CRYPTOGAMIA Algae.
Gen. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust smoky-brown, formed of minute
tessellated warts, with a radiated, marginal fringe.
Shields immersed in each wart, concave, blackish,
with an undivided, elevated, pale margin, of the
substance of the crust.
Syn. Urceolaria fimbriata. Ach. Meth. 145.
F o u n d on flints upon the South-Downs, Sussex, by Mr.
W. Borrer, who has justly determined the synonym of Acha-
rius. Mr. Sowerby has observed it to be very common in different
degrees of perfection on flinty pebbles in exposed sunny
places.
The crust is of an uniform light smoky brown, tessellated,
consisting of numerous, crowded, angular, convex, smooth
warts, which are less distinct and more polished towards the
margin, where they vanish gradually into a thin, dilated, inseparable
border, sometimes coloured like the crust, and rather
granulated than fibrous; at other times, (where the flint is
broken and polished,) blackish, and distinctly radiated like a
fringe, bearing scattered rudiments of future warts. Each of
the perfect warts bears one, rarely more, small irregular concave
shields, with a blackish, somewhat glaucous, disk, and
an elevated, pale, undivided, roughish border, of the substance
of the crust or wart, and looking as if it had become visible
by rubbing. The old shields are so like those of an Acharian
Parmelia, that we hesitate much about the genus Urceolaria,
and in that uncertainty have been obliged to change the specific
name for the present, as there is an old Lichen jimbriatus.
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