BRITISH LICHENS

LECIDEA LECIDEACE.iE 47
Somewhat like L. leptostigma, but very distinctive on account of the
large spores and the thick uneven thallus, which becomes pitted after
the disappearance of the apothecia. The apothecia are orlginally
descrIbed as Irregularly grouped in small circles, a character not well
marked in our specimen.
Hab. On limestone.-B. lrf. Bathampton Downs, Wiltshire.
64. L. Bauschiana A. L. Sm.-Thallus thin, filmy or furfuraceous,
pale-tawny. Apothecia minute, convex, yellowishbrown
to dark-brown or black; hypothecium brownish-yellow or
colourless in thin section; paraphyses conglutinate, the epithecium
colourless or brownish; spores ellipsoid, minute, 8 1.1. long,
4 1.1. thick or smaller.-L. dilutiuscula Nyl. in Flora lix. 308 (1876);
Leight. Lich. FI. ed. 3, 256 (187n). Biatora' Bauschiana Koerb.
Parerg. Lich. 157 (186), fide N yl. Lich. Env. Paris, 93 (1896).
In the preVIOUS edItion this species had been associated with L.
sylvicola var. indigula. Some of the specimens determined as L.
dilutiuscula are now included here. The thallus and apothecia closely
resemble those of L. sylvicola.
Hab. On schistose rocks.-Distr. Rare in S. England.-B. ltl. Near
Ditcham Cove and ncar Buckfastleigh, S. Devon.
65. L. rusticula Nyl. in Flora xlix. 371 (1866).-Thallus
effuse, granulate, the granules depressed-convex, sub crenate ,
smooth, glaucous-white (K + yellowish, CaCI + yellow). Apothe
cia minute, somewhat plane, margined, black, the margin
entire, at length obliterated; paraphyses concrete; epithecium
vaguely brownish; hypothecium brown; spores ellipsoid, 10-15 1.1.
long, 5-8 1.1. thick; hymenial gelatine deep-blue then sordidyellowish
with iodine.-Leight. in Ann. Mag. Nat. Rist. xix. 407
(1867); Cromb. Lich. Brit. 84; Leight. Lich. Fl. 271; ed. 3, 272.
Considered by Nylander to be related to L. expansa, but the
character of the apothecia indicates its pOSItion in Sect. Biatora. These
are at first concave with an obtuse margin. In the small specimen
seen they are few and scattered. Spermogones have not been detected.
Hab. On quartzose rocks in mountainous districts.-Distr. FQund
only very sparingly in N. Wales and N.W. Ireland (Salrock Road,
Connemara, Galway fide Leight. Lich. Fl. ed. 3 l. c.).-B. jJl. Giant's
Pebbles, Cader Idris, Merioneth.
66. L. rusticella Nyl. in Flora lxi. 245 (1878).-Thallus effuse,
thin, subleprose, whitish-ochraceous (Ie + reddish, CaCI -).
Apothecia minute, convex, immarginate, black, opaque, dark,
within; paraphyses concrete; epithecium and hypothecium
brown or brownish; spores sub oblong, 6-9 1.1. long, 2'5-3'5 1.1. thick;
hymenial gelatine bluish then tawny-wine-red with iodine.­
Cromb. in Grevillea vii. 97; Leight. Lich. Fl. ed. 3, 252.
Exsicc. Johns. n. 504.
Comparable with L. rusticula, but distinct in the character of the
thallus and in the smaller spores. The colour of the thallus, which
:Nylander, l. c., says may be normally greyish, is evidently dUll to
suffusion by peroxide of iron. The apothecia are rather scattered.