The English flora - SeaweedAfrica

Spiloma.] I.1CHENES. 165
the extreme minuteness of the parts prevent its being detected;
and which, in one individual (S. gregarium) actually rises above
the surface of the thallus, and is often found quite bare, forming
what appears a very conspicuous apoihecium"
1. S. microsedpicum, Turn, and Borr. (microscopic Spiloma);
crust spreading widely filmy very thin greyish, apothecia extremely
minute black lead-coloured when dry. Turn, and Borr.
Lick. Br. p. 30. E. Bot. t. 2396.
Common on boarded buildings, &c— " Thallus or crust a most obscure
grey film, spreading indeterminately and very widely, so thin as merely
to tinge the fibres of the wood on which it grows. Apothecia, (or pul-
vinuli, as they are called by Messrs. Turner and Borrer,) not discernible,
except with a microscope of considerable power. Sporules bluish when
dry, black when wet, readily adhering to the fingers."
2. S. murdle, Turn, and Borr. (wall Spiloma); crust none ?
apothecia extremely minute confluent black. Turn, and Borr.
Lick. Br. p.3\. E. Bot. 1 2397.
On plastered walls of cottages, in the parishes of Hurst-pierpoint and
Albourne, Sussex; and on the walls of Burgh Church, Suffolk.—The
absence of thallus is accounted for by the authors of Lichenographia Br.
by the circumstance of this plant having as yet been detected only on
mortar and coarse-grained stone, on which substances the thallus of other
Lichens is known to grow very thin and sometimes altogether to disappear.
3. S. splmrdle, Ach. (globose parasitic Spiloma); parasitic,
apothecia minute subglobose scabrous black opaque. Ach. Syn.
p. 2.
Upon the crust and podctia of Isidium coralhnum and other Lichens.
—This is enumerated in Mr. Borrer's list of the British species; but
1 am unacquainted with it.
4. S. dispcrsum, Turn, and Borr. (dispersed Spiloma); crust
filmy very thin greyish, apothecia mostly dispersed hemispherical
sooty-black internal lv of a yellowish-green. Turn, and
Borr. Lick Br. p. 32. E. Bot. t.2398.
On old rails, not unfrequetot.—This agrees with 8. microscopic*** in
its obscure filmy thallus, but differs abundantly in the Bize, disposition
and structure of the apothecia. "It is nol unfrequently found intermixed
with it; insomuch that we would by no means be understood S3
speaking with certainty, when we mention its thallus, whether this thal-
lus may not, in reality, belong to the other, and S. ditpmum be alto*
gether destitute of one."
5. S. minitinu. Sin. (golden Spiloma); crust inclining to tartareous
thin white, apotheeia rather eon\.\ al Length eontlueiit
deep brown internally yellow. E. Bot. t. 2078. Turn, and
Borr. Licit. Hi. />. •')•'*. S. tricolor. Ach. Sun. p. 'J.
Common on timber, in old walls, ftc, Busses ; on Elm-bark t ; Portslade:
on the church-walls at Henfield, Sussex* and Wrentham, Suffolk;
and eery line mi ehurehes near Bur\ St. KdinumU.—OfUlisvety
curious and beautiful species, the apothecia are M about the sise ol
poppy-seed, round, more or less convex, soon becoming confluent ami