LECANORA. | LECANO-LECIDEEI, 403 
section of Lecanora, The thallus is rather scattered, greenish-grey when 
moistened, usually but sparingly fertile; though in one corticolous frag- 
ment the apothecia are somewhat numerous. 
Hab. On mossy and naked trunks of trees in upland situations.—Distr. 
Extremely local and scarce in N. Wales, where it has not recently been 
met with.—B, M.: Cwm Bychan and Crafnant, Merionethshire. 
D. Thallus placodioid. Apothecia lecanorine; spores 8u2, ellipsoid, 
rarely subglobose, simple, colourless; paraphyses jointed. 
Spermogones with simple or shortly jointed sterigmata and 
cylindrical, moderate, straight spermatia. 
77. UG. melanaspis Ach. Lich. Univ. (1810) p. 427; Nyl. Flora, 
1873, p. 18, nota.—Thallus suborbicular, adnate, thinnish, areolate 
or verrucoso-rugose in the centre, radiato-laciniate at the circum- 
ference, greyish or leaden-greyish, the radii convex, multifid (K—, 
CaCl—). Apothecia small, appressed, plane, at length convex, the 
thalline margin entire; spores ellipsoid, 0,011-13 mm. long, 
0,008-10 mm. thick; hymenial gelatine bluish, then wine-red with 
iodine.—Leight. Lich. Fl. ed. 8, p. 201.—Lecanora alphoplaca var. 
melanaspis Stirt. Scottish Naturalist, iv. p. 28. 
Differs from L. alphoplaca (Wahl.), the typical species of this section, 
of which it has sometimes been made a variety, and which is not found 
in Britain, in the negative reaction with K, among other distinctive cha- 
racters of the thallus and apothecia. I have, however, seen no British 
specimen, and regard it as of doubtful occurrence in the locality re- 
corded. 
Hab. On rocks in a mountainous region.—Distr. Said to have been 
found in the 8.W. Highlands of Scotland (Ben Brecht, Argyleshire). 
78. L. cireinata Ach. Lich. Univ. (1810) p. 425—Thallus orbi- 
cular, closely adnate, verrucoso-areolate in the centre, radiato-plicate 
at the circumference, greyish or greyish-white, the radii contiguous, 
narrow, somewhat plane or convex (K — or + yellowish). Apothecia 
small or submoderate, innate, at first suburceolate, then plane, 
brown or dark-brown, the thalline margin thin, entire; spores ellip- 
soid, 0,011-15 mm. long, 0,0065-85 mm. thick; hymenial gelatine 
bluish, then reddish with iodine.—L. circinata Cromb. Lich. Brit. 
p. 49; Leight. Lich. Fl. p. 195, ed. 8, p. 179; Hook. Fl. Scot. ii. 
p. 50. Squamaria circinata Mudd, Man. p. 180; Sm. Eng. Fl. v. 
p. 196. Placodium circinatum Gray, Nat. Arr. i. p. 448. Lichen 
circinatus Pers. in Ust. Ann. Bot. vii. (1794) p. 25, Eng. Bot. t. 
1941.—A well-marked species, of which the type apparently does 
not occur in Britain, but only the peculiar form subcircinata Nyl. in 
litt., differing merely in the thalline reaction (K+yellow, then 
saffron-red); This being but a supplementary reaction, the plant 
is not now regarded by Nylander as constituting a distinct species as 
in Flora, 1873, p. 18, subsp. Cromb. Grevillea, xvili. p.47.—Lichen 
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