154 LECANO-LECIDEEI [bACIDIA 



i). B. effusa Arnold in Flora xli. p. 505 (1858).— Thallus 

 effuse, thin, crustaceous, scurfy, yellowish-green or whitish, 

 sometimes scarcely visible. Apothecia rather small, scattered 

 or sometimes several aggregate, at first plane with a thickish 

 margin, then convex and immarginate, pale-yellowish-flesh- 

 coloured, sometimes becoming reddish or brownish ; hypothecium 

 colourless ; paraphyses slender, subdiscrete, colourless, the epi- 

 thecium sometimes thinly brownish ; spores narrowly clavate, 

 straight or slightly curved, pluri-septate, usually about 0,045 

 mm. long, 0,001-2 mm. thick, sometimes shorter or sometimes 

 longer ; hymenial gelatine and asci blue with iodine. — Lichen 

 ejj'usus Sm. Engl. Bot. t. 1863, two upper figures (1808). Biatora 

 effusa var. ^ intermedia Hepp ex Stiz. in Acad. Cses. Leop. 

 Nov. Act. XXX. 3, p. 42, t. 2, f. 17 (1863). Lecidea effusa Leight. 

 Lich. Fl. p. 343 (1871) (excl. vars.) ; ed. 3, p. 370 (excl. vars.) ; 

 Cromb. in Grevillea xxii. p. 58 (inch var. intermedia, excl. vars. 

 arceutina and hypnsea). L. intermedia Leight. Lich. Fl. ed. 3, 

 p. 368 (1879). 



Exsicc. Larb. Lich. Hb. n. 233 ; Lich. Csesar. n. 74. 



Resembles jB. arceutina in the character of the thallus and the 

 long, narrow spores, but differs in the constantly lighter coloured 

 apothecia, which in some specimens become brownish. 



Hah. On trees. — Distr. Rare in the Channel Islands, England, 

 Wales and Ireland ; not recorded from Scotland. — B. M. New Forest, 

 Hants ; Stowell Park, Gloucestershire ; Penmaenmawr, Carnarvon- 

 shire ; Clififrigg, Cleveland, Yorkshire ; Westport, Mayo ; Lough 

 Feagli, Connemara, Galway. 



Form hemipolia A. L. Sm. — Thallus thin, whitish-grey, 

 smooth. Apothecia convex, semiglobose, partly pale-brownish, 

 partly livid ; epithecium yellowish ; otherwise as in the species. 

 — Lecidea arceutina f. hemipolia Nyl. in Flora lii. p. 413 (1869) 

 nomen. 



Characterized by the colour of the epithecium and of the con- 

 stantly convex apothecia. 



Hab. On the bark of trees in maritime districts in S. England. — 

 B. M. St. Lawrence, I. of Wight ; near Lymington, Hants. 



10. B. prasinoides Oliv. Exp. Syst. Lich. ii. p. 26 (1900).— 

 Thallus effuse, thin or very thin, subgranulate-leprose, greenish. 

 Apothecia minute, somewhat plane, obtusely or obsoletely 

 margined, pale-flesh-colour, within colourless; paraphyses slender, 

 colourless at the apices ; hypothecium colourless ; spores rod- 

 shaped or subfusiform, 1-3-septate, 0,012-21 mm. long, 0,0025-35 

 mm. thick ; hymenial gelatine and asci wine-red with iodine. — 

 Lecidea prasinoides Nyl. in Flora xlviii. p. 146 (1865) ; Carroll 

 in Journ. Bot. vi. p. 100 (1868); Cromb. Lich. Brit. p. 74; 

 Leight. Lich. Fl, p. 326 ; ed. 3, p. 345. 



Hab. On rocks. — B. M. Dinish, Killarney, Kerry. 



