LECANORA | LECANORACEX: 329 
mouth, Merioneth; Beddgelert, Trefriw Falls and Carnedd Dafydd, 
Carnarvonshire; Teesdale, Durham; Appin and Glencoe, Argyll; 
near the Trossachs, Glen Falloch and Ben Lawers, Perthshire ; Glen 
Callater, Braemar, Aberdeenshire; Invermoriston, Invernessshivre ; 
Ballaghbeama Gap, Dunkerron, and Connor Cliffs, Dingle, Kerry ; 
Ballynakill and Lough Inagh, Connemara, Galway; Clare Island, 
Mayo. 
87. L. Dicksonii Nyl. ex Carroll in Journ. Bot. iv. p. 255 
(1867).—Thallus thin, plane and smooth, finely cracked-areolate, 
rusty or yellowish-red, with a thin black hypothallus (K—-, 
CaCl—). Apothecia small, innate, becoming superficial, the dise 
concave, black, with a prominent black rim, the thalline margin 
very indistinct as an outer reddish covering; hypothecium 
dark-brown ; paraphyses coherent, slender, straight or flexuose, 
septate, the epithecium bluish- or brownish-black ; spores ellip- 
soid, 11-14 yp long, 6-8 p» thick; hymenial gelatine blue with 
iodine.—Cromb. Lich. Brit. p. 55 & Monogr. i. p. 476: Leight. 
Lich. Fl. p. 211; ed. 3, p. 196. Lichen cxsius Dicks. Pl. Crypt. 
fase. ii. p. 19, t. 6, fig. 6 (1790)? (non Hoffm.). L. Dicksonii 
Ach. Lich. Suec. Prodr. p. 76 (1798) ; With. Arr. ed. 3, iv. p. 20. 
L. Oederi With. op. cit. p. 11 (1796) pro parte (non Web.) ; 
Sm. Engl. Bot. t. 1117. Lecidea Oederi Wahlenb. Fl. Lapp. 
p-. 474 (1812) ; S. F. Gray Nat. Arr. i. p. 465; Hook. Fl. Scot. ii. 
p. 38 & in Sm. Engl. Fl. v. p. 178; Tayl. in Mackay EY Hib: a. 
pe lees ede melanopheea Fr. in Vet. Akad. Handl. 1822, p. 259 ; 
Mudd Man. p. 206. 
Exsicc. Cromb. n. 72; Dicks. Hort. Sicc. fase. ii. n. 24; 
Johns. n. 149 ; Leight. n. 127. 
Of doubtful systematic position, with perhaps more affinity with 
Lecidea than with Lecanora. The apothecia take rise within the 
thallus and gradually emerge; they are numerous and sometimes 
confluent, so that the dise may appear to be lined or dotted. The 
rusty colour is fairly constant, but, as in some other lichens, is generally 
considered to be due to the infiltration of ferric hydrate, though, as 
has been pointed out by Wheldon and Wilson (Lich. Perth. p. 42), the 
species sometimes grows on white quartz where it exhibits the same 
bright colour. Specimens from Kerguelen Land with a grey thallus 
have been recorded by Crombie as Lecidea sincerula Nyl. (Linn. Soc. 
Journ. Bot. xv. p. 190 (1877) ).. The species has been confused with 
Rhizocarpon Oederi, but it differs in the prominent proper margin of 
the apothecium as well as in spore characters. 
Hab, On rocks and walls chiefly schistose, in upland or moun- 
tainous regions.—Dzistrv. Not uncommon in hilly districts of the 
British Isles.—B. M. Fingle Bridge, near Chagford, Devon; Bar- 
mouth, Dolgelly and Rhiwgreidden, Merioneth; Bettws-y-Coed, 
Denbighshire; Cwm Trefayn, Snowdon, Carnarvonshire; Anglesea ; 
Wrekin Hill, Shropshire; Staveley, Kendal, Westmoreland; Lam- 
plugh and Ennerdale, Cumberland; Ben Lawers and Craig Tulloch, 
Blair Athole, Perthshire; Glen Callater and Morrone, Braemar, 
Aberdeenshire ; Applecross, Rossshire; Crogham (? Cloghane) and 
Mangerton, Killarney, Kerry. 
