474 LICHENACE1. [LECANORA. 
carea Mudd, Man. p. 161,t. 3. £.55. Urceolaria calearea Sm. Eng. 
Fl. v. p. 172; Tay]. in Mack. Fl. Hib. ii. p. 132; Gray, Nat. Arr. 
ip. 459. Lichen calcareus Linn. Sp. Pl. (1753) p. 1140; Huds, 
Fl. Angl. p. 442; With. Arr. ed. 3, iv. p. 6 pro minima parte. 
Lichen tessellatus Eng. Bot. t.553. Urceolaria tessellata Ach., Gray, 
Nat. Arr. i. p. 460.— Brit. Evs.: Leight. n. 13; Mudd, n. 1838; 
Larb. Lich. Hb. n. 166. 
Easily recognized among British species by the whitish or chalky- 
white thallus, In its more typical condition it is a. concreta (Schaer. 
Spicil. p. 73) Leight. Lich. Fl. ed. 3, p. 192 (tessellata, Ach.), with the 
thallus determinate, often subetfigurate at the circumference, and the 
areole contiguous, angulose. The apothecia are numerous, often crowded, 
at times naked, with the proper margin at length discrete from the 
thalline margin. The spermogones are frequent, dark-brown or blackish, 
with spermatia aciculari-cylindrical, 0,007-9 mm. long, about 0,001 mm. 
thick. 
Hab. On calcareous rocks and walls, rarely granitic, in maritime and 
upland districts—Distr. General and common in limestone tracts of 
Great Britain and Ireland ; not seen from the Channel Islands.—B. M.: 
Burgh Castle, Suffolk; Peasemarsh, Sussex; Plymouth, 8. Devon; near 
Penzance, Cornwall; Bathampton Downs, Somerset; Cunning Dale, 
near Buxton, Derbyshire; Malvern Hills, Worcestershire ; Barmouth, 
Merionethshire ; Great Orme’s Head, Carnarvon; Island of Anglesea; 
Bilsdale, Yorkshire; Eglestone and Teesdale, Durham; Levens, West- 
moreland. Appin and Island of Lismore, Argyleshire; Craig Tulloch, 
Blair Athole, Perthshire ; Morrone, Braemar, Aberdeenshire. Dunkerron, 
co. Kerry ; Maam, Connemara, co. Galway. 
Var. 3. contorta Nyl. Flora, 1872, p. 554.—Thallus effuse, 
white or greyish-white, the areole more or less discrete, elevated 
in the centre, depressed and at times subeffigurate at the circum- 
ference. Apothecia immersed.—Leight. Lich. Fl. ed. 3, p. 193.— 
Aspicilia calearea B. contorta Mudd, Man. p. 162. Urceolaria 
contorta Tayl. in Mack. Fl. Hib. ii. p. 182. Lichen contortus Hoffm. 
Deutsch. Fl. ii. (1795) p. 186.—Brit. Evs.: Leight. n. 322. 
Distinguished by the form of the discrete or subdiscrete thalline 
areola. It usually spreads extensively over the substratum and is well 
fertile. 
Hab. On calcareous rocks in maritime, but chiefly upland districts.— 
Distr. Somewhat local in Great Britain and Ireland.—B. M.: Near 
Kingskerswell, 8S. Devon ; Symmond’s Yat, Herefordshire ; Ashwood Dale, 
Derbyshire; near Oswestry, Shropshire ; Great Orme’s Head, Carnarvon- 
shire; Teesdale, Durham. The Ochils, near Stirling; Craig Tulloch, 
Blair Athole, Perthshire; Craig Guie, Braemar, Aberdeenshire. The 
O’Donoghue’s Prison, Killarney, co. Kerry. 
Form monstrosa Cromb. Grevillea, xix. (1891) p. 57.—Thallus 
effuse, snow-white ; areole discrete, scattered, rounded, convex, 
entire at the margins, Apothecia abortive, minute, deeply im- 
mersed.—ZL. calcarea var. monstrosa Lamy, Bull. Soc. Bot, t. xxx. 
(1883) p. 392. 
