IBOIDBA] LBOIDBACEiE 63 



CaCl — ). Apothecia small, somewhat prominent, thinlj mar- 

 gined, umbonate or at length subgyrose in the centre, black, 

 <3oncolorous within; epithecium (in thin section) brown; hypo- 

 thecium dark-brown; paraphyses moderate, coherent; spores 

 ellipsoid, 0,010-12 mm. long, 0,006-8 mm. thick; hymenial 

 gelatine deep-blue with iodine. — Cromb. in Grevillea iii. p. 23 ; 

 Leight. Lich. Fl. ed. 3, p. 287. 



In the specimens seen the apothecia are rather scattered and not 

 very numerous. 



Hah. — On schistose rooks in upland tracts of mountainous regions. 

 —Distr. Sparingly in N. Wales, the S. Orampians, Scotland, and 

 N.W. Ireland. — B. M. Cader Idria, Merioneth ; Trefriw, Denbighshire ; 

 Stronachlan, Ben Lawers, KUlin, and Looh-na-gat, Perthshire ; Dough- 

 ruagh Mt., Gralway. 



105. L. tabidula Nyl. in Flora Ixii. p. 357 (1879).— 

 Thallus effuse, scattered, thin, or very thin, unequal, blackish 

 (K — , CaCl — ). Apothecia minute, plane, slightly margined, 

 often aggregate, black, concolorous within ; paraphyses not very 

 well discrete ; epithecium sordid-bluish-black ; hypothecium and 

 perithecium dark-brown (or reddish-brown in thin section) ; 

 spores ellipsoid, 0,011-16 mm. long, 0,006-7 mm. thick; hy- 

 menial gelatine bluish then tawny-wine-coloured with iodine. — 

 Cromb. in Grevillea viii. p. 112. 



The thallus, but little visible, appears only in the immediate 

 vicinity of the fructification which generally occurs in small, scattered 

 groups. Very near L. depcureula, but differs in the thallus, the para- 

 physes, and the reaction of the hymenial gelatine. Spermogones are 

 here and there present with slightly arcuate spermatia, 0,012-14 mm. 

 long, 0,0005 mm. thick, though, as Nylander conjectures, these may 

 be foreign, faint traces of another thallus being occasionally visible in 

 the chinks of the substratum. 



Hah. On quartzose stones in an alpiae situation. — B. M. Summit 

 of Ben-y-gloe, Blair Athole, Perthshire (the only locality). 



106. L. jurana Schser. Enum. p. 123 (1850).— Thallus effuse, 

 thin, continuous, subrimulose or scattered, whitish, often almost 

 obsolete (K— , CaCl — ). Apothecia adnate, somewhat large and 

 scattered, at first concave then plane with thickish prominent 

 flexuose margin, often irregular and 2-3 connate, black, naked, 

 concolorous within ; paraphyses subcoherent ; hypothecium and 

 epithecium blackish; spores ellipsoid, 0,016-18 mm. long, 

 010-11 mm. thick ; hymenial gelatine deep-blue with iodine. — 

 Leight. in Ann. Mag. Nat. Hist. ser. 4, iv. p. 199 (1869); Lich. 

 Fl. p. 299 ; ed. 3, p. 310. 



In the British specimens the thallus is either rather scattered 

 (form dispersa Arnold in Flora li. p. 35 (1868)), or more commonly 

 scarcely visible. The apothecia are rather variable, being frequently, 

 as Sohsrer says, minute and several aggregate with a common exciple. 



