Hab. On schistose rocks in mountainous districts.-—Bistr. Local
and scarce in N. England, the N. Grampians, Scotland, and in W.
Ireland ; no donbt to be detected elsewhere.-—B. M. Alston, Cumberland
; Morrone, Braemar, Aberdeenshire ; near Letterfrack, Connemara,
Galway.
Var. y Mosigii Nyl. Lich. Scand. p. 230 (1861).—Thallus
chestnut- or greyish-brown, smoothish. Apothecia moderate or
somewhat large, innate, plane, thinly margined, pruinose, the
margin often flexuose and naked.—f. Mosigii Leight. Lich. El.
p. 288 ; ed. 3, p. 294 ; f. deusta Leight. Lich. El. p. 289 ; ed. 3,
I. c. L. fumosa var. Mosigii Ach. Lich. Univ. p. 157 (1810);
var. ¡3 deusta Mudd Man. p. 211 (1861) (non Eries).
Exsicc. Leight. n. 240 pro parte.
Differs chiefly in the pruinose apothecia which are either somewhat
scattered or crowded and at times confluent. The thallus is limited
by the hypotballus, which is also occasionally more or less visible
between the areolæ.
Hab. On granitic and schistose rocks in maritime and mountainous
districts.—Distr. Only here and there in Great Britain ; rare in S.
and W. Ireland (Connemara, Galway, fide Leight.) ; not found with
certainty in the Channel Islands.—B. M. Eoughton, Cornwall ; N.
Derbyshire ; Dolgelly, Merioneth ; The Wrekin, Shropshire ; near
Ayton, Cleveland, Yorkshire ; Achosragan Hill, Appin, Argyll ; Craig
Calliach, Perthshire ; near Portlethen, Kincardineshire ; Morrone,
Braemar, Aberdeenshire ; near Bantry, Cork.
149. L. nigrogrisea Nyl. in Elora Ixii. p. 357 (1879).—
Thallus indeterminate, moderate or thinnish, granulate-areolate,
greyish ; the areolæ subconvex, somewhat shining (K —, CaCl — ,
medulla I — ). Apothecia a t first plane and thinly margined,
then somewhat convex and almost immarginate, black; epithecium
and perithecium blackish ; hypothecium brown ; spores ellipsoid-
oblong, 0,007-11 mm. long, 0,001-5 mm. th ick ; hymenial
gelatine bluish, the asci a t length tawny-wine-coloured, with
iodine.—Cromb. in Grevillea viii. p. 113.
Distinguished from all. states of L. fuscoatra by the absence of
any thalline reactions and the smaller spores. In the specimen
seen, the apothecia are somewhat crowded. The spermogones,
occasionally present, have the spermatia straight, 0,006-8 mm. long,
0,0006 mm. thick.
Hah. On a mica-sohist wall in an upland district.^—B. M. Craig
Tulloch, Blair Athole, Perthshire (the only locality).
150. L. macula Tayl. in Mackay El. Hib. ii. p. 115 (1836) ;
Nyl. in Elora Ixii. p. 361 (1879).—Thallus determinate, thin,
areolate-rimose, smooth, the areolæ minute, concave, then somewhat
plane, more or less scattered, pale- or olive-gi'eyish (K —, CaCl — );
hypotballus very thin, black. Apothecia minute, innate, plane,
margined, black, the margin slightly prominent ; paraphyses
concrete ; epithecium bluish-brown ; hypothecium brown ; spores
oblong-ellipsoid, 0,006-8 mm. long, 0,003-4 mm. th ic k ; hymenial
gelatine pale-bluish then tawny-wine-red with iodine.—Cromb.
in Journ. Bot. xx. p. 275 (1882). L. perustula Nyl. I. c. p. 221 ;
Cromh. in Grevillea viii. p. 29. L . nitida Leight. Lich. El. ed. 3,
p. 295 pro parte (non Schær.).
Exsicc. Leight. n. 278.
Resembles a diminutive state of L. fuscoatra, differing in the
absence of any thalline reactions and the much smaller spores. The
numerous inconspicuous apothecia occasionally have the margins
paler.
Hab. On siliceous rocks in maritime and mountainous districts.—
Distr. Only a very few localities in Wales and W. Ireland ; probably
overlooked elsewhere.-—B. M. Barmouth, Merioneth ; Llanberis,
Carnarvonshire; Dunkerron, Kerry; Doughruagh Mt., Connemara,
Galway.
151. L. rivulosa Ach. Meth. p. 38 (1803) ; Nyl. Lich.
Soand. p. 222.—Thallus determinate, areolate-rimose or granulate-
areolate, mouse-coloured, greyish-brown or pale-greyish (K —,
CaCl — ) ; hypothallns blackish, limiting and intersecting the
thallus. Apothecia sessile, or adnate, somewhat plane, margined,
slightly scabrid, brownish-black or black, the margin thin,
flexuose, paler, paraphyses discrete, brown a t the apices ; hypothecium
pale ; spores ellipsoid or ellipsoid-oblong, slightly curved,
0,009-12 mm. long, 0,004-6 mm. th ick ; hymenial gelatine pale-
hluish, the apices of the asci deep-blue then wine-red with iodine.
—S. F. Gray Nat. Arr. i. p. 467 ; Hook, in Sm. Engl. El. v.
p. 179 ; Tayl. in Mackay El. Hib. ii. p. 125 ; Mudd Man. p. 199
(excl. var.) ; Cromb. Lich. Brit. p. 79 ; Leight. Lich. El. p. 285 ;
ed. 3, p. 291. Lichen.rivulosus Sm. Engl. Bot. t. 1737 (1807).
Exsicc. Leight. n. 302 ; Mudd n. 168 ; Larb. Lich. Hb.
n. 309; Johns, n. 353.
Easily recognized by the brownish-black hypothalline lines with
which the thallus is usually intersected, and which suggested the
trivial name. When the thallus is more granulose, the granules are
depressed, plane, and either contiguous or discrete (f. depressa Leight.
ed. 3, p. 291). Very rarely it is evanescent, the hypotballus and
fructification only being visible (f. depauperata Leight. I. c.). The
numerous though scattered apothecia are in moist situations »often
brownish-flesh-coloured, but become darker in the herbarium. The
spermogones are frequent, verrucæform, scattered or confluent, with
spermatia oblong, 0 ,0 0 8 -4 mm. long, 0,001 mm. thick.
Hab. On rocks, chiefly granitic and quartzose, in maritime and
mountainous districts.—Distr. Rather local, but plentiful where it
occurs, in the Channel Islands, S., W. and N. England, Wales,
Scotland and N.W. Ireland.—B. M. Sark and Guernsey; near
Haytor, Dartmoor, Devon ; Roscorla and Kymyal Cliff, Penzance,
Cornwall ; near Seaford, Sussex ; Mynydd Gader, Dolgelly, Barmouth,
and Cader Idris, Merioneth ; Holyhead, Anglesea ; Kildale
Moor, Cleveland, Yorkshire ; the Cheviots, Northumberland ; B a rcaldine
and Appin, Argyll; Crianlarioh, Ben Lawers, and Ben-y-gloe,