496 LICHENACEL. [PERTUSARIA. 
Lich. Br. p. 59; Gray, Nat. Arr. i. p. 490; Sm. Eng. FI. v. p. 169. 
Lichen globuliferus Eng. Bot. t. 2008. Lichenoides candidum et 
farinaceum, scutellis fere planis Dill. Muse. 131, t. 18. f. 11 B— 
Brit. Exs.: Mudd, n. 263 pro parte. 
The thallus, which usually spreads extensively, is somewhat depressed 
at the circumference, where it presents zones of various shades, chiefly 
brown and carneous. The fertile verruce, of which the form and 
ultimate development are aptly described by Turner aud Borrer, /. ¢., are 
not of common occurrence and are usually but few on the same plant. 
More frequently the verruce are sterile, plane, with a thickish margin and 
densely white-sorediate having a lecanoroid appearance. In this abortive 
condition of the apothecia, which at times occurs on the same plant as 
their normal state, it is form discoidea Cromb. Grevillea, xix. p. 59; 
Lichen discoideus Eng. Bot. t.1714; Variolaria discoidea Turn. & Borr. 
Lich. Br. p. 61, Sm. Eng. Fl. v. p. 168, Tayl. in Mack, Fl. Hib. ii. p. 112, 
Dill. 7. ce. f£. 11 C. 
Hab, On trunks of old trees in wooded maritime and upland districts. 
— Distr. General and common where it occurs in Great Britain ; appa- 
rently rare in Ireland. 3B. M.: Yarmouth, Norfolk; Epping Forest, 
Essex; Penshurst, Kent; Shiere, Surrey; St. Leonard’s Forest and 
Danny, Sussex; New Forest, Hants; Chudleigh and Beckey Falls, 
8. Devon; Boconnoc and near Withiel, Cornwall; Savernake Forest, 
Wilts; Cirencester, Gloucestershire; Madingley, Cambridgeshire; Charn- 
wood Forest, Leicestershire; Mulvern, Worcestershire; Lambeth, S. 
Wales; Barmouth, Merionethshire; Island of Anglesea; Craig-y-Rhiw 
and Haughmond Hill, Shropshire; near Ayton, Cleveland, Yorkshire ; 
Teesdale, Durham. Helensburgh, Dumbartonshire; Inverary and by 
Loch Creran, Argyleshire; Craigforth, Stirling; Glen Lochay, Killin, 
and Blaeherry Hill, near Perth, Perthshire; Murtle, near Aberdeen; by 
Loch Linnhe, Inverness-shire. Castlemartyr and Macroom demesne, 
co. Cork; Ashley Park, near Galway. 
8. P. ophthalmiza Nyl. Flora, 1865, p. 354.—Thallus effuse, 
thin, smoothish, or slightly rugoso-unequal, greyish (K—, CaCl—) ; 
fertile verruce small, more or less crowded. Apothecia 1, rarely 
2-8 in each verruca, lecanoroid, blackish, crowned with a rugose or 
subleprose thalloid margin; spores 0,160-205 mm. long, 0,080- 
100 mm. thick.—Carroll, Journ. Bot. 1866, p. 23; Leight. Lich. 
FI. p. 242, ed. 3, p. 233.—P. globulefera subsp. ophthalmiza Cromb. 
Lich. Brit. p. 59; var. ophthalmiza Nyl. Lich. Scand. (1861) p. 180. 
Well distinguished from the preceding, to which it has a superficial 
resemblance, by the form of the fructification. It spreads extensively, 
though interruptedly, over the substratum with no visible circumferential 
line. The fertile verrucee are usually numerous, at times almost oblite- 
rating the rest of the thallus, 
Hab. On the trunks of aged pines in an upland district Distr, Only 
sparingly in the S.W. Highlands of Scotland.—B. M.: Glen Falloch, 
and Black Wood, Rannoch, Perthshire. 
9. P. amara Nyl. Flora, 1873, p. 22.—Thallus determinate, 
rugoso-rimose, unequal, subpulverulent, greyish-white, brown and 
zonate at the circumference (K—, CaCl—). Apothecia white- 
