222 LICHENACET. *  [PLATYSMA. 
Hab, On old pales and firs, very rarely on boulders, in hilly and 
mountainous districts Distr. General and not uncommon in 8., W., 
and N. England and the Highlands of Scotland; not seen from Ireland. 
—B.M: Between Yarmouth and Caistor, Suffolk; near St. Leonards 
and Ifield, Sussex ; Hay Tor, Devon; Bardon Hill and Gopsall, Leicester- 
shire; Oteley Park, Ellesmere, Shropshire; Cwm Bychan, Merioneth- 
shire ; Island of Anglesea; Ingleby Park, Cleveland, Yorkshire ; Teesdale, 
Durham; Ashgill, Cumberland. New Galloway, Kirkcudbrightshire ; 
Glen Falloch, Killin, Ben Lawers, Glen Lyon, and Falls of Bruar, Perth- 
shire ; Deerhill Wood and Kinnoul Wood, Forfarshire ; Morrone and Linn 
of Quoich (frt.), Braemar, Aberdeenshire; Glen Nevis, Loch Ennich, and 
Rothiemurchus Woods, Inverness-shire; Lairg, Sutherlandshire. 
5. P. diffusum Nyl. Flora, 1872, p. 247.—Thallus orbicular, ap- 
pressed, closely adherent, isidioso-rugose in the centre, naked and 
sinuato-lobed at the circumference, greyish- or brownish-white, 
beneath pale brown, with a few long rhizinw; lacinie narrow, ap- 
planate, multifid, rounded and crenate at the apices (K + deep yellow, 
CaCl_). Apothecia small, subopaque, reddish-brown, the margin 
crenulate and sorediate; spores ellipsoid, 0,006—-9 mm. long, 0,005 
—6 mm. thick.—Cromb. Journ. Bot. 1872, p. 234; Leight. Lich. Fl. 
ed. 3, p. 95.—Parmelia diffusa Gray, Nat. Arr. i. p. 442. Lichen 
diffusus Web. Spic. Fl. Gott. (1778) p. 250; Dicks. Crypt. fase. iii. 
17, t. 9. £6; With. Arr. ed. 3, iv. p. 32. Parmeliopsis aleurites 
(Ach.), Cromb. Lich. Brit. p.37. Parmelia aleurites Hook. Fl. Scot. 
ii, p. 54; Sm. Eng. Fl. v. p. 203; Mudd, Man. p. 98; Leight. Lich. 
Fl. p. 180. Lichen aleurites Eng. Bot, t. 858.—To this is referable 
Parmelia horrescens Tayl. in Mack. Fl. Hib. ii. p. 144 pro parte (cfr. 
Cromb. Grevillea, vii. p. 98).—Brit. Hws.: Leight. n. 47; Mudd, 
n. 71; Dicks. Hort. Sic. n. 23. 
Not unlike Parmeliopsis aleurites Nyl., but the spermogones place it in 
this genus. The thallus is often densely isidiiferous alwost throughout, 
only the apices of the laciniz being naked. It usually occurs sterile ; 
when present the apothecia are elevated and numerous. The spermogones 
are large, black, marginal and tubercular, with spermatia 0,004 mm. long, 
about 0,001 mm. thick. 
Hab. On old pales, rarely on stumps of felled trees in wonded lowland 
and upland districts. Distr. Somewhat local in England, N. Wa'es, and 
the Highlands of Scotland; rare in 8. W. Ireland—B. M.: Henham, 
Suffolk; Penshurst, Kent; Wakehurst, Sussex; Croft Castle and near 
Hereford, Herefordshire; near Windsor, Berkshire; Stoke Park and 
Sotterly Park, Buckinghamshire ; Gopsall, Leicestershire ; near Oswestry 
and Ellesmere, Shropshire; Cwm Bychan, Mericnethshire ; Baysdale, 
Cleveland, Yorkshire. Barealdine, Lorne, Argyleshire ; Inverarnan and 
Crianlarich, Perthshire ; Glee Dee, Braemar, Aberdeenshire ; Rothiemur- 
chus, Inverness-shire. Askew Wood and Dunkerron, co. Kerry. 
6. P. Fahlunense Nyl. Syn. i. (1860) p. 309.—Thallus suborbi- 
cular, appresso-imbricate, smooth, laciniate, spadiceo-brownish or 
pbrownish-black, beneath blackish, with a few rhizine at the cir- 
cumference ; lacinie narrow, multifid, sinuate, subcanaliculate 
