PLACODIUM | PHYSIACE® 205 
Lecanora xantholyta Ny. in Flora Ixii. p. 361 (1879) ; Cromb., in 
Grevillea vii. p. 112 (1880) & Monogr. i. p. 366. 
Exsicc. Johns. n. 407. 
A leprose condition of Placodiwm. Nylander suggested affinity 
with Pl. cirrochrowm, but Crombie (1. ¢c.) points out that it differs 
from that species in being internally white. 
Hab, On shady calcareous rocks in maritime and upland districts. 
—Distr. Local though plentiful where it occurs in S.W., Central and 
N. England, N. Wales and the Central Highlands, Scotland.—B. M. 
Sidmouth and Anstey’s Cove, Torquay, Devon; Bathampton Downs, 
Somerset; View Edge, Stokesay, Shropshire; Great Orme’s Head. 
Carnarvonshire; Silverdale, Lancashire: Scout Scar, Westmoreland ; 
Craig Tulloch, Blair Athole, Perthshire. 
Thallus not effigurate, efjuse. 
12. Pl. lobulatum A. L. Sni.—Thallus effuse, irregular, thin, 
smooth, sub-areolate, or composed of minute contiguous slightly 
convex lobules, occasionaliy with small lacinie at the circum- 
ference, bright-yellow or orange-red (K + purplish). Apothecia 
small, numerous, plane or convex, concolorous, the margin 
entire ; spores ellipsoid, 10-14 » long, 5-6 p» thick.—Pl. murorum 
var. lobulatum Hepp Flecht. Eur. n. 71 (1855); Mudd Man. 
p- 132: Cromb. Lich Brit. p. 45; var. obliteratum Leight. Lich. 
Fl. p. 176 (1871); ed. 3, p. 161. Lichen obliteratus Pers. in 
Ust. Ann. Bot. xi. p. 15 (1794)? Lecanora lobulata Sommertf. 
Suppl. Fl. Lapp. p. 87 (1826); Cromb. in Grevillea xviii. p. 45 
& Monogr. i. p. 363. 
Exsice. Cromb. n. 156; Johns. n. 72; Larb. Cesar. n. 74 
& Lich. Hb. n. 295; Leight. n. 268. 
A brightly coloured maritime species. which differs from P/. 
murorun in the almost complete absence of peripheral radii. It may 
occur in small or orbicular patches, but is more often irregular and 
wide spreading. Persoon’s species, Lichen obliteratus, is of prior 
date, but its identity is doubtful ; it was collected on calcareous rocks 
and is not recorded as maritime. 
Hab. On rocks in maritime districts.—Distr. Rather common 
round the coasts of the British Isles——B. M. Jersey ; Guernsey: 
Alderney; St. Maws, Cornwall; Isham, and Meadfoot, Torquay, 
Devon; North Cliff, Tenby, Pembrokeshire; Southern Down. 
Glamorganshire ; Barmouth, Merioneth; Great Orme’s Head, Car- 
narvonshire; Anglesea; Douglas, Isle of Man; Arnbarrow, West- 
moreland; St. Bees, Cumberland; Appin, Argyll; Portlethen, Kin- 
cardineshire; Peterhead, Aberdeenshire ; Applecross, Rossshire ; 
Upper Lake, Killarney, Kerry ; Achill Island and Clare Island, Mayo; 
Ardglass, Down. 
13, Pl. miniatulum Oliv. Lich. Eur. p. 92 (1909).—Thallus 
irregular, plane, thin, closely adnate, cracked-areolate, sparingly 
radiate-stellate, deep tawny-vermilion-coloured (K + purplish). 
Apothecia minute, concolorous, the thalline margin entire ; 
