PERTTTSAEIA.] LECANO-LECIDKET. 501 



The thallus spreads extensively and is occasionally of considerable 

 thickness. It is usually more or less covered with short, simple, con- 

 colorous papillae which are at length fractured into rugose areolse. 

 When fertile the verrucse are generally aggregate, becoming irregularly 

 lacerate. It is, however, more frequently sterile, and is then at times 

 the host of the parasitic Spiloma sphcerale Ach., which occurs also on the 

 form. 



Hob. On rocks, boulders, and walls in maritime and mountainous 

 regions. Distr. Apparently general and common in Great Britain and 

 Ireland ; rare in the Channel Islands. B. M. : Island of Sark. Dartmoor 

 Tors, Devonshire ; St. Austell, Cornwall ; Malvern Hills, Worcestershire ; 

 Barmouth, Aberdovey, and Cwm Bychan, Merionethshire ; Island of 

 Anglesea ; Oswestry and Caer Caradoc, Shropshire ; Kildale Moor, 

 Cleveland, Yorkshire ; Teesdale, Durham. Ben Cruachan, Argyleshire ; 

 The Trossachs, Crianlarich, Ben Lawers, and Craig Calliach, Perthshire ; 

 Sidlaw Hills and Clova, Forfarshire ; Glen Callater, Braemar, Aberdeen- 

 shire. Dunkerron and Finnehy River, co. Kerry; Dawros River, 

 Connernara, co. Galway. 



Form corallina Cromb. Grevillea, xii. (1883) p. 59. Thallus 

 thick, densely papillose ; the papillae elongate, thin, simple and 

 branched. P. syncarpa y. corallinum Mudd, Man. p. 273. Isidium 

 coralUnum Gray, Nat. Arr. i. p. 412 : Turn. & Borr. Lich. Br. 

 p. 100; Hook. Fl. Scot. ii. p. 66 ; Sm. Eng. Fl. v. p. 231. Lichen 

 corallinus Linn. Mant. (1767) p. 131 ; Huds. Fl. Angl. ed. 2, p. 526 ; 

 Lightf. Fl. Scot. ii. p. 808 ; With. Arr. ed. 3, iv. p. 16 pro parte ; 

 Eug. Bot. t. 1541. 



Differs from the type in the character of the isidioid papillae. It is, 

 however, connected with it by intermediate states, so that perhaps it is 

 to be regarded only as a luxuriant condition. It is never seen fertile. 



Hob. On rocks in maritime and upland situations. Distr. Seen in 

 a typical state only from a few localities in Great Britain and Ireland. 

 B. M. : near Pont-ned-vechan, Brecknockshire ; Barmouth, Merio- 

 nethshire ; Island of Anglesea ; Ayton Moor, Cleveland, Yorkshire ; 

 Eglestone, Durham ; Alston, Cumberland. Ben-y-gloe, Perthshire ; 

 Baldovan Woods, Forfarshire. The Dargle River, co. Wicklow. 



15. P. ceuthocarpa Turn. & Borr. Lich. Br. (1839) p. 200; 

 Nyl. Mem. Soc. Cherb. t. T. p. 116. Thallus determinate, thickish, 

 areolato-diffract, cream-coloured; the areolae convex, undulato- 

 rugose (K-j- yellow, then deep orange-red). Apothecia few, in sub- 

 globose, smooth, conglomerate verrucas ; the ostioles minute, 

 punctiform, blackish; spores 2nse, 0,150-170 mm. long, 0,057- 

 60 mm. thick. Sm. Eng. Fl. v. p. 160; Mudd, Man. p. 271; 

 Cromb. Lich. Brit. p. 58 ; Leight. Angio. Lich. p. 28, t. 9. f. 4 ; 

 Lich. Fl. p. 237, ed. 3, p. 228. Porina ceuthocarpa Tayl. in 

 Mack. Fl. Hib. ii. p. 102. Lichen ceuthocarpusSm. Eng. Bot. xxxiii. 

 (1812) t. 2372. Brit. Exs. : Leight. n. 284. 



Apparently an endemic species well distinguished by the characters 

 given. The areolaa are at times plane, especially towards the circum- 

 ference, where the plant is limited by a dark-olive hypothalline margin. 



