396 LICIIENACEI. [LECANORA. 



Hal>. On trees, old pales, rocks, walls, and tiled roofs in maritime, 

 lowland and upland districts. Distr. Not uncommon in England and 

 the Channel Islands ; apparently rare in N.E. Scotland, E. and N.W. 

 Ireland, though probably often overlooked in both these countries. B. M. : 

 Noirmont, Island of Jersey ; Chateau Point, Island of Sark ; The Vale, 

 Guernsey. Yarmouth, and near Brandon, Suffolk ; Epping Forest, Essex ; 

 Hurstpierpoint, Sussex ; Shanklin, Isle of Wight ; Lyndliurst, New Forest, 

 Hants ; near Bristol, Somersetshire ; Charfield, Gloucestershire ; near 

 Worcester ; Weston, Oxfordshire ; near Oswestry, Shropshire ; Barmouth, 

 Aber-ty-Gyn, N. Wales ; Port Soderick, Isle of Man ; near Newton, 

 Cleveland, Yorkshire : St. Bees, Cumberland. Portlethen, Kincardine- 

 shire. Portmaronock, near Dublin ; Kylemore and Cleghan, Connemara, 

 co. Galway. 



Form demissa Stiz. St. Gall. Nat. Ges. 1822, p. 359. Thallus 

 thin, leproso-granulose, greenish-brown or pale, often evanescent. 

 Apothecia minute, somewhat prominent, the thalline margin at 

 length obliterated. Cromb. Grevillea, xviii. p. 46. llinodina meta- 

 bolica ft. demissa Kcerb. Syst. Lich. Germ. (1885) p. 124. 



Distinguished by the colour of the thallus, and more especially by the 

 minute, emersed, at length immarginate apothecia. In the very few 

 British specimens these are numerous and here and there crowded. 



Hob. On rocks in maritime tracts. Distr. Only sparingly in S. Eng- 

 land. B. M. : Shanklin and near Luccombe, Isle of Wight. 



Var. ft. lecideoides Cromb. Grevillea, xviii. (1889) p. 46. 

 Thallus very thin, macular, greyish-white, usually evanescent. 

 Apothecia small, lecideine, black or blackish, the margin dark- 

 brown, at length obliterated ; spores 0,016-20 mm. long, 0,008-11 

 mm. thick. Lecanora sophodes var. lecideoides Nyl. Lich. Scand. 

 (1861) p. 149; Leight. Lich. PI. p. 225, ed. 3, p.'215 pro minima 

 parte. 



Might readily be taken on a cursory inspection for Lecidea myriocarpa, 

 as observed by Nylander /. <?., but differs at once in the colour of the 

 margin of the apothecia and in the whitish hypothecium. He also sug- 

 gests that it probably descends from Lecanora confragosa, with which it 

 agrees rather than with L. exigua in the size of the spores. The absence, 

 however, of any reaction with K connects it with the present species. 

 The thallus is but little visible in the few British specimens. 



Hab. On old palings in an upland situation. Distr. Apparently only 

 among the S. Grampians, Scotland. B. M. : Glen Lochay, Killin, Perth- 

 shire. 



62. L. subexigua Nyl. Flora, 1874, p. 308. Thallus effuse, 

 subsmooth, unequal, rimose, pale-greyish or sordid-yellowish (K , 

 CaCl ). Apothecia minute, plane, black, the thalline margin 

 thickish, entire; spores 0,012-15 mm. long, 0,006-7 mm. thick. 

 Cromb. Grevillea, iii. p. 22 ; Leight. Lich. Fl. ed. 3, p. 220. 



Subsimilar to the preceding species, but differs in the characters of the 



