234 LICHENACEI. [PARMELIA. 



glaucous-white, beneath black, glabrous, rugulose, the lobes eroso- 

 crenate and ciliate at the margins (K|Xw~ yellOW> CaC1 D- A P- 

 thecia moderate or large, scattered, elevated, urceolato-subpedieellate, 

 badio-reddish, the margin frequently eroso-crenate and sometimes 

 ciliate ; spores as in the preceding. Cromb. Grevillea, xv. p. 74. 

 Parmelia perlata ft. ciliata Mudd, Man. p. 92 pro parte ; Cromb. 

 Lich. Brit. p. 32 ; Leight. Lich. Fl. p. 129, ed. 3, p. 120. Lobaria 

 perlata var. ciliata DC. Fl. Fr. ii. (1805) p. 403. Parmelia pro- 

 bosddea Tayl. in Mack. Fl. Hib. ii. p. 143. Parmelia perforata 

 Sm. Eng. Fl. v. p. 200 pro parte. Lichen perforatus Eng. Bot. 

 t. 2423 pro parte. As Nylander observes (Flora, 1809, p. 91), this 

 should perhaps be referred to P. crinita Ach. Brit. Exs. : Larb. 

 Caesar, n. 17 ; Lich. Hb. n. 86 ; Leight. n. 112 ; Cromb. n. 30. 



Differs from the type in being frequently more or less coralloideo- 

 isidiiferous (form evcrescens Am.) and in having the lobes, which are 

 occasionally dissected at the margins (form dissectula Nyl. in Leight. Br. 

 Fl. iii. p. 1:20), fringed with elongated cilia, which are sometimes shorter 

 or almost wanting. These differences, and the character of the margins 

 of the apothecia, entitle it to rank at least as a subspecies, if not as 

 a distinct species. In this country, as in most other parts of Europe, the 

 apothecia are rare. They are usually scattered, though sometimes two or 

 three are congregate and smaller. 



Sab. On the trunks of old trees, as also on rocks and boulders in shady 

 places in maritime and upland districts. Distr. General in S. and 

 W. England and N. Wales ; rarer in the W. Highlands of Scotland, 

 W. Ireland, and the Channel Islands. B. M. : E. coast of Jersey; Island 

 of Guernsey. High Rocks, Tunbridge Wells, Kent ; St. Leonard's Forest, 

 Sussex ; Isle of Wight ; Lustleigh Cleeve, Hay Tor, Lydford, and Bolt 

 Head, Devonshire ; near Penzance and Helminton, Cornwall ; St. Mary's, 

 Scilly Islands ; Malvern, Worcestershire ; Dolgelly, Nannau, and Bar- 

 mouth, Merionethshire ; River Elwy, Carnarvonshire ; Keswick and 

 Eskdale, Cumberland ; near Kendal, Westmoreland. New Galloway, 

 Kirkcudbrightshire ; near Helensburgh, Dumbartonshire ; Barcaldiue, 

 Argyleshire ; shores of Loch Tay, Perthshire ; Lochaber, Inverness- 

 shire ; Applecross, Ross-shire. Dunkerron Mt.s., Killarney, and Dinis, 

 co. Kerry ; Connemara, co. Galway. 



2. P. olivetorum Nyl. Not. Sallsk. pro F. etFl. Fenn. Forh. n. s. 

 v. (1866) p. 180. Thallus expanded, roundly lobed, smooth, 

 greyish-green ; beneath blackish, very sparingly and shortly rhi- 

 ziuose, lobes elevated, crisp, incurved, thickened and white-sorediate 

 at the margins (K+ yellow , CaCl"^). Apothecia moderate, reddish- 

 brown, the thalline margin entire ; spores 0,014-18 mm. long, 

 ,0,007-12 mm. thick. Leight. Lich. Fl. p. 130, ed. 3, p. 121. 

 ' Parmelia perlata ft. olivetorum Ach. Lich. Univ. (1810) p. 458. 



From the sorediate states of P. perhita this is at once distinguished by 

 the different reaction of the medulla with CaCl. The soredia are minute, 

 confined to and bordering the margins of the lobes. When growing, ai;d 

 in wet weather, it is of a greenish colour, resulting from the cortical layer 

 being subhyaline (Nylander, Pyr. Or. p. 16). Neither apothecia nor 

 spermogones are present in our British specimens. 



