subtended by the shell, so that when a tubercle falls off a
black ring is left surrounding a bare spot. The nucleus
of ripe tubercles escapes in drying in the form of a little
white spicule, and leaves the pore rather more conspicuous
than in the growing plant. When dried, thin specimens
are of an oil-green* ; thicker ones of a hair-brown*,
or sometimes, probably when the plant has grown in a
shady place, greyer, or almost cream-coloured. The original
hue is not recoverable by the application of moisture,
which the crust does not readily imbibe. In the dried
state the surface loses the minute wrinkles, and is remarkable,
especially in young specimens, for its oiled-like appearance
: the edges are sometimes obscurely zonate.
In confluent patches, narrow dark seams often mark the
boundaries of the originally separate plants.
So nearly does this curious Verrucaria agree with the
descriptions of V. mucosa of Wahlenberg and Acharius,
that it might be supposed the same ; but a small specimen
from Acharius, in the museum of the Linnean Society,
rather favours the opinion expressed by Fries, in his Li-
chenogr. Eur. Reform., that that Lichen is but a state of
V. maura, t. 2456, a species distinguishable in its perfect
state from V. submersa by its black colour when dry, and
by having its surface minutely cracked all over. Dried
specimens of V. submersa have more of the appearance of
V. nitida, t. 2607, f 1, than of any other of our species, but
want the minute grey dots that are sprinkled over the surface
of that Lichen.—W. B.
* Werner’s Nomenclature of Colours, ly Syme. Edinburgh, 18X4.