PERTUSARIA | PERTUSARIACEX ane 
Hab. On rocks in maritime and mountainous regions.—Distr. 
Rather rare in Wales, N. England, S.W. Highlands of Scotland and 
S. and W. Ireland.—B. M. Dolgelly, Merioneth; Anglesea; Ingleby 
Park, Cleveland, Yorkshire; Lismore, Argyll; The Trossachs, Perth- 
shire ; Dunkerron, Kerry; Belclare and Corraun Mt., Achill, Mayo. 
31. P. gyrocheila Nyl. in Flora xlviii. p. 354 (1865).—Thallus 
effuse or determinate, unequally granulate, deeply cracked, grey 
(K + yellow, CaCl —). Apothecia in prominent tubercles, simple 
or becoming subgyrose, with the disc labyrinthine (glypholeceine) ; 
spores 8 in the ascus, 68-70 w long, 36-50 » thick; hymenial 
gelatine and asci bluish with iodine.—Carroll in Journ. Bot. iv. 
p. 23 (1866); Cromb. Lich. Brit. p. 61 & Monogr. i. p. 509; 
Leight. Lich. Fl. p. 241; ed 3, p. 232. 
The above description is taken from Nylander. Of the two 
specimens in the British herbarium from rocks, Ben Lawers, deter- 
mined as P. gyrocheila, one may be perhaps considered a co-type, as 
it presumably forms part of the original collection; the other, also 
from Ben Lawers, was collected by Crombie. The material is too 
scanty to permit of exhaustive examination, but, as far as can be 
judged, they are very weathered exposed forms of Lecanora tartarea 
with exactly the same thalline reaction and the same size of spores 
as in that species. A series of somewhat similar specimens collected 
by the late W. West in Shetland and the Outer Hebrides were at 
first determined as Pertusaria gyrocheila, but finally were proved to 
be Lecanora tartarea, with transition stages from a normal open dise 
to a gyrose apothecium. 
57. VARICELLARIA Nyl. in Mém. Soc. Sci. Nat. Cherb. v. 
p. 117 (1857); Lich. Scand. p. 182. (PI. 57.) 
Thallus thinly crustaceous, corticate. Apothecia in convex 
verruce, deeply immersed ; paraphyses slender, branched, intricate ; 
asci l-spored ; spores very large, ellipsoid, 1-septate, colourless. 
Spermogones unknown. 
According to Darbishire (Engl. Bot. Jahrb. xxii. p. 631 (1897) ) 
there is generally a cortex of plectenchyma about two cells thick both 
above and below. Strong hyphe traverse the internal tissue, uniting 
the two cortices, while from the lower cortex rhizine are produced, 
which attach the thallus to the substratum. 
1. V. microsticta Nyl. ll.c.—Thallus subdeterminate, unequal, 
thin, smooth, sometimes isidiose or leprose, whitish (K —, CaCl —). 
Apothecia usually solitary in the fertile verrucs, of which several 
may be confluent, at first immersed then opening, the disc pale- 
reddish or flesh-coloured, generally white-suffused from the breaking 
down of the overlying tissues, the margins also suffused ; spores 
very large, 225-350 w long, 95-115 w thick; hymenial gelatine 
and asci deep-blue with iodine.—Cromb. in Journ. Bot. xx. p. 272 
(1882) & Monogr. i. p. 511. 
Sufficiently distinguished by the 2-celled enormous spore, the 
largest known in lichens. When poorly developed it resembles 
