478 LICHEXACEI. [LECANORA. 



Barmouth, Merionethshire ; Trefriw Falls, Carnarvonshire ; Teesdale, 

 Durham. Appin and Glencoe, Argyleshire ; Glen Falloch and Ben Lawers, 

 Perthshire; Glen Callater, Braemar, Aberdeenshire. Ballaghbeama Gap 

 and Dunkerron, co. Kerry ; Connor Cliffit, Dingle, co. Kerry ; Ballynakill 

 and Lough Inagh, Connemara, co. Galway. 



177. L. flavida Hepp, Exs. (1860) n. 030 ; Fr. fil. Vet. Ak. 

 Handl. vii. (1867) p. 24. Thallus effuse, very thin, rimoso-areolate, 

 subleprose, pale ochraceous or glaucous-grey (K , CaCl ). Apo- 

 thecia very minute, innate, at first concave, then plane, black ; the 

 thalline margin thin, entire; spores 8me, ellipsoid, 0,012-18 mm. 

 long, 0,007-11 mm. thick ; paruphyses not discrete, bluish towards 

 the apices : hymenial gelatine deep blue with iodine. Leight. Lich. 

 Fl. ed. 3, p. 195. Aspic-ilia ochracea (non Schaer.) Mudd, Man. 

 p. 163. Lecanora gibbosa forma lacustris Leight. Lich. Fl. ed. 1, 

 p. 210 pro parte. Brit. Exs. : Leight. n. 292 ; Mudd, n. 136. 



A rather inconspicuous plant which, in drv weather, might readily be 

 overlooked, but is well characterized by the characters given. When sub- 

 ochraceous, the black apothecia and the more leprose thallus at once 

 distinguish it from the preceding species ; while the minute fruit, apart 

 from anatomical differences, definitely separates it from the ochraceous 

 state of L. calcarea. The apothecia are usually very numerous. 



Hob. On moist rocks and stones in hilly districts. Distr. Found onlv 

 in N. England. B. M. : Cockshaw Bank, Cleveland, Yorkshire. 



178. L. Prevostii Fr. fil. Lich. Scand. (1871) p. 288. Thallus 

 effuse, very thin, continuous, whitish, greyish- or fleshy-white, often 

 obsolete (K , CaCl ). Apothecia minute, deeply immersed, sub- 

 rotundate or variously diftbrm, concave, carneous or pale-carneous, 

 the proper margin connivent, discrete from the thalline margin ; 

 spores ellipsoid, 0,014-22 mm. long, 0,009-11 mm. thick; para- 

 physes not discrete ; epitheciuin colourless ; hymenial gelatine 

 bluish, then sordidly wine-coloured with iodine. Leight. Lich. Fl. 

 ed. 3, p. 198 ; Cromb. Grevillea, six. p. 58. Lecanora eputoticavar. 

 Prevostii Cromb. Lich. Brit. p. 55 ; Leight. Lich. Fl. ed. 1, p. 212. 

 Gyalecta gzoica Ach. ? Leight. Angio. Lich. t. 15. fig. 1. Gyalecta 

 Prevostii Fr. Lich. Eur. (1831) p. 197. 



At one time regarded by Nylander as a variety of the following species, 

 differing chiefly in the irregular foveolate apothecia. It belongs, how- 

 ever, to this subsection, from the character of the gonidia, \v\i\c\\jide Th. 

 M. Fries (Lich. Scand. p. 289) are 0,009-16 mm. in diameter. In 

 the British specimens the thallus is usually confused with the substratum, 

 whence forma proletaria Fr. fil. /. c. It is then, from the colour of the 

 very small, though numerous, apothecia, a rather inconspicuous plant. 



Hub. On calcareous rocks in upland tracts of hilly and mountainous 

 districts. Distr. Seen from only a few localities in W. and N. England, 

 as also from the Grampians, Scotland. B. M. : Bathampton Downs, 

 Somerset ; Teesdale, Durham ; Levens, Westmoreland. Craig Tulloch, 

 Blair Athole, Perthshire ; Craig Guie, Braemar, Aberdeenshire. 



