close sponge-like down, paler and yellowish towards the
extremities, and approaching to black in the central parts
ofthe thallus. Cyphellae numerous, small, roundish, white
or pale brown, and empty, but of a rather powdery appearance,
within ; their margin thin, entire or a little lacerated,
more or less indexed, projecting to the surface of the spongy
fibres, and inclosing a proper interior membrane, which is
not however always perceptible. Scutellae some scattered,
some clustered near the edges chiefly about the sinuses of
the thallus. They first appear as brown immersed points,
gradually rising and expanding with a concave, then flat,
and at length convex, reddish brown or liver-coloured disk,
pale internally, and a blunt, waved, often rugged or somewhat
downy margin, formed from the thallus, sometimes
paler than the disk, sometimes of the same or even a darker
hue. The fully-formed scutellae are about equal to hemp-
seed in diameter, appressed to the thallus, but connected by
their central part only; their underside more or less shaggy.
In some of them a small central, prominent, concave pimple
occurs, of a texture resembling that of the margin, as if
the scutellae were becoming compound. The plant has the
fetid odour common to other species of Sticta.
The species figured at tab. 1103, 1104, 2110, 2298, 2359,
and less decidedly those at 497, 572, belong to this group.
It seems a natural genus, but its fructification affords no
good technical character, unless the remarkable appearances
on the underside of the thallus, presumed to be a sort of
“ accessory apothecia,” be regarded as sufficient. These
vary much in their nature. In a few species they are merely
irregular bald spots, apparently proceeding from abrasion
of that surface; in others they are powdery warts, soredia,
without a margin ; and again in others, as in the species
now before us, little pits, cyphellce, furnished with a margin
from the superficial membrane of the thallus, within which
they are originally formed: these cyphellae also vary, being
in some species filled with a powdery substance, in others
empty, or merely lined with powder.—Parmelia glomulifera,
although closely connected to the other Parmelice by P .
Icete-virens and P. tiliacea, wants only one or other of these
appearances to make it a Sticta. In the substance- colour,
and divisions of its thallus it approaches S. macrophylla;
and we have a specimen of a similar Lichen, gathered by
Mr. Wiles in Jamaica, which bears at once the cyphellae of
the Sticta, and branched tufts like those of the Parmelia.
S. macrophylla is very nearly allied to S. damcBCornis ; but
the segments ofthe thallus of the latter, although they vary
considerably in width, seem to be always more linear and
more concave. It may be doubted to which of these two
species Hoffm. PI. Lich. t. 24. ƒ 7, taken from a specimen
from the Isle of Bourbon, should rightly be referred. How
far .§. laciniata is really different we have not the means of
ascertaining, for want of authentic specimens. Both the
descriptions and Hoffmann’s figure lead us to suppose it at
least very nearly allied to our S. macrophylla.— IV.B.