420 LICHENACEI. [LECANORA. 
Killin, Perthshire. Near Belfast, co. Antrim; Castleconnell, co. Limerick ; 
Killaloe, co. Clare. 
Var. 8. chondrotypa Stiz. Bot. Zeit. 1868, p. 899.—Thallus as in 
the type. Apothecia convex, often crowded, whitish or subcarneous, 
the thalline margin excluded.—Cromb. Grevillea, xviii. p, 68.— 
Lecanora chondrotypa Ach. Lich. Univ. (1810) p. 365. According 
to Nylander (Lich. Scand. p. 162) this is present in Hb. Acharius 
s. n. Lichen glabratus Dicks., but as Dickson does not record it his 
specific name cannot be retained. 
Differs in the character of the- apothecia, which, however, in a very 
young state are plane with a distinct thalline margin. 
Hab. On the trunks of trees in wooded upland tracts.—Distr. Local 
‘and scarce in 8. England.—B. M.: Bembridge, Isle of Wight; St. Leo- 
nard’s Forest, Sussex ; Lyndhurst, New Forest, Hants ; Ullacombe, Bovey 
Tracey, 8. Devon. 
100. L. glaucoma Ach. Lich. Univ. (1810) p. 362.—Thallus sub- 
determinate, at first continuous, then rimoso-areolate, whitish or 
glaucous-white (K-+yellow, CaOl--); bypothallus thin, whitish. 
Apothecia moderate, innate or appressed, plane or convex, carneous- 
livid or livid-black, casio-pruinose (CaCl + yellow); the thalline 
margin thin or tumid, at length flexuose and obliterated ; spores 
ellipsoid, 0,010-13 mm. long, 0,006-7 mm. thick; paraphyses 
somewhat slender, conglutinate ; hymenial gelatine deep blue, the 
thece violet with iodine.—Hook. Fl. Scot. ii. p. 48; Sm. Eng. Fl. 
vy. p. 189; Tayl. in Mack. Fl. Hib. ii. p.185; Mudd, Man. p. 153 ; 
Cromb. Lich. Brit. p. 50; Leight. Lich. Fl. p. 215, ed. 3, p. 204.— 
Rinodina glaucoma Gray, Nat. Arr. i. p. 453. Lichen glaucoma 
Eng. Bot. t. 2156. Verrucaria glaucoma Hoffm. Deutsch. Fl. ii. 
(1795) p.172. Lichen rupicola (? Linn.) Lightf. Fl. Scot. ii. p. 806 ; 
Hods. Fl. Angl. ed. 2, p. 525; With. Arr. ed. 3, iv. p. 13.—Brit. 
Ews.: Leight. n. 53; Mudd, n. 122; Larb. Lich. Hb. n. 259. 
A very variable plant as to the thallus and apothecia, whence the forms, 
varieties, and subspecies that foll»w. It may, however, always be easily 
recognized by the livid-pruinose apothecia. The thallus, which is rarely 
cesio-greyish, is thickish, more or less expanded, the hypothallus bein; 
visible only in shaded situations at the circumference. It is usually we 
fertile, the apothecia being numerous (at times aggregato-conglomerate), 
with the pruina persistent (forma cinereopruinosa Leight. Lich. Fl. p. 216) 
unless when accidentally rubbed off. The spermogones are frequent, 
black-punctate, immersed, with spermatia arcuate, as in the allied species. 
Both the thallus and the apothecia are the hosts respectively of two dif- 
ferent parasites hereafter to be described. 
Hab. On rocks, boulders, and walls, granitic, schistose, and whinstone, 
in maritime and upland situations, chiefly in mountainous districts. 
Distr. General and common in Great Britain ; no doubt also in Ireland. 
—B.M.: La Moye, Island of Jersey; The Vale, Guernsey; Island of 
Sark. Near Folkestone, Kent; Bolt Head, S. Devon; Valley of Rocks, 
Lynton, N. Devon; St. Minver and Penzance, Cornwall; Bardon Hill, 
