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L I CHE N immerfus.
Sunk Lichen.
, 0) 0;
C R T PTOGA M I A Alga.
Gen. Char. Male, fcattefed warts.
Female, fmooth fhields or tubercles, in which the
feeds are imbedded.
Spec. Char. Shields entirely black, each funk into a
cavity in the hard, whitifli, fmooth cruft, and deciduous.
Syn. Lichen immerfus. With. Bot. Arr. 169.
Relh.Cant. Suppl. I. 23 . Weber FI. Goetting. 188.
Smiths 'Tour, V. 1 . 1 7 1 . Sibth. Oxon. 3 1 8 .
rTT OUND in Derby {hire and other counties at all feafons on
calcareous rocks; we have not obferved it on any other.
The cruft is almoft as hard as the ftone on which it grows
(though very diftinft from it) half- a line, or not fo much, in
thicknefs, nearly entire in the margin, greenifh internally, its
furface white, fmooth, full of little hemifphserical cavities of
various fizes and depths, the bottom of each of which is occupied
by a black deprefled fmooth fhield, with an entire margin
of a more intenfe black than the dilk.
Thefe ftnelds in time fall out, leaving the almoft everlafting
cruft full of cavities, which (if the edge of the fpecimen be
cautioufly pared away) may often be found to extend even into
the very fubftance of the ftone, See Dr. Smith’s Tour above
quoted. Micheli mentions, p. 97, feveral Lichens which bear
their fhields in cavities; his No. 21 and 22 belt agree with
ours, but not having feen his fpecimens we dare not pofitively
quote him. We have not indeed feen Mr. Relhan’s nor Dr.
Sibthorp’s L. immerfus, but there can fcarcely be any doubt of
theirs being the fame with ours.