CRYPT0GAM1A Algae.
Gen. Char. Receptacles shapeless, without a border,
hairy and powdery, in an uninterrupted crust.
Spec. Char. Crust very thin, membranous, whitish,
swelling under the receptacles, which are convex,
roundish, variegated with grey and black.
S yn. Spiloma Vitiligo. Ach. Meth. 10. t. ! .ƒ . 4.
F o u n d upon old posts and other dead wood long stripped
of its bark, which it covers with an apparent hoary mouldiness,
that slightly stains the finger if touched. The acute
Professor Acharius first established this genus, which we now
gladly adopt, more especially as some late discoveries seem to
us to confirm it. The essential character of Spiloma consists
in the indeterminate form of its receptacles and in their hairy
as well as powdery disk, destitute of any proper edge or border,
circumstances abundantly sufficient to separate it from Lichen,
Opegrapha, Lepraria, and all others.
In this species when magnified the crust proves to be thin,
membranous, of a silvery greyish white, smooth and even,
except where the numerous fructifications occur, under each
of which it is considerably elevated into roundish irregular
warts, of various sizes. The surface of each wart becomes a
black, powdery, minutely hairy disk, variegated with grey,
without any real border, though the tumid edges of the elevated
crust resemble one. The powdery part we presume to
be the seeds. Mr. W. Borrer favoured us with this minute
plant, which seems to be not uncommon, though easily overlooked
or neglected by trivial observers.
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