LECANORA| LECANORACEE 287 
Scotland—B. M. Boulay Bay, Jersey; Alderney; Valley of Rocks, 
Lynton, Devon; Barmouth, Merioneth; Keighley and Ayton, York- 
shire; Teesdale, Durham; Craig Tulloch, Blair Athole, Perthshire ; 
Morrone, Braemar, Aberdeenshire. 
32. L. prepostera Nyl. in Flora lvi. p. 19 (1873).—Thallus 
whitish or pale yellowish, rather thick, crowdedly tuberculose 
or smooth and cracked into small areole (K + yellow, then red). 
Apothecia small or moderate in size, at first innate, often poorly 
developed, the dise brown, becoming dull-blackish, generally 
white-pruinose, the thalline margin thick, partly wrinkled or 
crenulate ; paraphyses slender, septate, slightly coloured at the 
tips, but the epithecium dark greenish-brown and granulose ; 
spores rather small, ellipsoid, 9-14 » long, 5-6 p thick; 
hymenial gelatine bluish with iodine.—Cromb. in Grevillea i. 
p. 141 (1873) & Monogr. i. p. 418; Leight. Lich. Fl. ed. 3, 
p- 173. 
The reaction with potash gives a very distinctive character to this 
species, though in some of the specimens it is not very pronounced. 
The thick whitish thallus differentiates it from neighbouring species. 
ee anes with straight or slightly curved spermatia about 16 u 
ong. 
Hab. On basaltic rocks.—Distr. Local and rare in the Channel 
Islands.—B. M. Jerbourg, Guernsey ; Rozel, Jersey. 
Thallus K —. 
33. L. galactina Ach. Lich. Univ. p. 424 (1810).—Thallus 
suborbicular or spreading widely, crustaceous, areolate, the 
granules when well developed crenulate and subsquamulose at 
the circumference, whitish or straw-coloured (K —). Apothecia 
crowded and often obscuring the thallus, rather small, plane, . 
pale brownish-red, white pruinose or naked, the thalline margin 
at first thickish, becoming thin, flexuose and crenulate ; 
hymenium inspersed-granulose ; paraphyses slender, septate, 
sometimes wider at the tips; spores ellipsoid, 9-15 yp long, 
5-7 p thick ; hymenial gelatine blue with iodine.—Mudd Man. 
p. 149 (excl. var. disperso-areolata) ; Cromb. Lich. Brit. p. 50 & 
Monogr. i. p. 404; Leight. Lich. Fl. p. 206; ed. 3, p. 189. 
Lichenoides crustosum, orbiculare incanum Dill. Hist. Muse. p. 135, 
t. 18, fig. 17 B (1741). Parmelia galactina Ach. Meth. Lich. 
p. 190 (1803). 
Exsicc. Johns. n. 236; Larb. Lich. Cantab. n. 26; Leight. n. 
400; Mudd n. 116. 
A very variable lichen in the grouping of the apothecia and in the 
appearance of the thallus. The latter begins in small orbicular 
patches, with the outer granules somewhat spreading and lobate, but 
it soon spreads and becomes irregular and indeterminate, and is often 
obscured by the numerous apothecia, which become angular from 
pressure. It is one of the few lichens that persists in the immediate 
neighbourhood of large towns. 
