LECAXORA.] LECANO-LECIDEEI. 421 



Leicestershire ; Malvern Hills, Worcestershire ; Pwllheli, Carnarvon- 

 shire; Island of Anglosea ; IIi.u<,'hmond Hill, Shropshire; Cliffri^rg', 

 Cleveland, and Kibbledale, Yorkshire ; near Miluthorpe, Westmoreland; 

 Swinhope, Xorthumbcrland ; Catterleen, Cumberland. New Galloway, 

 Kirkcudbrightshire; Kyles of Bute; Barraldine and Ben Cruachan, 

 Argyle.-hire : Killin, Perthshire ; near Dundee, Forfarshire ; Portlethen, 

 Kincardineshire ; Castleton of Braeniar, Aberdeenshire. Lambay Island 

 and Kin.-ale, co. Cork. 



Form 1. decussata Cromb, Grevillea, xviii. (1890) p. 68. — 

 ThaUus white or j?reyish-wbite, finely marked throughout with 

 black hypotlialline (?) lines. Apothecia as in the type, with con- 

 colorous thalliue margin. 



Looks at first sight as if almost referable to L. calcarea, but has the 

 reactions of this species. In our two British specimens the spermogones 

 are very abundant, giving the thallus a black-punctate appearance. It 

 seems to be the pliut alluded to by M. Lamy, Lich. Mt. Dor. p. 75, 



Hab. On rocks in maritime and upland districts. — Distr. Very spar- 

 ingly in the Clannel Islands and X.England — B. M. : Chateau Point, 

 Island of Sark. Gunnerton Crags, Xoilhumberland. 



Form 2. complanata Leight. Lich. F]. cd. 3 (1879) p. 205.— 

 Thallus and apothecia iu an uniform plane, the apothecia innate. — 

 Cromb. Grevillea, xviii. p. 68. 



Differs merely in the thallus and apothecia Ijeing smoothed dowii to the 

 same level, but is connected with the type by intermediate states, and no 

 doubt depends upon the nature of the substratum. Leighton describes 

 the apothecia as blackish ; but this is accidental, and in other specimens 

 referable to this form they are of the normal colour. 



Hah. On slate-rocks in maritime districts. — Distr. Only sparinglv in 

 S. Wales, the W. Highlands of Scotland, and S.E. Ireland.— B. M. : Near 

 Towj-n, Pembrokeshire. Baliachulish, Argyleshire. Kinsale, co. Cork. 



Tar, /5. inflexa Johns. e:e Cromb. Grevillea, xviii. (1890) p. 68. — 

 Thallus rimoso-arcolate, greyish-white. Apothecia plane, crowded ; 

 the thalliue margin prominent, thickish, snow-white, crenate and 

 flexuose. 



A distinct variety characterized by the thalliue margin of the apothecia. 

 These are for the most part aggregate and become angulose through 

 mutual pressui-e. It is scarcely- referable to var. ruyosa (Ach.) Fr. til. 

 Lich. Scand. p. 271. 



Hah. On quartzose rocks in an upland district. — JJistr. \ erx local in 

 N.W. England. — B. M. : Alston, Cumberland. 



Var. y. Swartzii Xyl. Lich. Scand. (1861) p. 159. — Thallus un- 

 equal, rimose or verrucoso-granulate, subradiate or at times byssino- 

 radiate at the circumference. Apothecia subglobose, usually aggre- 

 gato-congiomerate, the thalline margin at length evanescent. — 

 Cromb. Lich. Brit. p. 50 ; Leight. Lich. Fl. p. 216, ed. 3, p. 205.— 



