PERTUSARIA. ] LECANO-LECIDEEI. 503 
Hab. On trunks of old trees in upland districts —Distr, Only here and 
tkere throughout England; not seen in Scotland or Ireland.—B. M.: 
Near Norwich, Norfolk; near Quendon, Epping and Hainault Forests, 
Essex ; Albourne, Sussex; New Forest, Hautes Salporton, Gloucester- 
shire; Hay Park, Herefordshire; Baysdale, Cleveland, Yorkshire. 
Form bacillosa Nyl. ew Lamy, Bull. Soc. Bot. t. xxv. (1878) 
p- 425.—Thallus covered with numerous, long, isidioid papille 
which are obtuse and branched.—Cromb. Grevillea, xix. p. 59. 
Only a very luxuriant though well-marked condition of the type. It 
is always sterile. 
Hab. On the trunk of an old tree in a wooded upland situation.— 
Distr. Only very sparingly in S. England—B. M.: Near Lyndhurst, 
New Forest, Hants. 
17. P. concreta Nyl. Mém. Soc. Cherb. v. (1857) p. 117; Flora, 
1876, p. 234.—Thallus determinate, continuous, thickish, rimose, 
unequal, white or whitish, subeffigurate at the circumference 
(K “a yellow, then saffron-red). Apothecia immersed in convex, 
variously confluent, thalline verruce, endocarpoid, colourless, 
indicated externally by a dark punctiform ostiole; spores 0,015- 
25 mm. long, 0,052-080 mm. thick.—Cromb. Grevillea, vy. p. 25; 
Leight. Lich. Fl. ed. 3, p. 227. 
A rather interesting plant, forming, as observed by Nylander (Flora, 
l.c.), the typical condition of “ Istdium Westringw,” the relation of 
which to the allied species had previously been very uncertain. On the 
thallus of the Irish specimens, which are well fertile, traces occur here 
and there of a few short abortive papillee. 
Hab. On schistose rocks in a maritime district.—Distr. Extremely 
local and scarce in N.W. Iveland.—B. M.: Letterfrack, Connemara, co. 
Galway. 
Form Westringii Nyl. Flora, 1876, p. 234.—Thallus more or 
less densely papillose; papilla at first minute, subglobose, then 
elongate, subcylindrical, simple and branched, brown at the apices. 
Cromb. Grevillea, xix. p. 59.—P. Westringii Leight. Lich. Fl. 
p. 236, ed. 3, p. 227 pro minima parte. Lichen Westringii Ach. 
Vet. Ak. Handl. 1794, p. 179, t. 6. f. 1; Eng. Bot. t. 2204; Dicks, 
Crypt. fase. iv. p. 20. Isidium Westringizt Turn. & Borr. Lich. Br. 
p. 92; Gray, Nat. Arr. i. p. 412; Hook. FI. Scot. ii. p. 66; Sm. 
Eng. Fl. v. p. 239. 
Only a sterile isidioid condition, though at first sight appearing very 
distinct. The papille are sometimes 2-3 confluent, and in age the apical 
globules become dark- or reddish-brown. 
Hab. On rocks and walls in maritime and mountainous districts.— 
Distr. Here and there throughout Great Britain; rare in the Channel 
Islands and W. Ireland; probably often overlooked.—B, M.: Island of 
Guernsey. Near St. Austell and Penzance, Cornwall; Barmouth and 
Aberdovey, Merionethshire; Arkendale, Durham; Thornthwaite, near 
