320 THE LICHEN-FLORA 



On subputrescent wood and stumps, probably not uncommon. 



Syn :— Aoh. L. Univ. p. 177. (1810.) 

 Fig :— Mass. Ric. 165. Hepp Sporen t. 17. f. 150. 



Exs :— M. & N. 1328. Rabh. 729. Anzi It. S. 296. 300. 301. Hepp 150. Schajr. 

 198. Richardson 144. 149. 

 Geog. Disteib : — Switzerland, Germany, N. America. 

 Bot. Pbov:— 10...31. 



England :— Earndale ! Yorkshire. Mr. Mudd. (1856.) 

 Channel Islands : — St. Clement's Bay ! Jersey. Mr. Larbalestier. 



B. Saxicolar forms. 



forma areolata, Leight. cinerascent, thin, effuse, minutely rimoso- 

 areolate, areolae plane ; apothecia black, numerous, crowded, adnato- 

 sessile, plane ; margin slightly prominent, thickish and paler, 

 eventually obliterated ; excipulum lateral, nigro-fuscous, short ; 

 hypothecium central nigro-fuscous ; paraphyses distinct, cohserent, 

 apices very large, nigro-fuscous or nigricant ; spores 8, fuscous, 

 oblong, 1-septate, small ; gelatina hymenea I violet. 



Syn :— Leighton in Grevillea 5. p. 81. (1876.) 



Exs :— Schser. 447. 



Geog. Distbtb :— Switzerland. 



Bot. Pbov :— 5, 6.. .26. 



England : — Caer Caradoc ! Shropshire. (1856.) 



Ibeland : — Ballinahinch ! base of Dougbruagh (east side) ! Mr. Larbalestier. 



Wales : — Goodwick Bay ! near Fishguard, Pembrokeshire. 



Spores .012— .014 mm. long, .006— .007 mm. broad. The thallus has no re- 

 action with K or C, but when C is applied after being wet with K, a singular 

 whitish effervescence ensues. 



forma leprosa, Leight. albido-cinerascent, areolae dissolved into a 

 Uprose, pulverulent, effuse condition. 



Syn :— Leighton in Grevillea 5. p. 10. C1876.) 



Exs: — Fellm. 197. Zw. 127. Leight. 181. Mudd 189. 



Geog. Distbtb : — E. Lapland, Germany. 



Bot. Pbov :— 5, 6 ..10...26. 



England : — Cliffrigg ! Yorkshire. Mr. Mudd. Haughmond TTill ! Shropshire. 



Ibeland : — Kylemore Mountains ! Mr. Larbakstier. 



Wales : — Goodwick Bay ! Newport Road ! near Fishguard, Pembrokeshire. 



forma ecrustacea, Leight. thallus nearly or quite evanescent and 

 obliterated, leaving the numerous minute apothecia naked and 

 prominent. 



Syn :— Leighton in Grevillea 5. p. 10. (1876.) 



Bot. Pbov:— 2.. .5, 6...10...20...26. 



England : — Ashington Common ! Sussex. Mr. Sorrer. Cliffrigg ! Yorkshire. 

 Mr. Mudd. Haughmond Hill ! Sharpstones Hill ! Lyth Hill ! Longmynd ! 

 Shropshire. 



Ibeland :— Near Kilcully, Cork I Mr. Carroll, near Tillage of Glencorbot! 

 Doughruagh Mountain ! Galway. Mr. Lwrbaltstier. 



Wales : — Goodwick Bay ! St. David's ! Pembrokeshire. Chapel Lawn ! near 

 Gaer Ditches, Radnorshire, 



Intermediate states were often observable connecting the above forms. 

 Externally f. ecrustacea resembles L. dispansa, Nyl., but the different spores 

 prevent confusion. According to specimens received years ago from Mr. 

 Borrer, as occurring with his true L. prominula, on flints on the Sussex Downs, 

 this form would appear to be the lichen mentioned by him in E. Bot. SuppL t. 

 2687, as probably "true L. lygasa, Ach." It should be remembered that Mr. 

 Borrer determined his lichens by external characters alone, the confirmatory 

 character of the spores being at that time scarcely thought of. 



