PANNARIA.] LECANO-LECIDERI. 339 
convex and often with the thalline margin obliterated (form biatorordea 
Cromb. Grevillea, xviii. p. 43), , 
Hab. On earth-covered walls and hedge-banks, rarely on decaying 
stumps, in maritime and upland districts Distr. Rather local, though 
plentiful where it occurs in the Channel Islands, here and there through- 
out England; scarce in N. Wales, Scotland, and 8. Ireland.—B.M. : 
Quenvais and St. Brelade’s Bay, Island of Jersey; Islands of Sark, 
Guernsey, and Alderney. North Wootton, Norfolk; Epping Forest, 
Essex; near Bovey Tracey, S. Devon; St. Germains, Penzance, and 
Withiel, Cornwall; near Malvern, Worcestershire; Hay Forest, Here- 
fordshire; Barmouth, Merionethshire; Bangor, Carnarvonshire; Egle- 
stone, Durham; near Ennerdale Lake, Cumberland. New Galloway, 
Kirkcudbrightshire ; Airds, Appin, Argyleshire; Loch Tay and Killin, 
Perthshire. Co. Cork. 
4, P, Hookeri Nyl. Mém. Soc. Cherb. v. (1857) p. 109 ; Syn. il. 
p- 32.—Thallus radioso-crustaceous, appressed, greyish or greyish- 
brown, granuloso-corrugate in the centre, radiately lineato-plicate 
or only lobulato-effigurate at the circumference; hypothallus thin, 
black. Apothecia nearly moderate, plane, black or blackish, in- 
ternally pale, the thalline margin usually crenulate; spores ellipsoid, 
0,014-15 mm. long, about 0,009 mm. thick; hymenial gelatine 
bluish, then sordid-red with iodine.-—Mudd, Man. p. 125; Cromb. 
Grevillea, xviii. p. 43.— Lecanora Hookeri Hook. Fl. Scot. ii. p. 51. 
Lichen Hookeri Eng. Bot. xxxii. (1811) t. 2283. Pannaria leucc- 
lepis Cromb. Lich. Brit. p.42; Leight. Lich. Fl. p. 165, ed. 3, p. 151. 
Squamaria leucolepis Sm. Eng. Fl. v. p. 194.—Brit. Ews.: Leight. 
n, 267. 
An interesting species well characterized by the colours of the thallus 
and apothecia, as also by the nature of its habitat. The thallus when 
perfect is orbicular, placodioid, sometimes leaden-greyish, with the hypo- 
thallus little visible and at length evanescent. It is usually well fertile, 
with numerous, crowded apothecia, which in old plants are entirely black. 
Hab. On micaceo-schistose rocks in alpine places.—Disir. Very local 
and rather scarce on the summits of a few of the S. Grampians, Scotland ; 
reported also by Leighton, but very doubtfully, from N.W. Ireland (Con- 
nemara, co, Galway).—B. M.: Ben Lawers, Mael Graedha and Craig 
Calliach, Perthshire. 
Var. 3. leucolepis Nyl. Syn. ii. (1870) p. 33.—Thallus squamu- 
lose, greyish-white or lurid-greyish ; squamules subimbricate, sub- 
crenate, sometimes slightly striate towards the circumference. 
Apothecia black, the thalline margin subentire or at length subcre- 
nate; spores about 0,015-19 mm. long, 0,008-10 mm. thick.— 
Cromb. Grevillea, xviii. p. 43. 
Usually confounded with the type by British and other authors, but 
_distinguished by the less developed thallus and by the size of the spores. 
The apothecia also are fewer, with the thalline margin less crenulate. 
Hab, On decaying mosses upon rocks in alpine situations—Distr, Ex- 
tremely local and scarce on the summit of one of the 8. Grampians, Scot- 
land.—B. M.: Ben Lawers, Perthshire. 
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