192 LKCANO-LKCIDEEI | lUIlZOCAUPON 



convex ; hypothallus very dLstiiict, often predomiuatini,'. Apothecia 

 plane or tumid, situated between the areohe. — Mudd Man. /. c. 

 Lichen atrovirens L. Sp. PI. p. 1607 (1753); Huds. ¥1 Angl. 

 ed. 2, p. 525 ; Lightf. I. c. ; With. I. c. Lccldea atrovirens Hook. 

 Fl. Scot. /. c. ; S. F. Gray Nat. Arr. i. p, 465. Lecidea geo- 

 graphica var. atrovirens Schter. Spicil. /. c. ; Croml). Lich. Brit, 

 p. 1)3 & Journ. Linn. Soc. xxi. t. D, f. 4 (1886); Lcight. Lich. 

 Fl. p. 346 ; ed. 3, p. 373. 



Perhaps only a less developed thalline condition of the species. 

 When the areol^E are thinly scattered and the hypothallus pre- 

 dominates it is f. prototliallina Koerb. [1. c). The spermogones are 

 more frequent than w^hen the thallus is more developed, the 

 spermatia cylindrical, nearly straight. 



Hah. On rocks and boulders (calcareous excepted) in maritime and 

 mountainous districts. — Distr. No doubt similar to that of the species, 

 though seen from comparatively few localities, chiefly in Scotland. — 

 B. M. Roughton, Cornwall ; Ben-y-gioe, Blair Atholc, Perthshire ; 

 Portlethen, Kincardineshire ; Morrone, Braemar, Aberdeenshire ; 

 Hills of Applecross, Rossshire ; Letter Hill, Connemara, Galway. 



Yar. lecanorinum Floerke ex Koerb. Z. c. — Thalline areolae, 

 somewhat discrete and convex. Apothecia immersed in the 

 areolae, with a sj)urious margin ; spores usually halonate, 

 submuriform 0,030-40 mm. long, 0,011-16 mm. thick. — Lecidea 

 geographica var. cyclopica Nyl. Lich. Scand. p. 248 (1861); Leight. 

 Lich. Fl. Z. c. ; f. cyclopica ed. 3, p. 374. 



ExsicG. Johns, n. 398. 



Well distinguished by the somewhat longer spores and by the 

 character of the apothecia, which are single in each of the areolae and 

 appear as if lecanoroid from the spurious thalline margin. 



Hah. On slate rocks. — Distr, Rare in upland or mountainous 

 districts in N. England and the Grampians, Scotland. — B. M. 

 Lakeside, Ennerdale, Cumberland ; Morrone, Braemar, Aberdeenshire. 



Var. geronticum Th. Fr. Lich. Scand. p. 622 (1874).— Thalline 

 areolae subplane or convex, scattered or subcontiguous, somewhat 

 rugose, v/hite, subpulverulent. Apothecia plane, immersed in 

 the areolae. — Lecidea atrovirens var. gerontica Ach. Meth. p. 45 

 (1803). L. geographica var. gerontica Nyl. Lich. Scand. p. 248 

 (1861) ; Cromb. Lich. Brit. Z. c. ; Leight. Lich. Fl. p. 347 ; ed. 3, 

 p. 374. 



AVell characterized by the colour of the more or less pulverulent 

 thallus, whence Schserer (Spicil. pp. 124, 193) termed it var, 

 'pulveridcntoj. It is rather interesting as being the only state of the 

 species which occasionall}^ occurs on a calcareous substratum. 



Hah. — On quartzose, occasionally calcareous, boulders and stones 

 in mountainous regions. — Distr. Rare on the Grampians, Scotland. — 

 B. M. Morrone, Braemar, Aberdeenshire ; Ben Nevis, Rossshire. 



7. Rh. viridiatrum Koerb. Syst. Lich. Germ. p. 262 (1855). — 

 Thallus greenish-yellow, indeterminate, granular-areolate, the 



