LECANORA | LECANORACEX 279 
large, generally more than 1 mm. across, crowded and difform, 
the disc deep purple-brown, with a white prominent persistent 
margin becoming crenulate.—Lecanora sarcopsis var. marina 
Wahlenb. ex Sommerf. Fl. Lapp. Suppl. p. 91 (1826). 
Hab. On sea piles, etc.—B. M. Mersea Island, Essex (collected by 
P. Thompson). 
Var. Crombiei Johns. Exsicce. n. 263 (1897).—Thallus whitish- 
cinerous, granular, deeply cracked-areolate. Apothecia small, 
crowded, angular, the margin prominent, entire, becoming 
crenulate. 
Exsice. Johns. n. 263. 
Hab. On a decorticate stump.—B. M. Near Bolam, Durham (the 
only locality). 
22. L. umbrina Massal. Ric. Lich. Crost. p. 10 (1852) pro 
parte; Nyl. in Bull. Soc. Bot. xiii. p. 369 (1866).—Thallus 
effuse, thinnish, granulate, unequal, greyish or dark (K-—). 
Apothevia generally umber- or dark-brown, not pruinose, small, 
the thalline margin crenulate or entire, persistent ; paraphyses 
slender, coherent, irregularly septate and slightly clavate or 
capitate, the epithecium of brown granules; spores ellipsoid, 
8-12 » long, 5-6 » thick.—Carroll in Journ. Bot. v. p. 255 
(1867) ; Cromb. Lich. Brit. p. 51 pro parte & Monogr. i. p. 423 ; 
Leight. Lich. Fl. p. 207 pro parte; ed. 3, p. 191 pro parte; 
f. subdistans Nyl. ex Cromb. in Journ. Bot. viii. p. 97 (1870). 
L. Hageni f. calcigena Ny]. ex Cromb. in Journ. Bot. xiv. p. 361 
(1876) & Monogr. i. p. 426; Leight. Lich. Fl. ed. 3, p. 192. 
Lichen umbrinus Ehrh. Crypt. exs. n. 245 (1793) nomen nudum. 
Exsice. Johns. n. 262 (as f. subdistans), 369; Larb. Lich. 
Hb. (without a number). 
Closely allied to L. Hageni, differing only in the somewhat stouter 
more persistent apothecial margins and in the generally saxicolous 
habitat. The thallus is sometimes very dark owing to the development 
of dark-brown hypothallic filaments or to the presence of blue-green 
alge. 
Hab. On siliceous or calcareous rocks, rarely on the ground or on 
palings.—Distr. Wide-spread but less common than the previous 
species.—B. M. La Moye, Jersey; near Penzance, Cornwall; Banner- 
down, Wilts; Aberdovey, Merioneth; Ayton, Cleveland, Yorkshire ; 
Wastdale and St. Bees, Cumberland; Ravensmouth, Durham; Bareal- 
dine, Argyll; Bay of Nigg and Portlethen, Kincardineshire ; Cliffs of 
Moher, Clare; Killery Bay and Lettermore, Connemara, Galway. 
23. L. crenulata Hook. in Sm. Engl. FI. v. p. 190 (1833) ; 
Nyl. in Not. Sillsk. Faun. & Fl. Fenn. Férh. 1866, p. 181.— 
Thallus very thin, effuse, greyish-white, often scarcely visible 
(K—). Apothecia small, scattered, the disc yellow- or dull- 
brown, sometimes pruinose, the thalline margin prominent, 
becoming deeply crenulate, white ; paraphyses coherent, thickish 
