OF GREAT BRITAIN. 149 



forma denMctdatcv, r (Ach.) margins of thallus coarsely fringed and 

 toothed ; metlula' R — C — . 

 On alpine rooks. 



Syn:— Ach. Meth. 107. (18030 Leight. Br. TXmbil. 21. Mudd Man. 119. ' 

 iSta:— I). Bot. 52». Jtwo lower fig.) Dill. t. 29. f. 116. B. 

 Exs :— Schser. 144. 

 Scotland : — Loch Phadrick ! Ben-na-Bourd ! Mr. Gardiner. CtSva ! Mr. 



Ireland : — Galtymore ! co. Tipperary. Mr. Carroll. . . 



Wales : — Arran Mowddwy! Mr. Borrer. 



In all respects similar, except that. the marginal fibres are coarser and larger, 

 and more evidently a prolongation of the thallus. 



forma, detjludata, (T. <fc B.) margins of thallus almost naked; 

 medulla K — C — . 

 On alpine rocks. 



• Stn :— Turn, and Borr. Lich. Brit. 219. (1813.) Leight. Br. Umbfl. 21. Mudd 

 Man. 119. 

 Fig :— Hff m. PI. L. t. 44. f. 7. 



Exs : — Schaer. 145, 



England :^Ealcon Glints I Westmoreland Mountains ! Mr. Borrer. 



Scotland :— Highlands. Messrs. Turner & Borrer. 



Wales : — Summit of Glyders ! Mr. Borrer. 



forma ezasperata, (T. & B.) thallus polyphyllqus, ragged, upper 

 surface rugose, margins undulate and crisped , medulla K-^- C — . 

 On alpine rocks. 



Stn:— Turn. & Borr. Lich. Brit. 219. (1813.) Leight. Br. Umbil. 22. Mudd 

 Man. 119. 



England :— Durham. Mr. Sobson. 



Scotland : — Clova ! Mr. G. Lawson. 



Remarkably curled and undulated, and divided into numerous small irregular 

 laeinise ; upper surface remarkably rough. 



Series V. PLACODEI. 



Thallus crustaceous, squamose, radiate, granulose, powdery or 

 evanescent. Apotheoia lecanorine or lecideine, or biatorine or 

 lirelliform. 



Tribe XIV. LECANOREl. 



Thallus various. Apothecia lecanorine or sub-lecanorine or 

 pseudo-biatorme. 



Sub-tribe I. PSOROMEI. 



Thallus variously squamulose, in texture conspicuously cellulose, 

 gonidia distinct large. Apothecia lecanorine. Spores 8, colourless, 

 large and simple. Paraphyses distinct. Spermogonia with, arthro- 

 sterigmata. 



I. PSOROMA, Fr. pr. p. Nyl. 



Thallus variously squamulose, cellulose, gonidia distinct, large. 

 Apothecia lecanorine, margin crenate. Spores 8, colourless, large; 

 ellipsoid, simple. Paraphyses distinct. Sterigmata pluri-articulate. 



1. P.,hypnorum, (Vahl.) flavido-fuscescent or brownish-yellow, 

 squamuloso-granulate, squamulse crenate or sub-granulose ; apo^ 



