388 LICHENACEL. [LECANORA. 
Hab. On calcareous rocks, rarely on flints in maritime and mountainous 
districts. — Distr. Rather local, though common where it occurs in Great 
Britain ; not seen from Ireland.—B. M.: Reigate, Surrey ; Lydd Beach, 
Kent; Peasemarsh and near Lewes, Sussex; Isle of Wight; Cunning 
Dale, Buxton, Derbyshire; Island of Anglesea; Craig-y-Rhiw, Oswestry, 
Shropshire ; Eglestone, Durham ; Leven’s Park, Westmoreland ; Bywell, 
Northumberland. King’s Park, Edinburgh; Achrosagan Hill, Appin, 
and near Ben Cruachan, Argyleshire; Craig Tulloch, Blair Athole, Perth- 
shire; Craig Guie and Morrone, Braemar, Aberdeenshire. 
Form incrustans Cromb. Grevillea, xviii. (1889) p. 46.—Thallus 
very thin, white, usually evanescent. Apothecia minute, immersed, 
plane or slightly convex, thinly margined.—Lecanora rupestris 
forma incrustans Leight. Lich. Fl. p. 191, ed. 3, p. 203. Lecidea 
yupestris 3. inerustans Mudd, Man. p. 194. Patellaria incrustans 
DC. Fi. Fr. ii. (1805) p. 361. 
Differs in the smaller, immersed, margined apothecia, which, if a con- 
stant character, would render it a distinct variety. At times, however, 
these in the same specimen become at length somewhat prominent and 
immarginate, so that it can rank only as a form. 
Hab. On calcareous rocks in maritime and mountainous districts.— 
Distr. Seen only from §.W. England, the 8.W. Highlands, and the N. 
Grampians, Scotland, though reported also by Leighton from W. England 
(Ludlow, Shropshire).—B. M : Anstey’s Cove, ‘Torquay, 8. Devon. 
Island of Lismore, Argyleshire; Morrone, Braemar, Aberdeenshire. 
Subsp. L. Siebenhaariana Nyl. ex Stiz. St. Gall. Nat. Ges. 1874, 
p. 215.—Thallus effuse, rimoso-areolate, unequal, whitish or greyish. 
Apothecia small, adnate, convex, at first orange-coloured, at length 
sordid-olive or brownish tawny-yellow, internally dark ; spores as 
in the type-——Cromb. Journ. Bot. 1885, p. 195.—Biatora Sieben- 
haariana Koerb. Syst. Lich. Germ. (1855) p. 207. 
Characterized by the differently coloured apothecia and the dark hypo- 
thecium. This, as observed by Fries fil., Lich. Scand. p. 425, in the 
young apothecia is usually violet-rose-coloured, then becoming more and 
more brownish, though in these it at times presents the natural colour of 
the type. The thallus is at times almost evanescent and visible only 
around the apothecia, which are small and scattered, or minute and 
several congregate. 
Hab. On moist mica-schist rocks in alpine situations.—Distr. Very 
sparingly on two of the S. Grampians, Scotland.—B. M.: Summits of 
Ben Lawers and Craig Calliach, Perthshire. 
50. L. nivalis Nyl. Not. Sallsk. pro F. & Fl. F. Forh, v. (1866) 
p. 129.—Thallus effuse, very thin or slightly granulate, whitish or 
greyish-white (K+ purplish), Apothecia small, adnate, ochraceous 
or orange-coloured, at first plane with an evanescent thalline mar- 
gin, at length somewhat convex, biatorine with thin, entire proper 
margin (K+ purplish) ; spores oblongo-cylindrical, simple or faintly 
l-septate, 0,024-38 mm. long, 0,005-7 mm. thick; paraphyses 
