LECAXORA.] LECANO-LEC1DEEI. 369 



Cromb. Lich. Brit. p. 48 ; Leight. Lich. Fl. p. 181, ed. 3, p. 167. 

 Parmelia vitellina ft. corruscuns Ach. Meth. (1803) p. 177. Brit. 

 Exs. : Larb. Lich. Hb. nos. 214, 297, 298 ; Bohl. n. 78. 



The thallus forms a thinnish, continuous or subdiffract crust, and 

 generally spreads somewhat extensively over the substratum. In its 

 more typical state, with the tlialline granules and those of the margin of 

 the apothecia distinctly crenate, it is var. corruscans Ach. Lich. Univ. 

 p. 149 (vide Nyl. Lich. Scand. p. 141). When growing on maritime 

 rocks, both the thallus and apothecia at times give an abnormally 

 brownish-red reaction with K, the result probably of being suffused with 

 salt water. The apothecia are numerous, generally crowded and then at 

 times anguloso-diffjrm, yellow suffused, and often yellow-olivaceous. 



Hab. On rocks, walls, and on the earth in their crevices, also on trees 

 and old pales in maritime, lowland and upland situations. Distr. Gene- 

 ral and common in most parts of Great Britain, the Channel Islands, and 

 no doubt also of Ireland. B. M. : Rozel, Island of Jersey ; Islands of 

 Guernsey and Sark. Near Cromer, Norfolk ; Yarmouth, Suffolk ; Wal- 

 thamstow, Essex ; Dartmoor, Devonshire ; St. Minver, Cornwall ; Ma- 

 dingley, Cambridgeshire ; near Buxton, Derbyshire ; Malvern Hills, 

 Worcestershire ; Longmynd, Shropshire ; Barmouth, Merionethshire ; 

 Island of Anglesea ; near Ayton, Cleveland, Yorkshire ; Alston, Cumber- 

 land ; Staveley, near Kendal, Westmoreland ; Stockstield, Northumber- 

 land. Craigleith, near Edinburgh ; Appin, Argyleshire ; Killin and 

 Blair Athole, Perthshire ; Will's Braes, Forfarshire ; Portlethen, Kin- 

 cardineshire ; Rothiemurchus, Inverness-shire. Near Belfast, co. Antrim ; 

 Kylemore Lake, Connemara, co. Galway. 



Var. ft. aurella Ach. Lich. Univ. (1810) p. 177. Thallus with 

 the granules scattered, often subevanescent. Apothecia minute, the 

 thalline margin entire or at length excluded. Cromb. Lich. Brit, 

 p. 48 ; Leight. Lich. Fl. p. 181, ed. 3, p. 167. Verrucaria aurella 

 Hoffm. Deutsch. Fl. ii. (1791) p. 197. 



Differs from the type, with which it may be confluent, in the less 

 contiguous, more or less obliterated thallus, and in the much smaller 

 apothecia which frequently become biatoroid. 



Hab. On rocks and walls in maritime and upland tracts. Ztistr. 

 Apparently local in the Channel Islands, the S.W. Highlands, and the 

 S. Grampians, Scotland. B. M. : Chateau Point, Island of Sark. Achro- 

 sagan Hill, Appin, Argyleshire ; Killin, Perthshire. 



Subsp. L. xanthostigma Nyl. Not. Sallsk. pro F. & Fl. Fenn. 

 Forh. v. (1866) p. 130. Thallus effuse, thin, subleprose. Apothe- 

 cia small. Cromb. Grevillea, xviii. p. 45. Lecanora xanthostigma 

 Cromb. Journ. Bot. 1832, p. 273. L. citrina ft. xanthostigma Ach. 

 Lich. Univ. (1810) p. 403. Lichen citrinus Eng. Bot. t. 1793 upper 

 fig- 



Characterized by the thinner, more leprose thallus, which at times is 

 somewhat scattered. Nylander observes I. c. that it may be a distinct 

 species. In the fertile British specimens the apothecia are numerous, at 

 length convex, with the thalline margin obliterated. 



2s 



