PHYSCIA.] I'HYSCIEI. 305 



and Rough ton, Cornwall ; Barmouth, Cwm Bychan, and Llyn Bodlyn, 

 Merionethshire. Barcaldine and Ballachulish, Argyleshire ; Glen Fal- 

 loch, Perthshire. Dunkerron and Killarney, co. Kerry. 



Yar. ft. hypoleuca Nyl. Syn. i. (1860) p. 417. Thallus usually 

 firmer, with the laciniae more closely imbricate ; beneath, white, 

 here and there hispid with black rhizinse, the marginal cilia black. 

 Apothecia with the margin of the receptacle crenate or radiato- 

 fimbriate. Cromb. Grevillea, xv. p. 78. Parmelia speciosa var. 

 liypolmca Ach. Syn. (1814) p. 211. Parmelia speciosa Tayl. I. c. 

 pro parte. Lichen speciosus Eng. Bot. t. 1979 (lower figs.). 



An exotic variety which finds its way to S.W. Ireland. The thallus 

 in our British specimens is more sorediate than in the type ; and the 

 margin of the apothecia, which are somewhat large and crowded, is 

 thickish, crenate, and densely pulverulent. 



Hob. On rocks in shady upland situations. Distr. Extremely local 

 and rare in S.W. Ireland. B. M. : Dunkerron, co. Kerry. 



10. P. pulverulenta Nyl. Act. Soc. Linn. Bord. se'r. 3, i. (1856) 

 p. 308. Thallus sub orbicular, somewhat firm, substellato-appressed, 

 opaque, multifido-laciniate, pale-greyish or greyish-brown, more or 

 less white-pruinose ; beneath rough with dense blackish fibrillose 

 rhizinae ; lacinise plane, obtuse and crenato-incised at the apices 

 (K~, CaCl~). Apothecia sessile, large, concave or plane, brownish- 

 black, caesio-pruinose or naked, the margin thick, indexed, entire, 

 pruinose : spores oblong, 0,020-36 mm. long, 0,012-20 mm. thick. 

 Cromb. Lich. Brit. p. 38 ; Leight. Lich. PI. p. 146, ed. 3, p. 135. 

 Borrera pulverulenta Mudd, Man. p. 110. Parmelia pulverulenta 

 Gray, Nat. Arr. i. p. 443 ; Hook. PI. Scot, ii. p. 55 ; Sm. Eng. PL 

 v. p. 201 ? Tayl. in Mack. Fl. Bib. ii. p. 141. Lichen pulverulentus 

 Schreb. Spic. (1771) p. 128. Lichen stellaris ft. Huds. PI. Angl. 

 p. 448 ; With. Arr. ed. 3, iv. p. 31. Lichenoides glaucum orbiculare, 

 seymentis latiitsculis, scutettis nigris Dill. Muse. 177, t. 24. f. 71 A 

 pro parte. Lichenoides arboreum, crusta foliosa virescenti, tenuiter et 

 eleganter dissecta, scutellis nigris Dill, in Ray Syn. ed. 3, p. 74, n. 73 

 pro parte. Brit. Exs. : Leight. n. 49 ; Mudd, n. 82; Larb. Lich. 

 Hb. n. 10; Bohl. n. 69. 



This may generally be recognized by the pruina, with which, when 

 growing and in a dry state, it is more or less covered. As noticed, how- 

 ever, by Acharius (Lich. Univ. p. 474), when wetted the pruina disappears 

 both in the thallus and apothecia, the former being then greenish and the 

 latter black ; but when again dried the pruina returns in both. The 

 colour in a dry state varies in recent specimens from pale greyish to 

 greyish brown, and, as observed by Lightfoot (1. c. p. 825), specimens 

 after being kept for some years in paper (or in herbaria) turn to a russet- 

 grey (or cervine). In other respects the thallus and apothecia vary con- 

 siderably in character, giving rise to the subspecies, forms, and varieties 

 which follow. The apothecia are generally somewhat scattered, though 



