22 i [ 1941 ]
LICHEN circinatus.
Radiant Crustaceous Lichen.
CRYPTOGAMIA Algce.
Gen. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
S pec. Char. Crust tartareous, orbicular, greyish,
cracked, marked with radiant marginal lobe-like
furrows. Shields central, crowded, depressed,
blackish brown, at length angular; with a smooth
white border.
Syn. Lichen circinatus. Ach. Prod. 100. Per soon
in lis t. Ann.fasc. 7. 25. Schrad. Spirit. 94.
L. subimbricatus. Relh, 459. ed. 1. 427. t. 6. With,
v. 4. 18. Hull. 289.
L. radiosus. Hoffm. Enum. 62. t. 4. f . 5 .
Psora radiosa. Hoffm. PL Lick. v. 3. 12 . t. 5 9 . ƒ 1.
t . 60.f . 3.
Parmelia circinata. Ach. Meth. 189. Winch Guide,
v. 2. 54.
T h i s grows on flat calcareous stones, and was sent by the
Rev. G. R. Leathes from Bury. We remarked it as a new
species on rocks below the bridge at Kirkby Lonsdale, Westmoreland,
in 1783. It was however unquestionably first
distinguished at Cambridge by Mr. Relhan, who published it
the following.year. Hoffmann published it the same year,
and we know not why neither of their specific names has been
retained. To avoid contention and confusion, we submit to
that just authority which such a leader in any scientific department
as Dr. Acharius has a right to claim, but we wish
he had followed the apt name of our countryman, whose
figure, drawn in 1783 by Bolton, is excellent. Had circinatus
been in itself exceptionable, we should have acted as on a
former occasion ; see t. 1778.
The species before us is known by its crust, which though
perfectly tartareous and inseparable, is marked with such
radiating lines and furtows as to seem lobed and almost imbricated.
The innumerable shields are much depressed, occupying
the centre, and so crowded as to become angular:
their disk dark brown or blackish, deciduous: margin whitish,
smooth and entire.