424 LICHENACEI. [LECANORA. 
hymenial gelatine bluish, then tawny-wine-coloured or violet with 
iodine.—Carroll, Journ. Bot. 1867, p. 255; Cromb. Grevillea, xviii. 
p. 68; Lich. Brit. p. 51, pro parte; Leight. Lich. Fl. p. 207, ed. 3, 
p. 191.—Lichen umbrinus Ehrh. Crypt. (1793) n. 245. 
Easily recognized in this subsection by the colour of the apothecia. 
The thallus, which is usually indeterminate, varies somewhat in thickness 
according to the habitat. Rarely it is more or less scattered over the 
substratum and little developed (clive-brownish hypothalline), when it 
is forma subdistans Nyl. ex Cromb. Journ. Bot. 1870, p. 97. The apo- 
thecia are at times subbiatorine. The spermogones have the spermatia 
semicircular, 0,015-22 mm. long, 0,0005 mm. thick. 
Hab. On rocks, occasionally on old pales, rarely on the ground in 
maritime and upland districts.—Dvstr. Only here and there in Great 
Britain, Ireland, and the Channel Islands—B. M.: La Moye, Island of 
Jersey. Lamorna Cliff, Penzance, Cornwall; Lydd, Kent; Aberdovey, 
Merionethshire; Ayton, Cleveland, Yorkshire. Barcaldine, Argyleshire ; 
Blair Athole, Perthshire; Portlethen and Bay of Nigg, Kincardineshire. 
Cliffs of Moher, co. Clare; Killery Bay, Connemara, co. Galway. 
104. L. crenulata Nyl. Not. Sillsk. pro F. et Fl. Fenn. Forh. 
n.s. v. (1866) p. 181; Flora, 1872, p. 250.—Thallus effuse, very thin, 
often scarcely visible, greyish-white (K—, CaQl—). Apothecia 
small, scattered, brownish-grey, at times ceesio-suffused ; the thal- 
line margin whitish, deeply crenulate; paraphyses thickish, jointed, 
brownish at the apices; spores 0,010-16 mm. long, 0,005-7 mm. 
thick ; hymenial gelatine bluish, then wine-coloured with iodine.— 
Sm. Eng. Fl. v. p. 190 pro parte.—ZL, umbrina subsp. crenulata 
Cromb. Grevillea, xii. p. 59, form crenulata Cromb. Lich. Brit. p. 51, 
Leight. Lich. Fl. p. 207, ed. 3, p. 191. JZ. albella 6. erenulata 
Mudd, Man. p. 148. Lichen crenulatus Dicks. Crypt. fase. iii. 
(1798) p. 14, t. 9. f. 1; Eng. Bot. t. 930; With. Arr. ed. 3, iv. 
p.17. According to a specimen from his own Herb. this is also 
L. galactina (3. disperso-areolata (non Schaer), Mudd, Man. p. 149, 
—Brit. Exs.: Larb. Lich. Hb. n. 258. 
Frequently confounded with subsp. dispersa of L. galactina, but distinct 
in the character of the paraphyses and in the smaller spores, as pointed 
out by Nylander, who first definitely discriminated between them. From 
the preceding species it is distinguished by the tessellato-crenate margin 
of the apothecia,—the crenulations being deeply divided and separated 
by a furrow, though in abraded specimens this character is scarcely 
apparent. It differs also from it in the size of the spermatia, which (fide 
Nyl. in litt.) are 0,011-15 mm. long, 0,0005 mm, thick. 
Hab, On calcareous, rarely sandstone, rocks in maritime and upland 
situations.—Distr. Seen only from a few localities in SW. and N. England, 
the Grampians, Scotland, and N.W. Ireland.—B, M.: Watcombe Bay, 
8. Devon; Alfrick, Worcestershire; near Ayton and Carlton Ban 
Cleveland, Yorkshire; Fglestone, Durham; Lamplugh, Cumberland ; 
Teesdale, Durham. Craig Tulloch, Blair Athole, Perthshire; Craig 
Guie, Braemar, Aberdeenshire, Oughterarde, co. Galway. 
