some time remarked the same on walls and trees
about Norwich, but hesitated how to distinguish it from
cycloselis, t. 1942. These specimens, compared with those
of Acharius, and with his description, have at length entirely
satisfied us.
The present Lichen differs from cycloselis in its smaller size,
thinner texture, and blackish olive hue, as well as in being
much more closely pressed to the bark, like a crustaceous
Lichen, and in the almost total want of fibres on its under
side, so that nothing like a fringe is discernible at the edges of
the narrow, linear, abrupt, zigzag segments which compose
the circumference. Pale scattered mealy warts are Seen here
and there towards the middle, and still more in the centre appear
several small shields, with a thick, inflexed, smooth border
of the substance of the leaf, and a flat blackish-brown
disk.