478 LICHENACEI, [ZBCANORA. 
Barmouth, Merionethshire; Trefriw Falls, Carnarvonshire ; Teesdale, 
Durham. Appin and Glencoe, Argyleshire ; Glen Falloch and Ben Lawers,. 
Perthshire ; Glen Callater, Braemar, Aberdeenshire. Ballaghbeama Gap 
and Dunkerron, co. Kerry ; Connor Cliffs, Dingle, co. Kerry; Ballynakill 
and Lough Inagh, Connemara, co. Galway. 
177. L. flavida Hepp, Exs. (1860) n. 630; Fr. fil. Vet. Ak. 
Handl. vii. (1867) p. 24.—Thallus effuse, very thin, rimoso-areolate, 
subleprose, pale ochraceous or glaucous-grey (K—, CaCl—). Apo- 
thecia very minute, innate, at first concave, then plane, black; the 
thalline margin thin, entire; spores 8ne, ellipsoid, 0,012-18 mm. 
long, 0,007-11 mm. thick ; paraphyses not discrete, bluish towards 
the apices; hymenial gelatine deep blue with iodine.—Leight. Lich. 
FL. ed. 3, p. 195.—Aspicilia ochracea (non Schaer.) Mudd, Man. 
p. 163. Lecanora gibbosa forma lacustris Leight. Lich. Fl. ed. 1, 
p. 210 pro parte.—Brit. Exs.; Leight. n. 292; Mudd, n. 136. 
A rather inconspicuous plant which, in dry weather, might readily be 
overlooked, but is well characterized by the characters given. When sub- 
ochraceous, the black apothecia and the more leprose thallus at once 
distinguish it from the preceding species; while the minute fruit, apart 
from anatomical differences, definitely separates it from the ochraceous 
state of L. calearea, The apothecia are usually very numerous, 
Hab, On moist rocks and stones in hilly districts——Distr. Found only 
in N. England.—-B. M.: Cockshaw Bank, Cleveland, Yorkshire, 
178. L. Prevostii Fr. fil. Lich. Scand. (1871) p. 288.—Thallus 
effuse, very thin, continuous, whitish, greyish- or fleshy-white, often 
obsolete (K—, CaCl—). Apothecia minute, deeply immersed, sub- 
rotundate or variously difform, concave, carneous or pale-carneous, 
the proper margin connivent, discrete from the thalline margin ; 
spores ellipsoid, 0,014-22 mm. long, 0,009-11 mm. thick; para- 
physes not discrete; epithecium colourless; hymenial gelatine 
bluish, then sordidly wine-coloured with iodine.—Leight. Lich. FI. 
ed. 3, p. 198; Cromb. Grevillea, xix. p.58.—Lecanora epulotica var. 
Prevostii Cromb. Lich. Brit. p. 55; Leight. Lich. Fl, ed. 1, p. 212. 
Gyalecta geoica Ach.? Leight. Angio. Lich. t. 15. fig. 1. Gyalecta 
Prevostit Fr. Lich. Eur. (1831) p. 197, 
At one time regarded by Nylander as a variety of the following species, 
differing chiefly in the irregular foveolate apothecia. It belongs, how- 
ever, to this subsection, from the character of the gonidia, which fide Th. 
M. Fries (Lich. Scand. p. 289) are 0,009-16 mm. in diameter. In 
the British specimens the thallus is usually confused with the substratum, 
whence forma proletaria Fr. fil. 7. c. It is then, from the colour of the 
very small, though numerous, apothecia, a rather inconspicuous plant. 
Hab, On calcareous rocks in upland tracts of hilly and mountainous 
districts.— Distr. Seen from only a few localities in W. and N. England, 
as also from the Grampians, Scotland—B. M.: Bathampton Downs, 
Somerset ; Teesdale, Durham; Levens, Westmoreland. Craig Tulloch, 
Blair Athole, Perthshire; Craig Guie, Braemar, Aberdeenshire. 
