492 LICHENACET. [PERTUSARIA. 
Soc. Cherb. iti. p. 180.—Thallus continuous, verrucoso-unequal, or 
smoothish, very rarely hypoplilcodal. Apothecia endocarpoid or 
lecanoroid; spores 1l—4ne, 6-8ne, 
large, ellipsoid or oblong, colourless, 
rarely blackish, with a thick or 
thickish epispore ; parapbyses lax or 
coherent, variously branched and 
arcuate; hymenial gelatine, but chiefly 
the thecs, deep-lilac with iodine. 
Spermogones with acicular, straight 
spermatia. 
A natural and well-defined genus, 
most of the European species of which 
occur in our Islands, where also one or 
two seem to be endemic. Several of the 
plants included in it frequently occur 
only in a variolarioid or isidioid state, 
constituting the pseudogenera Variolaria 
and Isidiwm of older authors. A few of 
these enumerated by Turner and Borrer 
in their ‘Lichenographia Britannica’ 
and subsequently figured in Eng. Bot. 
Suppl., being very doubtful, are here 
omitted. 
A. Thecz pauci-spored ; spores colour- 
less. 
a. Spores solitary. 
1. P. bryontha Nyl. Lich. Scand. 
(1861) p. 178; Flora, 1881, p. 538. 
—Thallus effuse, thin, subgranulato- 
unequal, white or whitish, white-sore- 
diose (K+ yellowish, soredia CaCl+ 
reddish), Apothecia lecanorine, mode- 
xe250 
rate, at first urceolate, then subplane, Fig. 70. 
prominent or substipate, opaque, Pertusaria communis DC.— 
sordidly liver-coloured, or sordid- A 2-spored theca and para- 
brownish, the thalline margin at pbreet ys 208 
length depressed or excluded; spores 0,150-0,230 mm. long, 
0,050-70 mm. thick—Cromb. Lich. Brit. p. 58; Leight. Lich. Fl. 
p- 240, ed. 3, p. 230.—Parmelia subfusca B. bryontha Ach. Meth. 
(1803) p. 167. Pertusaria macrospora Hepp, Mudd, Man. p. 277. 
Looks almost a state of Lecanora epibrya, but is very different in the 
structure of the fruit and the form of the spermatia, The apothecia, 
which are at first pale, are in our few specimens at times somewhat 
crowded. It is one of our rarest British lichens. 
Hab. On the ground, encrusting mosses and decayed Carices, in alpine 
places.—Disér. Extremely local and scarce on one or two of the N. 
Grampians, Scotland.—B. M.: Cairngorm and Ben-naboord, Braemar, 
Aberdeenshire. 
