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L I C H E N Acharii.
Acharian Lichen.
CRYPTOGAMIA Alga.
G en. Char. Male, fcattered warts. Female, fmooth
fhields or tubercles, in which the feeds are imbedded.
Spec. Char. Cruft fmooth, a little cracked, pale
brick-coloured. Shields funk in the cruft, reddifh.
Syn. Lichen Acharii. Achar. Prod. 33. cum ic.
L. lacuftris. With. v. 4. 21. 1. 3 1 ./. 4. Hull. 290.
F * O R v a rio u s fp e c im en s o f th is lit t le -k n ow n L ic h e n w e are
in d eb ted to th e R e v . M r . H a r r im an , and M r . O liv e r . I t
w a s firft fo u n d b y J . W . G r iffith , efq. in N o r th W a le s , w h o
fen t it to D r . W ith e r in g ; and is o n ly m e t w ith o n fu ch g r a n
it e fton e s , o r ro c k s , as are o c c a fio n a lly in u nd ated , as about
th e b ed o f th e T e e s , and fhores o f a lp in e la k e s , h a v in g in its
m o ft com m on ftate th e ap p e a ran c e o f an o ch ra c eo u s depofit
o f th e w a te r . T h e c ru ft , th o u gh n o t v e ry th ic k , is firm,
h a rd , fm o o th , an d e v en , as i f p a r t ly p o lilh ed , b e c om in g
m o re o r Iefs c ra ck ed b y a g e . T h e co lou r is a pale y e llow ifh
b r o w n ; in fom e fp e c im en s , w h ic h fe em n o t o th e rw ife d i-
ftin fit, d ir ty w h ite . T h e fhields are fm a ll, p re tty num e ro u s,
v a r io u fly fcatte red, fu n k in th e c ru ft, con c a v e , o f a deeper
o r m o re reddilh colou r th an th e c ru ft, furrounded a t firft b y
a p a le elevated b o rd e r, w h ic h afte rwards d ifap p e a rs . In th is
ad van c ed ftate o f L . Acharii, w e k n ow n o t h ow to c o n v e y a
b e tte r ide a o f it th an b y c om p a r in g it to a w a fh o f w a te r -co lo u r
m ix e d u p w ith a la rg e po rtion o f g um , o r fiz e , th e nume rous
a ir -b u b b le s fo rm ed b y w h ic h fe em , b y fu b fid in g , to h a v e left
m in u te dep re ffions fcatte red o y e r th e fu r fa c e , and th efe d e -
p re fiion s are the fh ie ld s .