476 LICHENACEI. [LECANORA. 
and on the S. and Central Grampians, Scotland.—B. M.: Cunswick Scar, 
Westmoreland. Craig Calliach, above Loch-na-Gat, Ben Lawers, and 
Craig Tulloch, Blair Athole, Perthshire. 
174. L. poriniformis Nyl. Flora, 1865, p. 353—Thallus effuse, 
thinnish, firm, rimoso-diffract, greyish or pale-grey (K+yellow). 
Apothecia small, innate in convex, somewhat prominent verruce, 
pertusarioid, pale or brownish; the epithecium pale, punctiformi- 
contracted ; spores 6—8ne, ellipsoid, 0,070-80 mm. long, 0,034-50 
mm. thick; paraphyses slender; hymenial gelatine bluish, then 
tawny-yellow with iodine.—Carroll, Journ. Bot. 1866, p. 23; 
Cromb. Lich. Brit. p. 56; Leight. Lich. Fl. p. 190, ed. 3, p. 203.— 
Brit, Exs.; Cromb. n. 74. 
Looks exactly like a Pertusaria, allied to P. xanthostoma Somm. 
The characters, however, of the hymenium, of the thecse (which are 
fugacious), and of the spores show that it is a Lecanora distantly related 
to the preceding species. The thallus spreads somewhat extensively 
with the fertile verruce scattered or approximate. Usually there is but 
a single apothecium in each verruca, though not unfrequently there are 3 
or 4, when the verruce are rather larger. 
Hab. On schistose rocks and walls, rarely incrusting mosses, or on 
trunks of old firs, in ‘maritime and subalpine districts.— Distr. Local and 
scarce among the 8. and Central Grampians and on the N.E. coast of 
Scotland.—B. M.: Ben Lawers and Craig Tulloch, Perthshire; near 
Portlethen, Kincardineshire. 
175. L. Dicksonii Nyl. ea Carroll, Journ. Bot. (1867) p. 255.— 
Thallus determinate, thin, smooth, rimose or areolato-rimose, 
ochraceo-ferruginous, opaque (K—, CaCl—); hypothallus thin, 
black, limiting the thallus. Apothecia lecideine, small, innate, 
concave, black, internally blackish (greyish in the centre), the 
proper margin thick, black; spores 8ne, ellipsoid, 0,011-14 mm. 
long, 0,006-8 mm. thick ; hypothecium brownish-black ; paraphyses 
not discrete, fuliginous towards the apices; hymenial gelatine 
bluish, then wine-red with iodine——Cromb. Lich. Brit. p. 55; 
Leight. Lich. Fl. p. 211, ed. 3, p. 196.—Lzchen Dicksoniz Ach. 
Prodr. (1798) p.76. Lecidea melanophewa Fr., Mudd, Man. p. 206. 
Lecidea deri (non Web.) Tayl. in Mack. Fl. Hib. ii. p. 122; Sm. 
Eng. Fl. v. p. 178; Hook. Fl. Scot. ii. p. 38; Gray, Nat. Arr. 
i. p. 466. Lichen Gderi Eng. Bot. t. 1117; With. Arr. ed. 3, iv. 
p. 11 pro parte.— Brit, Ewvs.: Leight. n. 127; Cromb. n. 72. 
By many authors regarded as a Lectdea, with much the aspect of 
L. Gderi, with which it has been confounded ; but its most appropriate 
place is in this section. The peculiar colour of the thallus, as in various 
other instances, is owing to suffusion with peroxide of iron. Typically, 
according to specimens from Kerguelen Land, it is greyish (vide Linn. 
Soc. Journ. Bot. xv. p. 190 s.n. Lecidea sincerula Nyl.). The apothecia 
are numerous and at times somewhat crowded. 
Hab. On rocks and walls, chiefly schistose, in mountainous regions,— 
Distr, Somewhat local, though usually plentiful in Great Britain and in 
