casionally assumes a brownish tinge : internal substance
green. Tubercles numerous, scarcely so large as poppyseed,
sometimes clustered and confluent and much deformed,
which indeed they often are when growing single,
although then more generally of a tolerably regular orbicular
figure. When the crust is most perfect they are partially
immersed ; in other cases variable in prominency ;
most protuberant when -wet, and in that state black ;
when dry brownish or slightly pruinose : their surface
minutely wrinkled all over : their central part usually
more elevated than the circumference, now and then
slightly papillose, but more frequently rather conspicuously
dimpled, and at maturity pierced with a small pore.
Nucleus brownish, shrinking much when dry. Old tubercles
are often found irregularly broken, and in falling they
leave a shallow cavity in the mortar, or the base of the
shell sometimes remains in the form of a small black cup.
V. muralis is nearly allied to V- rupestris ; but its crust
is less continuous, and its tubercles less deeply immersed
and less regular in figure, as well as larger than in the
usual appearance of that Lichen. To a Verrucaria which
is probably the V. Dufourii of Flore Française, and to V.
viridula, it bears also considerable affinity ; but it appears
distinguishable from the former by its larger and more
prominent tubercles, and from both by its inconsiderable
crust. The crust of V. viridula, indeed, has sometimes,
when injured by insects, a very similar appearance ; but
the proper state of its surface is almost always to be traced
in some parts of the patch. The tubercles too of that plant
are larger and more conical. Still the most experienced
Lichenists will not, perhaps, be the most forward to decide
whether these two productions be truly distinct species.
Acharius, on the authority of a specimen from M. Dufour,
has described V. concentrica of Flore Française as a variety
of V. muralis, differing only in being almost entirely without
a crust and in the concentric disposition of the tubercles.—
W. B.
V E R R U C A R I A epipolæa.
Large-fruited Rock Verrucaria.
CRYPTOGAMIA Lichenes.
G en. Char. Tubercles of a different substance from
the thallus, simple, convex, not expanding, but
furnished with a central pore, and inclosing a
somewhat gelatinous nucleus.
S pec. Chau. Crust indeterminate, thin, tartareous,
somewhat powdery, greyish. Tubercles large,
prominent, mostly conical, brownish black, pruinose.
S yn. Verrucaria epipolaea. Ach. Lich. Univ. 285.
Syn. 95. Fing. Tent. Lich. Eiffl. 15.
F R O M St. Vincent’s Rocks. Several botanists now deceased
have also gathered this species : the Rev. Hugh
Davies in Wales, Mr. Brunton and the Rev. J. Harrlman
in the North of England, and Sir Thomas Gage m Ireland.
Our specimens agree with an authentic one from Acharius.
Crust spreading irregularly and indeterminately, very
thin yet somewhat tartareous, green within, externally
greyish, but always tinged more or less with red, and sometimes
almost rose-coloured, unpolished, with a rather
powdery appearance, continuous, or cracked in some parts
when dry into minute areolm. Tubercles rather remotely
scattered, of a size sometimes exceeding that of cabbage-
‘seed, minutely rugged, occasionally polished at the apex,
but usually all over of a dull black, with a tinge of brown,
and a little pruinose : they are for the most part regularly
orbicular and considerably prominent, rising from a flat
slightly immersed base into a conical or sometimes hemispherical
figure, now and then slightly raammillated. Frequently
the orifice is scarcely discoverable, even in lull