LECIDEACEÆ
plane (form oUiterata Leight. Lioh. FI. ed. 3, p. 285), probably from
being denuded by water, and also in colour, which is rarely somewhat
leaden-coloured, evidently owing to maceration from a sterile crusta-
ceous lichen with which it is associated. In its fully developed
condition, and with pruinose apothecia, it is var. /3 elegans Th. Fr.
in Nov. Act. Reg. Soc. Upsal. p. 307 (1861); this form occurs rarely
on tne boottish mountains. The apothecia, common in the British
specimens, are at times somewhat crowded and then more or less
angulose. When young, they are concave and immersed in the
areolae with, as it were, a spurious thalline margin (iormsubconsentiens
Leight. Lich. FI. ed. 3, p. 284).
Hab. On rocks and stones, granitic and schistose, rarely arenaceous,
in mountainous regions.— JVsZr. Bare in the North of
England, more frequent in Wales and Ireland, and in the central
counties of bcotland.—A. Af. Cader Idris and Corwen, Merioneth;
bnowdon Carnedd Dafydd, Glyder Mts., Trefriw and Llyn
Ogwen, Carnarvon; Abden Burf, Shropshire; Teesdale, Durham;
Eavensborrow Crag, Kent River Valley, Westmoreland ; West Water,
n V®“ Bawers, Craig Calliach, Crianlarioh, and Glen Falloch,
Eerthsfiire; Canlochan, Forfarshire; Barcaldine, Lome, and Ben
Cruachan, Argyll ; Glen Callater and Craig Guie, Braemar, Aberdeen-
stiire; Glen Nevis, Lochaber, and Invermoriston, Invernessshire;
CuoJiuUin Hills, Isle of Skye ; Appleoross, Ross ; Looh Shin, Suther-
n “ Mt. and Mangerton, Kerry; Kylemore, Doughruagh
Mt., Connemara ; Ballynakill, Galway.
111. L. corollidia Stirton in Trans. Glasgow Soc. Nat. 1875,
p. 88.—Thallus pale or pallid-ashy-grey, somewhat thick, diffract-
areolate, ra th e r plane (K + yellow then red). Apothecia black,
adnate, large, plane, rugose, sometimes bluish-grey-pruinose with
a flexuose obtuse margin ; hypothecium thick, dark-brownish-black;
paraphyses indistinct, brown a t the apices ; spores ellipsoid, 0,015-
0,008-11 mm. thick.—Leight. Lich. FI. ed. 3,
p. 296. Specimen not seen.
Perhaps a form of A. Mooreana” (Stirton, I. c.). This species
seems from the description to be very nearly identical with L.
panæola, of which, except for the absence of cephalodia, it might be
only a growth form. ^
Hab. On rooks. Collected by Dr. Stirton at Thurso, Caithness.
mu P^^snterodes Nyl. in Flora Iviii. p. 363 (1875).—
lh a llu s yellowish-white, firm, areolate. Apothecia plane, margin-
ate, varying in size, scattered or crowded, the margin persistent,
flexuose, disc bluish-grey, pruinose or naked ; hypothecium dark-
reddish, brownish above ; paraphyses slender, yellowish a t the
taps ; spores ellipsoid, 0,014-22 mm. long, 0,008-12 mm. th ick ;
hymenial gelatine persistent, deep-blue with iodine.
In the single specimen in the British Museum, collected and
determined by Crombie, the thalline areolæ are somewhat scanty and
scattered, the apothecia are sometimes proliferous, minute fruits
being borne on the disc of older forms.
M. B ,„ L „ e „ , Perth-
67
113. L. contigua Fr. Lich. Eur. p. 298 (1831) pro parte.—
Thallus greyish-white or sometimes ashy-grey, usually rather
I thin, continuous, finely cracked granular or areolate, the areolæ
i continuous and flat or sometimes convex and somewhat tumid (K —,
) CaCl — ) ; hypotballus black. Apothecia seated on the thallus,
I varying in size, plane or convex, somewhat rough, the margin
S thick, obtuse, prominent, or sometimes almost obliterated ; hypo-
; thecium thick, blackish-brown ; paraphyses slender, subcoherent,
! dark- or olivaceous-brown a t the apices ; spores ellipsoid, large,
I 0,016-27 mm. long, 0,008-13 mm. thick ; hymenial gelatine blue
then wine-red with iodine.—Mudd Man. p. 209 (excl. syn. ; spore
' measurements too small) ; Cromb. Lich. Brit. p. 80 (excl. vars.
crustulata and speirea) ; Leight. Lich. El. p. 292 ; ed. 3, p. 299
(excl. forms meiospora and aggerata). Verrucaria contiqua Hoffm.
Deutschl. El. ii. p. 184 (1795).
The thallus and apothecia of this lichen vary considerably in
appearance, giving rise to a large number of varieties which have been
described by Leighton as forms. They are all distinguished by the.
characters of the apothecium, its thick dark-coloured hypotheoium
and somewhat large ellipsoid spores. When the thallus is limited
and intersected by the hypotballus, it is f. limitata Leight. (Lioh. FL
p. 292 ; ed. 3, p. 299) ; when it occurs'in round somewhat furfuraceous
patches with rather small apothecia, it is f. leprosa Leight. (Z. c.
p. 293). Another series of forms have a thick well-developed thallus
and occasionally very large apothecia; y&x. nobilis Fr. (Z. c. p. 301,
f. nobilis Leight. Z. c. p. 293) is characterized by having the thallus
thick, tartareous, areolate and turgid ; while f. Hoffmanni Leight.
(I. c.) is lighter in colour and less turgid with larger apothecia.
In var. notabiUs Nyl. (in Not. Sallsk. Faun. & PL Fenn n. ser. i.
p. 241 (1859)), (f. notabilis Leight. Z. c. ed. 8, p. 802), the thallus is
whitish and unequally minutely granulose, the granules dispersed or
sometimes in small clusters (aoervulate), resembling the thallus of
Stereocaulon condensatum. Leighton describes, a further evidently
rare form as i. pustulata (I. c. p. 302), which is yellowish-grey,
limited by the black hypotballus, and areolate, the areolæ plane with
central sorediate protuberances ; some of these are enlarged into
orbicular, rather flat tubercles, in which are embedded a conglomeration
of minute marginate black apothecia.
Hab. On rocks in maritime or hilly regions.—JDistr. Common
throughout Great Britain and Ireland.— A. M. Bndellion, Cornwall
(f. limitata) ; Crown, East Down, Dartmoor, Devon ; Leith Hill,
Surrey; Charnwood Forest, Leicester; near Malvern, Worcester;
(Æercaradoo, Haughmond Hill (f. leprosa), and near Ludlow, Shropshire
; near Monmouth ; Aran Mawddwy, Llyn Aran, Cader Idris,
and Dolgelly, Merioneth ; Carnedd Dafydd, Nant Ffranoon and
Capel Curig, Carnarvon; Eoughton, Lincoln; Ayton, Cleveland,
York-diire; Westwater, Forfar ; Loch-na-gat, Ben Lawers, Killin,
Glen Loohay, Craig Calliach, and Ben-y-gloe, Perthshire ; Barcaldine,
Lome, Achosragan Hill, Appin and Island of Lismore, Argyll
Morrone, Braemar, Aberdeenshire.
Form calearea Leight. Lich. PI. p . 292 (1871).—Thallus
creamy-white, tartareous, smooth, areolate, the areolæ plane or
P 2
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