/ £ . [ 2 4 7 2 ]
SPILOMA punctatum.
Dotted Spiloma.
CRYPTOGAMIA Alga.
Gen. Char. Receptacles shapeless, without a border,
powdery, in an uninterrupted crust.
Spec. Char. Crust th in , somewhat powdery, white.
Receptacles scattered, minute, dot-like, solid,
black, with superficial dark brown powder.
Syn. Spiloma punctatum. Turn. & Borr. Lick. Brit,
v. 1. 40.
(xATHERED on old oaks at Coltishall, Norfolk, by Mr. D.
Turner, who favoured us with this specimen.
The crust forms small irregular patches, minutely edged with
black, and scarcely an inch wide, thin, but of more substance
than in some others of the genus, white and slightly powdery on
the surface. When rubbed it becomes greenish, like that of many
Lichens. Receptacles very numerously sprinkled all over the
crust, into which they are sunk, looking like minute black dots.
Their substance is solid, as in S. tumidulum, t. 2151 *, but
greyish internally, with a black external coat, covered with a
very minute brownish-black powder.
The solidity of the internal part of the fructification makes the
authors above cited doubtful whether this plant should not be
referred to Acharius’s genus Arthonia.
* S. gregarium. Turn, tf Borr. Lick. Brit, v. 1. 42.