LECIDEA] LECIDEACEiE 91 



Distinguished from L. tenebrica by the larger margined apothecia 

 and by the chemical reactions. 



Hab. On schistose rocks, sparingly, Red Screes, Westmoreland. 



160. L. g^riseoatra Schrer. Enum. p. 101 (1850).— Thallus 

 subdeterminate, tliinnish or submoderate, somewhat smooth, 

 opaque, rimose-areolate or areolate-granulose, dark- or pale- 

 greyish or lead-coloured ; the areolae more or less tumid, crowded 

 or dispersed (K + yellowish, CaCl — , medulla I + reddish) ; 

 hypothallus thin, black. Apothecia small, subinnate, at length 

 partly prominent, at first depressed, then plane, at times convex, 

 black, the margin thin, entire or obsolete ; hypothecium thin, 

 nearly colourless or brownish ; paraphyses discrete, bluish-black 

 at the apices; spores ellipsoid, 0,010-17 mm. long, 0,006-8 mm. 

 thick ; hymenial gelatine bluish then sordid, the asci tawny- 

 wine-red, with iodine. — L. tenebrosa Flot. ex Nyl. in Act. Soc. 

 Linn. Bord. ser 3, i. p. 373 (1856); Mudd Man. p. 204; Cromb. 

 Lich. Brit. p. 85; Leight. Lich. Fl. p. 281; ed. 3, p. 283. 

 Verrucaria griseoatra Hoffm. Deutschl. Fl. p. 182 (1795). 



Exsicc. Leight. n. 188 (in some sets) ; Cromb. n. 185. 



From its appearance this has been placed in Lecanora, near 

 L. cinerea. The thallus is occasionally partly limited by the hypo- 

 thallus, which is in young plants radiating. In our specimens the 

 apothecia are usually numerous and not unfrequently abortive. The 

 asci are cylindrical-clavate, somewhat lax, and with the paraphyses 

 separate readily from the hypothecium. The spermogones, rarely 

 present, have the spermatia short, straight, bacillar, 0,006-9 mm, long, 

 about 0,001 mm. thick (fide Th. M. Fries Lich. Scand. p. 541). 



Hab. On rocks in maritime and mountainous districts. — Disfr. 

 Local, though plentiful where it occurs in the Channel Islands, 

 N. England and Wales, among the Grampians, Scotland ; apparently 

 rare in S.E. Ireland. — B. M. Noirmont, Jersey ; Sark ; Malvern 

 Hills, Worcestershire ; Cader Idris, Barmouth, and Dolgelly, Merioneth ; 

 Cwm Idwall, Nant Francon, Carnarvonshire ; Windermere, Westmore- 

 land ; Cleveland, Yorkshire ; Achosragan Hill, Appin, Argyll ; Crian- 

 larich, Ben Lawers, and Ben-y-gloe, Perthshire ; Portlethen, Kincar- 

 dineshire ; Glen Callater and Morrone, Braemar, Aberdeenshire ; 

 Ben Nevis, Invernessshire ; near Cork. 



161. L. fuscocinerea Nyl. in Bot. Not. 1852, p. 177.— Thallus 

 effuse rimose-areolate, unequal, greyish- or blackish-brown, the 

 areolae often warted and tuberculate (K — , CaCl — , medulla 

 K 4- yellow) ; hypothallus blackish. Apothecia moderate, ap- 

 pressed or adnate, somewhat plane with thin prominent margin, 

 usually thinly gyrose, variously flexuose or angulose, black ; 

 hypothecium brownish-black ; paraphyses slender, concrete, dark- 

 brown at the clavate apices ; spores subglobose - ellipsoid, 

 0,010-14 mm. long, 0,007-9 mm. thick; hymenial gelatine pale- 

 bluish then wine-red with iodine. — Leight. Lich. Fl. ed. 3, p. 285. 



Subsequently referred by Nylander (Lich. Scand. p. 231) to 

 L, tenebrosa Flot., which it resembles when the thallus is darker 



