LECANORA.] LECANO-LECTDEEI. 435 



Yar. ft. aitema Nyl. Flora, 1873, p. 229. Thallus somewhat 

 thickish, leprose, bright yellow. Apothecia small or submoderate, 

 convex, lecideoid, black ; spores 0,012-17 mm. long, 0,0045-55 

 mm. thick. Cromb. Grevillea, xviii. p. 69. Lecanora varia var. 

 aitema Cromb. Lich. Brit. p. 52; Leight. Lich. Fl. p. 192. L.sym- 

 micta var. aitema ed. 3, p. 183. Lecidea aitema Ach. Lich. Univ. 

 (1810) p. 178. Lecanora varia . denigrata (non Fr.), Mudd, Man. 

 p. 151. Brit. Exs. : Cromb. n. 66 ; Larb. Lich. Hb. n. 255 : 

 Mudd, n. 118. 



Looks entirely as if a Lecidea, near L. parasema. It is, however, 

 only a variety of this species, with which it agrees in the reactions, but 

 differs in the more leprose thallus and the colour of the apothecia. The 

 thallus at times occurs in small determinate macula? and is alwaj's well 

 fertile, the apothecia being colourless within. A state in which there 

 are few or no traces of a thallus, with the apothecia crowded and often 

 less convex, is form depauperata Oromb. Grevillea I. c. 



Hob. On old palings in upland districts. Distr. Not infrequent in Great 

 Britain ; not seen from Ireland or the Channel Islands. B. M. : Near 

 Lyndhurst, New Forest, Hampshire ; Shanklin, Isle of "Wight ; Dart- 

 moor, S. Devon ; near Millhill, Middlesex ; near Gamlingay, Cambridge- 

 shire ; Battersby, Cleveland, Yorkshire ; Alston, Cumberland. Finlarig, 

 Kenmore, and Glen Lyon, Killin, Glen Fender, Blair Athole, Perth- 

 shire ; Crathie, Braemar, Aberdeenshire ; Rothiemurchus, Inverness-shire. 



121. L. trabalis Nyl. Flora, 1877, p. 458. Thallus effuse, 

 glebuloso-granulate, subverrucoso-diffract, thinnish or submoderate, 

 greyish (K + yellowish, CaCl ). Apothecia small, adnate, some- 

 what convex, immarginate, pale-livid, sordidly pale-testaceous or 

 livid-blackish ; spores rarely spuriously 1-septate, oblong, 0,009- 

 0,014 mm. long, 0,0035-45 mm. thick ; epithecium granulose, 

 paraphyses slender ; hymenial gelatine bluish, then subincolorous 

 (the thecae subpersistently bluish) with iodine. Lecidea scepincola 

 var. trabalis Ach. Syn. (1814) p. 35. 



Allied to L. symmictera, of which Nylander I. c, says it may perhaps 

 be a subspecies. In the British specimens, one of which was recently 

 determined by him, the thallus is chiefly dark-grey from age. The 

 apothecia are numerous and often diff or mi- connate. 



Hab. On a decorticated stump of hornbeam oak in a wooded upland 

 tract. Distr. As yet only sparingly in E. England. B. M. : Highbeech, 

 Epping Forest, Essex. 



122. L. piniperda Koerb. Par. Lich. (1865) p. 81. Thallus 

 effuse, thin, verruculoso-leprose, whitish (Kf-f- yellowish, CaCl ). 

 Apothecia minute, plane or convex, subcarneous or brownish, 

 pruinose, the thalline margin pale, thin, entire, or subcrenulate, at 

 length excluded : spores oblongo-ellipsoid, 0,008-12 mm. long, 

 0,004-5 mm. thick ; hymenial gelatine deep blue, then tawny with 

 iodine. Cromb. Journ. Bot. 1873, p. 133 ; Leight, Lich. Fl. ed. 3, 

 p. 174. Brit. Exs. : Leight. n. 176 ; Cromb. n. 160. 



