222 LTCHENACEI. [PLATTSMA. 



Hob. On old pales and firs, very rarely on boulders, in hilly and 

 mountainous districts. Distr. General and not uncommon in S., 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 Auglesea; 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 ffrt.), Braemar, Aberdeenshire ; Glen Nevis, Loch Ennich, and 

 Rothienmrchus Woods, Inverness-shire ; Lairg, Sutherlandshire. 



5. P. diffusnm 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 rhizinse ; laciniae 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 

 diffuses Web. Spic. Fl. Gott. (1778) p. 250 ; Dicks. Crypt, fasc. iii. 

 17, t. 9. f. 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. 130. 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. Exs. : Leight. B. 47; Mudd, 

 n. 71 ; Dicks. Hort. Sic. n. 23. 



Not unlike Parmeliopsis aleurites Nyl., but the spennogones place it in 

 this genus. The thallus is often densely isidiiferous almost throughout, 

 only the apices of the laciniae 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 wooded lowland 

 and upland districts. Distr. Somewhat local in England, N. Wa'es, and 

 the Highlands of Scotland ; rare in S. 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, Merionethshire ; Baysdale, 

 Cleveland, Yorkshire. Barcaldine, Lome, Argyleshire ; Inverarnan and 

 Crianlarich, Perthshire; Glee Dee, Braemar, Aberdeenshire ; Rothienmr- 

 chus, Inverness-shire. Askew Wood and Dunkerron, co. Kerry. 



6. P. Fahhmense Nyl. Syn. i. (1860) p. 309. Thallus suborbi- 

 cular, appresso-imbricate, smooth, laciniate, spadiceo-browuish or 

 brownish-black, beneath blackish, with a few rhizinaa at the cir- 

 cumference ; laciniae narrow, multifld, sinuate, subcanaliculate 



