494 LICHENACEI. [PERTUSARA, 
A well-marked species readily recognized, even when sterile, by the 
peculiar thalline papille. The apothecia, recently described by Nylander, 
from plants gathered in the FE. Pyrences, are seldom rightly developed in 
the few British specimens. The spermogones, also rare in these, have 
the spermatia bacillar, about 0,004-5 mm. long, scarcely 0,001 mm. thick 
(fide Nyl.). 
Hab. On quartzose and schistose rocks in a mountainous region.— Distr. 
Seen cnly sparingly from N. Wales.—B. M.: Barmouth, Merionethshire. 
5. P. monogona Nyl. Flora, 1873, p. 71.—Thallus subdeter- 
minate, rugose, areolatu-rimose, greyish-white (K cs yellow): thew 
saffron-orange). Apothecia at first innate in the areole, then 
somewhat prominent, the thalline margin entire or subcrenate; 
epithecium dilated, brownish, uneven, white-pulverulent ; spores 
oblongo-ellipsoid, 0,150-2385 mm. long, 0,070-80 mm. thick— 
Cromb. Grevillea, xix. p. 59. 
Nylander /. c. says that this is subsimilar to P. dealbata, from which it 
at once differs in the monospored thee. The other characters given 
sufficiently distinguish it from this and other British Pertusarias. In 
our specimens the fertile verrucee are numerous and here and there 
crowded. The spermogones are not infrequent, with spermatia about 0,004 
mm. long, nearly 0,001 mm. thick. 
Hab. On schistose rocks in a mountainous region.— Distr. Extremely 
local and scarce in N. Wales—B. M.: Cader Idris, Merionethshire. 
6. P. multipuncta Nyl. Not. Sillsk. pro F. et Fl. Fenn. Forh. xi. 
(1870) p. 185.—Thallus determinate or subdeterminate, thinnish, 
granulato- or rugoso-unequal, rimose, whitish or greyish-white ; 
fertile verruce small, prominent, usually white-sorediate (K—, 
CaCl—, I + dark-bluish). Apothecia usually numerous in each 
verruca, pale or blackish, cesio-pruinose, at length naked; spores 
oblong or lineari-oblong, 0,106-140 mm. long, 0,028-68 mm. thick. 
—Cromb. Grevillea, xix. p. 59.—FPertusaria multipunctata Leight. 
Lich. Fl. p. 236, ed. 3, p. 226. P. globulifera 8. multipunctata 
Mudd, Man. p. 274; Cromb. Lich. Brit. p.59. Variolaria multi- 
puncta Turn. Trans. Linn. Soc. ix. (1808) p. 187, t. 10. f. 1; Turn. 
& Borr. Lich. Br. p. 73; Gray, Nat. Arr.i. p. 490; Sm. Eng. FI. v. 
p. 170. Lichen multipunctus, Eng. Bot. t. 2061.—A saxicolous 
state is Pertusaria sublactea Leight. Ann. Mag. Nat. Hist. 1870, vi. 
p. 474; Lich. Fl. p. 245, ed. 3, p. 236 (cfr. Nyl. Flora, 1883, 
p. 5384).— Brit. Zxs.: Mudd, n. 262. 
Has often externally the aspect of some Phlyctis, as noticed by Th. M. 
Fries (Lich. Scand. p. 809). From the other species of the genus it is 
well separated by the more elongate spores. The verruce are usually 
very numerous, though distinct, each with from 1 to 12 apothecia. The 
thalline reaction with K is erroneously given by Leighton, there being 
pay visible at times a very faint yellow tinge immediately passing into 
own. 
