354 LICHENACEI. [LECANORA. 



Hab. On rocks, boulders, and walls, sometimes on flints, tiled roofs, 

 rarely on oak pales, in maritime and upland districts. Distr. General, 

 though somewhat scarce where it occurs, in the Channel Islands and 

 England ; rarer in Scotland and Ireland. B. M. : Fliquet Bay, Island of 

 Jersey ; Vale Castle, Island of Guernsey ; Island of Sark. Thetford 

 Warren, Norfolk ; Yarmouth, Suffolk ; near London, Middlesex ; Shiere, 

 Surrey ; Penshurst, Kent ; near Hyde, Isle of Wight ; near Bovey Tracey, 

 S. Devon ; Penzance, Cornwall ; Malvern Hills, Worcestershire ; Bed- 

 fordshire ; Ross, Herefordshire ; Twycross, Leicestershire ; Bridge of 

 Ludlow, Haughmond Hill, Oswestry, and Caer Caradoc, Shropshire ; Bar- 

 mouth and Cader Idris, Merionethshire ; Llandyssil, Cardiganshire ; 

 Island of Anglesea ; Cliffrigg, Cleveland, Yorkshire ; near Eglestor.e, 

 Durham; Kendal and Brougham Castle, Westmoreland; Wauk and 

 Gunnerton Crags, Northumberland. New Galloway, Kirkcudbright- 

 shire ; Arthur's Seat and Dalmahoy Hill, Edinburgh ; Kyles of Bute, 

 Arran ; Burntisland, Fifeshire ; near Connel Ferry, Argyleshire ; Ben 

 Lawers, Perthshire ; Forfarshire ; Castleton of Braemar, Aberdeenshire. 

 Kilcully, near Cork ; near Belfast, co. Antrim. 



Var. /3. diffracta Nyl. Lich. Scand. (1861) p. 133. Thallus 

 almost entirely areolato-diffract ; areolae angular, usually blackish 

 at the margins. Apotbecia dark-reddish. Cromb. Grevillea, xviii. 



L44. Squamaria saxicola var. diffracta Cromb. Lich. Brit. p. 45 ; 

 ight. Lich. Fl. p. 1 73, ed. 3, p. 159. Lichen diffrachis Ach. Prodr. 

 (1798) p. 63. Squamaria saxicola var. areolata Leight. Mudd, 

 Man. p. 129. Brit. Exs. : Leight. n. 81 ; Mudd, n. 93. 



In this variety the radii, which are constantly pi me, are visible only at 

 the immediate circumference, the rest of the thallus being entirely areo- 

 late. The apothecia in our specimens are but sparingly present, with 

 the thalline margin subcrenate and at length nearly obliterated. 



Hab. On rocks in upland and subalpine situations. Distr. Local and 

 scarce in S.W., W., and N. England, and among the S. andN. Grampians, 

 Scotland. B. M. : St. Minver, Cornwall ; Haughmond Hill, Shropshire ; 

 near Ayton, Cleveland, Yorkshire. Ben Lawers, Perthshire ; Craig Guie, 

 Braeruar, Aberdeenshire. 



Yar. y . versicolor Fr. fil. Lich. Scand. (1871) p. 226. Thallus 

 whitish-yellow, more or less suffused with white. Apothecia with 

 the thalline margin often white-pulverulent. Cromb. Grevillea, 

 xviii. p. 44. Squamaria saxicola var. versicolor Leight. Lich. Fl. 

 p. 174, ed. 3, p. 159. Lichen versicolor Pers. in Ust. Ann. vii. 

 (1794) p. 24. 



Differs in the colour of the usually smaller thallus, and in the character 

 of the thalline margin of the somewhat crowded apothecia. Rarely it 

 occurs with only the peripheral radii visible and scattered over the sub- 

 stratum (form distans Cromb.), but this is quite accidental. 



Hab. On calcareous and schistose rocks in maritime and hillv tracts. 

 Distr. Rather sparingly in W. England, Wales, the S.W. Highlands 

 and the Central Grampians, Scotland. B. M.: Chance's Pitch, Malvern, 

 Worcestershire ; St. David's, Pembrokeshire ; Barmouth, Merioneth. 

 Island of Lismore, Argyleshire ; Craig Tulloch, Blair Athole, Perthshire. 



