lecidea] lecideaceje 51 



p. 263 ; ed. 3, p. 260. Lichen dubius Sm. Engl. Bot. t. 2547 

 (1814). 



The type specimen was renamed by Nylander L. pa/rasema var. 

 fiavens, and another specimen in the Sowerby herbarium was similarly 

 labelled by Crombie. Our specimens form a well connected series in 

 which the surface of the thallus varies from being almost smooth to 

 completely powdery. They also differ from L.parasema in the larger 

 and more crowded apothecia. 



Hab, On old palings. — Dist. Local and not uncommon in the S. 

 of England, extending as far north as Cambridgeshire. — B. M. Near 

 Penzance, Cornwall ; Penshurst, Kent ; Shiere, Surrey ; Ulting and 

 Chalk End, Essex ; Finchley, Middlesex ; Great Comberton, Wor- 

 cestershii-e ; Oakington, Cambridgeshire. 



79. L. sporadiza Stirton in Grevillea iii. p. 33 (1874). — 

 Thallus yellow or greenish-yellow, granular, the granules often 

 conglomerate or pulverulent (K + yellow, CaCl + orange-red). 

 Apothecia black, sessile, small or medium-sized plane, rugose, 

 marginate ; hypothecium colourless ; paraphyses few, irregular, 

 indistinct ; spores ellipsoid, small, 0,006-7 mm. long, 0,004-6 mm. 

 thick ; hymenial gelatine not stained with iodine. — Leight. Lich. 

 n. ed. 3, p. 266, Specimen not seen. 



Said by Stirton to be allied to L. neglecta, but judging from the 

 description its place seems to be here. 



Hab, On old worked wood. Collected by Dr. Stirton near Gran- 

 town, Inverness. 



80. L. parasema Ach. Meth. Lich. p. 35 (1803) pro parte; 

 Nyl. in Bot. Not. (1852) p. 175 & Lich. Scand. p. 217 pro 

 parte. — Thallus determinate or subdeterminate, thin or thinnish, 

 granulose or rather smooth, whitish or grey coloured (K -j- 

 yellowish, CaCl — , K (CaCl) + orange-red) ; hypothallus black, 

 at times limiting the thallus. Apothecia small, at first plane 

 and thinly margined, at length somewhat convex and immar- 

 ginate, black, within blackish, greyish under the epithecium ; 

 paraphyses subcoherent, dark-bluish-green at the apices ; hypo- 

 thecium brownish ; spores ellipsoid, 0,010-16 mm. long, 0,005-8 

 mm. thick ; hymenial gelatine bluish then dark-violet with 

 iodine —Hook, in Sm. Engl. Fl. v. p. 176 (1833) ; Tayl. in 

 Mackay Fl. Hib. ii. p. 119; Mudd Man. p. 200 pro parte; 

 Cromb. Lich. Brit. p. 77 pro parte ; Leight. Lich. Fl. p. 269 ; 

 ed. 3, p. 268. Lichen parasemus Ach. Lich. Suec. Prod. p. 64 

 (1798) pro parte. Lichenoides leprosum, crusta cinereo-virescente, 

 &c.. Dill. Hist. Muse. p. 126, t. 18, f. 3 (1741) pro parte. 



Exsicc. Leight. nos. 308, 327; Johns, nos. 346, 379. 



The species as here understood includes only corticolous forms. 

 Those growing on rocks, formerly considered as varieties, differ con- 

 siderably in the thallus or in the apothecia, and are dealt with under 

 the species that follow. When the thallus is almost or quite 

 evanescent it is var. ecrustacea Leight. Lich. Fl. ed. 3, p. 270. 



E 2 



