418 LICHENACEI. [LECANORA. 
S.W. Highlands of Scotland and N.W. Ireland.—B. M.: Glen Creran, 
Barcaldine, Argyleshire. Letterfrack, Connemara, co, Galway. 
97. L. prepostera Ny]. Flora, 1873, p. 19.—Thallus deter- 
minate, thin, smoothish, areolato-rimose, whitish, darkly limited and 
subfimbriate at the circumference (K+yellow, then cinnabarine- 
reddish, CaCl—). Apothecia moderate, blackish, opaque, glaucous- 
suffused or subdenudate, the thalline margin rugulose or subcrenate ; 
spores ellipsoid, 0,009-14 mm. long, 0,005-6 mm. thick ; paraphyses 
slender ; epithecium yellow-inspersed ; hymenial gelatine, especially 
the thece, bluish with iodine-—Cromb. Grevillea, 1873, p. 141; 
Leight. Lich. Fl. ed. 3, p. 173. 
Looks at first sight as if only a peculiar variety of Z. atrynea, but is 
well distinguished by the smaller spores, the reactions of the thallus and 
hymenial gelatine. The two specimens seen by me are evidently an old 
state of the plant, and though the apothecia are numerous the spores are 
seldom present. 
Hab. On basaltic rocks in a maritime district —Distr. Extremely 
local and rare in one of the Channel Islands.—B. M.: Rozel, Island of 
Jersey. 
98. L. albella Ach. Vet. Ak. Hand]. 1810, p. 137; Nyl. Flora, 
1872, p. 365.—Thallus determinate, thin, smooth, whitish (K+ 
yellow, CaCl—). Apothecia moderate, plane or slightly convex, pale- 
flesh-coloured, cesio-pruinose or naked, the thalline margin entire ; 
paraphyses not very discrete; epithecium granulose (CaCl—) ; spores 
0,010-12 mm. long, 0,005-8 mm, thick; hymenial gelatine bluish, 
then nearly colourless or somewhat yellowish, the thece tawny 
wine-red (their apices bluish) with iodine.—Gray, Nat. Arr. i. 
p. 453; Sm. Eng. Fl. v. p. 191; Mudd, Man. p. 148; Cromb. Lich. 
Brit. p. 51; Leight. Lich. Fl. ed. 3, p. 206.—L. subfusca forma 
albella Leight. Lich. Fl. ed. i. p. 204. Lichen albellus Pers. in Ust. 
Ann. Bot. xi. (1794) p. 18; Eng. Bot. t. 2154, 
In several respects allied to more than one of the preceding species, from 
which externally it may be discriminated by the pale buff-coloured apo- 
thecia, which are rather scattered or sometimes crowded. It is, however, 
more definitely separated by the spermogones, which, as stated by Nylander 
(Flora, 1872, p. 250, note 2), are pale above. The spermatia are 
0,016-20 mm. long ( fide Nyl. in htt.). It is a somewhat variable plant, 
presenting the following forms. 
Hab. On smooth bark of trees in wooded maritime and upland districts. 
—Distr. As yet only here and there sparingly in Great Britain and Ire- 
land.—B. M.: Epping Forest, Essex; New Forest, Hants; Falls of 
Becky, 8S. Devon; Savernake Forest, Wiltshire; Hay Park, Hereford- 
shire ; Island of Anglesea, Barcaldine, Argyleshire ; Morrone, Braemar, 
Aberdeenshire. Killaloe, co, Clare. 
Form 1. peralbella Nyl. ew Cromb. Journ. Bot. 1876, p. 361.— 
Thallus as in the type. Apothecia small, pale-brownish, slightly 
pruinose ; hymenial gelatine bluish, then wine-red with iodine.— 
