420 LICHENACEI. [leCANORA. 



Killin, Perthshire. Near Belfast, co. Antrim ; Castleconnell, co. Limerick ; 

 Killaloe, co. Chare. 



Var. /3. chondrotypa Stiz. Bot. Zeit. 1868, p. 899.— Thallus as in 

 the type. Apothecia convex, often crowded, whitish or subcariieous, 

 the thalline margin excluded.— Cromb. Grevillea, xviii. p. 68.^ — ■ 

 Lecanora chondrotypa Ach. Lich. Univ. (1810) p. 365. According 

 to Nylander (Lich. Scand. p. 'ii'i2) this is present in Hh. Acharius 

 s. n. Lichen glubratus 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. 



Hah. On the trunks of trees in wooded upland tracts. — Distr. Local 

 and scarce in S. England. — B. M. : Bembridge, Isle of Wight ; St. Leo- 

 nard's Forest, Sussex ; Lyndhurst, New Forest, Hants ; UUacombe, Bovey 

 Tracey, S. Devon. 



100. L. glaucoma Ach. Lich. Univ. (1810) p. 362.— Thallus sub- 

 deterrninate, at first continuous, then rimoso-areolate, whitish or 

 glaucous-white (K -(-yellow, CaCl — ); hypothallus thin, whitish. 

 Apothecia moderate, innate or appressed, plane or convex, carneous- 

 livid or livid-black, csesio-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 

 thecte violet with iodine. — Hook. Fl. Scot. ii. p. 48 ; Sm. Eng. Fl. 

 V. p. 189 ; Tayl. in Mack. Fl. Hib. ii. p. 135 ; Mudd, Man. p. 153 ; 

 Cromb. Lich. Brit. p. 50 ; Lcight. Lich. Fl. p. 215, ed, 3, p. 204. — 

 Rinodina glaucoma Gray, Nat. Arr. i. p. 453. Lichtn glaucoma 

 Eng. Bot. t. 2156. Verrucaria glaucoma Hoffm. Deutsch. Fl. ii. 

 (1795) p. 172. Liclien rupicola (? Linn.) Lightf. Fl. Scot. ii. p. 806 ; 

 Huds. Fl. Angl. ed. 2, p. 525; With. Arr. ed. 3, iv. p. \^.—Brit. 

 Exs. : Leight. n. 53 ; Mudd, u. 122 ; Larb. Lich. Hb. n. 259. 



A verj' variable plant as to the thallus and apothecia, whence the forms, 

 varieties, and subspecies that foll.uv. It may, however, always be easily 

 recognized by the livid-pruinose apothecia. The thallus, which is rarely 

 caesio-greyisli, is thickisli, more or less expanded, the hypothallus being 

 visible only in shaded situations at the circumference. It is usually well 

 fertile, the apothecia being numerous (at times aggregato-conglomerate), 

 with the pruina per.-istent (forma cinereopruinosa Leight. Lich. 11. p. 216) 

 unless when accidentally rubbed off. The spermogones are frequent, 

 black-punctate, inmiersed, 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 siiuations, chiefly in mountainous districts. — 

 Distr. General and common in Great Britain ; no doubt also in Ireland. 

 — B. M. : La Moye, Island of .lersey ; The Vale, Guernsey ; Island of 

 Sark. Near Folkestone, Kent ; Bolt Ilead, S. Devon ; ^■ alley of Eocks, 

 Lvnton, N. Devon; St. Minver and I'en/ance, Cornwall; IJardon Hill, 



