F ig . 2.
Jl£a.rc7i 7*? 7(937.
2687. (Pig. 1.)
LECIDEA prominula.
Prominent small-shielded warty Lecidea.
CR YPTOGA MIA Lichenes.
Gen. Char. Patellulce sessile or more or less immersed,
with a margin of a substance different
from the thallus.
Spec. Char. Crust thin, somewhat tartareous, minutely
warty, smoky gray or brownish. Patellulee
superficial, small, black, internally gray; disk
flat; margin slightly elevated, mostly entire.
(3. Crust browner, more level, minutely cracked.
r p
JL HALLUS in patches of a roundish outline, and two
or three inches in diameter, composed of minute, convex,
somewhat tartareous warts, of a smoky or ashen gray,
green within, more or less dispersed or confluent on an
obscure lead-coloured substratum. Patellulas black, a
little tinged with brown when dry, about as large as poppyseed,
numerous, often crowded in the central parts of the
patch, superficial, contracted at the base ; their margin obtuse,
entire, or occasionally a little waved or indented;
smooth, sometimes polished ; their disk concave in young
patellulae, in full-grown ones flat and nearly level with the
margin, with which it agrees in hue, but under a magnifier
it appears not smooth, but roughish, as if minutely dotted ;
internally gray or pale brownish.
Such is our a, which is occasionally met with on the
Sussex Downs, on flints that have been long exposed to the
weather. Our /3, which we venture to refer to the same
species, without being able to assert that we have traced
the one to the other by intermediate specimens, was found
on a block of close-grained sandstone on the sea-shore
near Rye. In this no traces of the dark substratum are
discoverable, and the warts, or granulations, are more con