PARMELIA. | PARMELIEI. 237 
receptacle reticulato-verrucose, the margin incurved, verrucose ; 
spores 6—-8nex, 0,016-19 mm. long, 0,008-11 mm. thick.—Cromb. 
Journ. Bot. 1876, p. 860.—Purmelia endochlora, Leight. Lich. FI. 
(1871) p. 140, ed. 3, p. 183. Parmelia McMillana, Stirt. Grevillea, 
iil. p. 79.—Indicated by Nylander (Flora, 1869, p. 290) as a variety 
of P. comparata, to which it is closely related. I have therefore 
retained his specific name in preference to that of Leighton, whose 
diagnosis of the plant is misleading. 
Distinguished from the preceding by the colour of the medulla. The 
thallus is smooth and unequal, thin or moderate, often whitish-sorediate 
at the apices of the lobes, the soredia becoming dark-greyish inage. The 
reaction of the medulla with K, which is pale yellowish (not ‘ yellowish- 
brown,” Leight.), is especially seen under the microscope. It is very rarely 
fertile in this country, the apothecia becoming very large, with the thalline 
margin obliterated. : 
Hab. On rocks and boulders in shady wooded upland districts.—Distr. 
Local and scarce in N. Wales, the S.W. Highlands, Scotland, and W. 
Ireland—B. M.: Nannau, Dolgelly, Merionethshire; Glen Croe and 
Barcaldine, Argyleshire. Askew Wood, Dunkerron, co. Kerry (frt.) ; 
near Kylemore, co. Galway. 
7. P. revoluta Nyl. Bull. Soc. Linn. Normand. sér. 2, iii. (1868) 
p. 264.—Thallus orbicular, moderate, smoothish, narrowly sinuato- 
lobed, glaucous-white or whitish; beneath blackish-fibrillose, at 
length nearly glabrous, the lobes cucullato-revolute and usually 
: a +yellowish - 
tuberculato-sorediate at the apices (KT! » CaCl) eadish): 
Apothecia nearly moderate, badio-reddish, the margin entire or 
obsoletely crenate; spores 6-8ne, 0,011-19 mm. long, 0,007-12 
mm. thick.—Cromb. Grevillea, xv. p. 75.—Parmelia tiliacea var. 
revoluta, Leight. Lich. Fl. p. 132, ed. 3, p. 129. Imbricaria revo- 
luta, Florke, D. Lich.(1815) p. 15.—To this also are referable Parmelia 
levigata var. subsinuosa, Leight. Lich. Fl. ed. 3, p. 129, and P. é2li- 
acea var. sublevigata Leight. Lich. Fl. p. 132, ed. 3, p. 122.—P. sub- 
hevigata Nyl. is an exotic species, which does not occur in Europe. 
—Brit, Exs.: Leight. n. 202 (s.n. P. Forstert Borr.), n. 357 ; Mudd, 
n. 68; Larb. Lich. Hb. n. 293. 
Distinguished from P. levigata by the cucullato-revolute apices of the 
narrower and more approximate lobes, by the chemical reaction of the 
medulla with CaCl alone, and by the larger spores. These characters 
warrant us in regarding it as a species, and not as a variety of P. levigata. 
The tuberculose soredia, with which the apices of the lobes are frequently 
covered, are whitish, becoming in age dark-greyish. In this country it is 
but very seldom seen in fruit. The spermogones are as in the former 
species. 
Hab. On rocks and trees among mosses in maritime and mountainous 
districts — Distr. General, but not common in S., W., and N. England ; 
rarer in S. Scotland and the W. Highlands, as also in W. Ireland; rare 
in the Channel Islands.—B. M.: La Coupe, Island of Jersey. St. Leo- 
nards Forest, Sussex ; Isle of Wight; near Lyndhurst and Bournemouth, 
Hampshire; Ilsham, Torquay, Ullacomhe, near Bovey Tracey, and Lyn- 
ton, Devonshire; Withiel and Penzance, Cornwall; Aberdovey, Bar- 
