278 LICHENACEI. [PELTIDEA. 



1. P. aphthosa Ach. Lich. L'niv. (lJ<10) p. 516. — Thalliis broadly 

 membranaceous, thin or modei'ate, smooth, somewhat shining, bearing 

 cephalodia, bright grass-green when moist, glaucous-green or lurid- 

 glaucous when dry : beneath either reticulately blackish-nervose or 

 almost continuously brownish-black, with broad whitish margin ; the 

 rhizinge long, Idackish. Apothecia rotundate, moderate or large, 

 ascendinjr, reddish-brown, the margin inflesed and lacerate ; spores 

 8nae, fusiform, 3-7-septate, colourless or pale-brown, 0,060-92 mm. 

 long, 0,005-6 mm. thick.— Gray, Xat. Arr. i. p. 428 ; Hook. Fl. Scot, 

 ii. p. 60 ; Sm. Eng. Fl. v. p. 215 ; Tayl. in Mack. Fl. Hib. ii. p. 153 ; 

 Cromb. Lich. Brit. p. 2S. — Peltigem aphiliosa Mudd, Man. p. 81 ; 

 Leight. Lich. Fl. p. 107, ed. 3, p. 101, Lichm apJithosus Linn. Fl. 

 Suae. (1755) p. 1098 ; Lightf. Fl. Scot. ii. p. 847: Huds. Fl. Angl. 

 ed. 2, p. 547; With. Arr. ed. 3, iv. p. 70; Eng. Bot. t. 1119. 

 Lichenoides digitatum iMe-virens, verrucis nigris notatum Dill. Muse. 

 199, t. 27. f. 108. — Some of the above ijiclude no doubt also the 

 following variety. — Brit. Exs. : Leight. n. 321 ; Cromb. n. 147. 



The epigenous cephalodia distinguish this from other species of the 

 tribe. They are patelliform or verrucoso-unequal, pale, either superficial 

 or slightly impressed, usually numerous and sprinkled over the whole 

 upper surface of the thallus. The underside is sometimes continuously 

 blackish, with conHuent nerves (form verrucosa "Web.) ; but this seems 

 to be an accidental state resulting from the nature of the substratum. In 

 this country it is rarely seen in fruit ; the old apothecia become rather 

 large. 



Hub. Among mosses on rocks and boulders, as also on turf walls in 

 moist shady upland districts. — Distr. Local and scarce in "W. and X. Eng- 

 land and S. Scotland ; more plentiful in the Grampians, Scotland, where 

 it fruits more freely ; rare in N. Ireland. — B. M. , Stouts" Wood, Glou- 

 cestershire : near Buxton. Derbyshire; Craigforda, Herefordshire ; Llyn 

 Bodlyn. Meiionethshire ; Llauberris, Carnarvonshire ; Teesdale, Durham ; 

 near Kendnl, Westmoreland ; Walla Crag, Cumberland ; The Cheviots, 

 Xorthumberlaud. Falls of the Clyde, Lanarkshire ; near Inverary and 

 Barcaldine, Argyleshire ; Glen Lochay, Killin, Blair Athole, Den of 

 Rechip, Perthshire ; Sidlaw Hills, Forfarshire ; Craig Cluny, Invercauld, 

 and Craig Coinnoch, Braeniar, Aberdeenshire ; Loch Linnhe, Lochaber, 

 Inverness-shire. Near Belfast, co. Antrim ; Counemara, co. Galway. 



Var. ft. leucopMebia Xot. Siillsk. F. et Fl. Fenn. Forh. n. s. v. 

 (1866) p. 117. — Thallus less dilated, paler, more opaque; beneath 

 entirely whitish ; the nerves distinct, whitish or pale. Apothecia 

 rare : spores 3-septate, 0,052-0,066 mm. long. 0,004-6 mm. thick. 

 — PeJtiqera ajihthosa, var. leucojphlehia Xvl. Syn. i, (1860) p. 323. 

 —Brit Exs. : Mudd, n. 58. 



Differs in the usually smaller thallus, the colour of its upper and under 

 surfaces, and in the pauci-septate spores. Nylander (Syn. /. c.) observes 

 that it had somewhat the habit of Feltigera riffescctis (this, hoAvever, is 

 less marked in our British specimens), but with the pecidiar cephalodia 

 of this species. In this country it is always sterile. 



Hr/h. Among mosses on shady rocks in upland districts. — Distr. Local 

 and rare in S.W. and X. England, in S. Scotland, and the S. and W. 



