Hab. On rooks and stones.—Bistr. General and common in the
Channel Islands and England and Wales. Somewhat rare in Ireland,
rare in Scotland.—B. M. Green Island, Jersey ; near Lewes, Newhaven
and Downs, Sussex; Newlyn Cliff, Cornwall; Shanklin, I. of Wight;
near Cirencester and Selsby Hill, Gloucestershire ; Walthamstow,
Little Baddon and Wickham Bishops, Essex ; Twycross, Leicestershire
; near Tenby, Pembrokeshire ; Llangollen, Denbighshire ; Malvern,
Worcestershire ; near Yarmouth and Market Dereham, Norfolk ;
Cherry Hinton Church, Cambridgeshire ; Pinching Thorpe Wood and
near Ayton, Cleveland, Yorkshire; Hartside Fell, Cumberland; Ben
Lawers, Perthshire; near Cork; Eoss, Clare; Killery Bay, Letter-
more and Doughruagh Mt., Connemara, Galway.
4. Rh. chlorophæum A. L. Sm.—Thallus yellowish-white,
warted or cracked-areolate, unequal, scattered or subdeterminate
(K + yellow, then red). Apothecia small, subinnate-sessile,
black, slightly pruinose, plane or convex ; hypothecium dark-
brown ; paraphyses ra th e r stout, discrete, thickened and brown
a t the tips ; spores dark-brown, oblong, 3-septate and irregularly
muriform, brown, without an epispore, 0,015-20 mm. long,
0,010-12 mm. thick ; hymenial gelatine blue with iodine.—
Lecidea cldorophæa Hepp. ex Leight. Lich. El. p. 328 (1871);
ed. 3, p. 348.
Closely allied to f. epipolia of the preceding species, but differing
in the more constantly muriform spores and in the thalline reaction.
Hab. On rooks and flints.—Distr. Eare in S. England and S.
Wales.—B. M. S. England ; Tenby, Pembrokeshire.
5. Rh. soreumidium A. L. Sm.—Thallus pale or pallid-greyish,
thickish, wrinkled or warted-congested, limited (K —, CaCl — ).
Apothecia crowded, sessile, small a t first, plane, wrinkled,
margined and bluish-grey-pruinose, becoming convex and immarginate
and often connate ; hypothecium dark-brown or
brownish ; paraphyses indistinct, somewhat irregular, dark-brown
a t the tips and granular-inspersed ; spores ellipsoid, 3-septate and
generally muriform, brown, 0,013-20 mm. long, 0,008-10 mm.
thick ; hymenial gelatine deep-blue with iodine.—Lecidea soreu-
midia Stirton in Scott. Nat. iv. p. 29 (1877) ; Leight. Lich.
FI. ed. 3, p. 375. Specimen not seen.
Perhaps only a form of Bh. alboatrum.
Hab. On dead wood.—Distr. Alpine districts in Scotland (Ben
Brecht, Argyll).
6. Rh. geog-raphicum DC. El. Fr. ii. p. 365 (1805).—Thallus
citrine or bright-greeriish-yellow, determinate, thickish or rather
thin, areolate, the areolæ smooth, plane, contiguous or sub-
contiguous (K - , CaCl - , medulla I + bluish) ; hypotballus
black. Apothecia small or moderate in size, innate, plane or
somewhat convex, marginate, black ; hypothecium blackish ;
paraphyses conglutinate, variously dark-coloured a t the apices ;
spores broadly fusiform-oblong, very dark-coloured, sometimes
halonate, 3-sej)tate, frequently with longitudinal or oblique septa,
0,024-40 mm. long, 0,011-18 mm. thick ; hymenial gelatine deep-
blue with iodine.—Mudd Man. p. 221, t. 4, fig. 83 pro parte.
Lichenoides nigro-flavum, tabulae geographicse instar pictum Dill.
Hist. Muse. p. 126, t. 18, f. 5 (1740). Lichen geographicus
L. Sp. PI. p. 1607 (1753); Huds. El. Angl. p. 442; Lightf.
El. Scot. ii. p. 801 ; Engl. Bot. t. 245 ; With. Arr. ed. 3,
iv. p. 12 (1796). Lecidea geograpliica Schær. Spicil. p. 124 (182S)
& Enum. p. 105, t. 5, f. 3 ; Hook, in Sm. Engl. FI. v. p. 178
pro p a rte ; Tayl. in Mackay El. Hib. ii. p. 121; Cromb. Lich.
Brit. p. 9 3 ; Leight. Lich. El. p. 346; ed. 3, p. 372 pro parte.
L. atrovirens var. geograpliica Hook. El. Scot. ii. p. 37 (1821);
S. F. Gray Nat. Arr. i. p. 465.
Exsicc. Leight. nos. 128, 129, 306 ; Mudd n. 196; Larb.
Lich. Hb. n. 352 (f. contigua).
A variable plant both as to thallus and ap)otheoia. In its more
typical and developed state, the thallus, which often spreads extensively,
is limited and usually intersected by the black hypotballus, so
th at, as Dillenius says, “ it is divided, as it were, into compartments
like a map,” whence its specific name. When the thallus is contiguous
at the circumference, it is var. contigua (Mudd I. c. ; Lecidea
geograpliica var. contigua Fr. Lioh. Eur. p. 827 (1831) ; f. contigua
Leight. Lioh. El. ed. 3, p. 373). The numerous apothecia situated
either on or between the areolæ are a t times more or less confluent,
the margin usually very thin is occasionally more developed, becoming
tumid and prominent (var. urceolatum Mudd I. o. ; Lecidea geo-
graphica var. urceolata Schær. Enum. p. 106 (1850) ; f. urceolata
Leight. I. 0. p. 374).
Hab. On rooks and boulders, granitic, schistose, quartzose and
arenaceous, from maritime to alpine situations.—Distr. General and
abundant in most parts of Great Britain, where it attains the summits
of the highest mountains ; not uncommon in the Channel Islands ;
apparently rarer in Ireland.—B. M. La Moye, Jersey ; Islands of
Guernsey and Alderney ; Pentire, St. Minver, Temple Moor and
Lamynack Cliff, near Penzance, Cornwall ; Dartmoor, Devon ; near
Eiohard’s Lock, Ulting, Essex ; Bardon Hill and Charnwood Forest,
Leicestershire ; Malvern Hill, Worcestershire ; Cader Idris, Aberdovey,
Barmouth and Corwen, Merioneth ; Glyder and Capel Curig,
Carnarvonshire (f. urceolatum) ; Hafod, Cardiganshire ; Longmynd,
Wrekin Hill, Caer Caradoc and Pontesford Hill, Shropshire ; Ba ttersby
Moor (f. urceolahim), Kildale Moor and Lounsdale, Cleveland,
Yorkshire ; Teesdale, Durham ; Lamplugh, Cumbeiiand, The Cheviots,
Northumberland; near Loch Skene, Moffatdale, Dumfriesshire;
Arthur’s Seat, Edinburgh ; Glen Creran, Argyll ; Sidlaw Hills,
Forfarshire ; Craig Calliach, Ben Lawers and Biniam Hill, Dunkeld,
Perthshire ; near Portlethen, Kincardineshire ; Morrone, Braemar,
and Huntly, Aberdeenshhe; Ben Nevis, Invernessshire; Cuchullin
Hills, I. of Skye ; near Loch Shin, Sutherland ; Keim-an-Bigh,
Cork ; Killarney, Kerry.
Var. atrovirens Koerb. Syst. Lich. Germ. p. 263 (1855).—
Thalline areolæ smaller, more or less scattered and somewhat