564 CYCLOCARPINE [PERTUSARIA 
12. P. melanochlora Nyl. in Bull. Soc. Linn. Norm. sér. 2, 
vi. p. 289 (1872).—Thallus effuse (or determinate), tartareous, 
thick, wrinkled and warted, subareolate, densely papillate, the 
papill short, stout, rounded and sometimes sorediate at the apex, 
greyish-white or greyish-smoke-coloured (K(CaCl) = violet-rose- 
coloured). Apothecia small, several (2—5) in the sorediate papille ; 
spores | in the aseus, 180-250 p long, 75-100 p» thick.—Cromb. 
in Grevillea xix. p. 59 (1891) & Monogr. i. p. 493. Isidium 
melanochlorum DC. Fl. Fr. ii. p. 326 (1805). 
The chemical reaction is distinct in Nylander’s specimen from the 
Pyrenees; it is very slight in the one from Wales. The spores are 
very thick-walled and taper downwards, perhaps a development stage, 
and, so far as observed, measure from 45 » in width. The spermatia 
(fide Nyl.) measure about 4-5 p» long, 1 p thick. 
Hab. On quartzose and schistose rocks. — 6B. M. Barmouth, 
Merioneth (the only British record). 
B. Spores usually two in the ascus. 
Thallus non-sorediate ; spores colourless. 
13. P. pustulata Ny]. in Act. Soc. Linn. Bord. sér. 3, 1. p. 441 
(1856) (? Leight. Angioc. Lich. p. 30, t. 10, fig. 4 (1851) ).— 
Thallus developed beneath or above the bark, determinate, thinnish, 
smooth or finely granulate in parts, cream-coloured or greyish- 
white (K + yellowish, K(CaCl) + slightly reddish). Apothecia 
solitary or several in small convex scattered or congregate verrucer, 
the ostioles punctiform and dark, then becoming lacerate and 
exposing a small flesh-coloured open disc ; spores 2 in the ascus, 
60-126 p long, 25-45 p thick.—Mudd Man. p. 275 pro parte ; 
Cromb. Lich. Brit. p. 60 pro parte & Monogr. i. p. 504; Leight. 
Lich. Fl. p. 244; ed. 3, p. 234 pro parte. \P. melaleuca Dub. 
Bot. Gall. ii. p. 673 (1830); Leight. Angioc. Lich. p. 29, t. 10, 
fig. 4 & Lich. Fl. p. 240; ed. 3, p. 230; Mudd Man. p. 275; 
Cromb. Monogr. i. p. 504. Porina pustulata Ach. Lich. Univ. 
p- 309 (1810). Lichen melaleucus Sm. Engl. Bot. t. 2461 (1813). 
Thelotrema melaleucum Turn. & Borr. ex Sm. |. c. & Lich. Brit. 
p. 183; Hook. in Sm. Engl. Fl. v. p. 161. 
Characterized by the thin smoothish thallus and by the 2-spored 
ascus. The reaction with potash is most easily seen in sections 
under the microscope, with calcium hypochlorite added the thallus 
is generally tinged reddish. There is no specific distinction between 
P. pustulata and P. melaleuca; several British specimens classified 
by Crombie and others as P. pustulata belong to P. communis or to 
P. leioplaca. In a specimen from Dolgelly the verruce are whitish 
on a grey thallus; it has been determined by Crombie as f. super- 
pallens Nyl. (Flora Ixix. p. 466 (1886) ). 
Hab. On trees in wooded districts.— Distr. Rather rare in the 
southern and midland counties of England and in N. Wales.—B. M. 
New Forest, Hants; tArdingly and St. Leonard’s Forest, Sussex ; 
