318 LICHENACEI. [PHYsCIA. 
land; rare in the Channel Islands and N. Wales; not seen from Ireland. 
—B. M.: Island of Guernsey. Acle, Norfolk; Walthamstow, Essex ; 
Richmond House, Surrey; Withiel and near Penzance, Cornwall; near 
Oxford; Twycross, Leicestershire; near Harboro’ Magna, Warwick- 
shire; Buxton, Derbyshire; near Oswestry, Shropshire; Barmouth, 
Merionethshire ; Ayton, Cleveland, Yorkshire; Teesdale, Durham; near 
Kendal, Westmoreland; near Hexham, Northumberland. New Gallo- 
way, Kirkcudbrightshire; near Edinburgh; Kirkfield, Lanarkshire ; 
Appin, Argyleshire ; Dunblane, Perthshire; Craig Tulloch, Blair Athole, 
Perthshire; Crathie, Braemar, Aberdeenshire. 
Form teretiuscula Nyl. Lich. Scand. (1861) p. 112.—Lacinie 
narrower, more discrete, somewhat convex ; otherwise as above.— 
Parmelia cesia B. teretiuscula Ach. Lich. Univ. (1810) p. 479. 
Differs from the type only in the minor characters of the laciniz, and 
intermediate states are not wanting. The British specimens are sterile. 
Hab. On rocks in maritime and mountainous districts — Distr. Seen 
only from W. England and 8.W. Ireland.—B. M.: Penzance, Cornwall ; 
Malvern, Worcestershire ; Dunkerron, co. Kerry. 
21. P. obscura Nyl. Act. Soc. Linn. Bord. sér. 3, i. (1856) p. 309. 
—Thallus orbiculari-stellate, closely appressed and adnate, dark or 
greyish-brown; beneath black-fibrillose ; lacinia narrow, plane or 
slightly convex (K_, CaCl_). Apothecia sessile, small, blackish- 
brown, naked, the margin entire ; spores ellipsoideo-oblong, 0,015- 
25 mm. long, 0,009-12 mm. thick.—Cromb. Lich. Brit. p. 39; 
Leight. Lich. Fl. p. 148 pro parte, ed. 3, p. 136 pro parte.—Borrera 
obscura Mudd, Man. p. 109 pro parte. Lichen obscurus Ehrh. PI. 
Crypt. (1785) n. 177. Parmelia cycloselis Ach., Gray, Nat. Arr, i. 
p. 444 pro parte; Sm. Eng. Fl. v. p. 202 pro parte. Lichen cyclo- 
selis Eng. Bot. t. 1942.— Brit. Ews.: Larb. Lich. Hb. n. 252. 
In its typical condition, which has seldom been rightly described, the 
thallus is entirely esorediate, with the margins of the laciniv efibrillose. 
The form chloantha (Ach. Syn. p. 217), with “ pale-greyish thallus and 
laciniz lacerato-dentate at the margins,” has not yet occurred with us, 
though recorded by Leighton, J. ¢., as British. In our specimens the 
apothecia are fairly numerous. The spermogones are more frequent, 
with spermatia oblong, 0,003 mm. long, about 0,001 mm. thick. 
Hab. On the trunks of trees in upland situations.—Distr. Seen only 
from a very few localities in England and the 8. Grampians, Scotland ; no 
doubt frequent but overlooked.—B. M.: Brockenhurst, New Forest, 
Hants; near Cambridge ; near Ledbury, Herefordshire, Finlarig, Killin, 
Perthshire. 
22, P. lithotea Nyl. Flora, 1877, p. 354.—Thallus orbicular, 
appressed, varrowly laciniate, glaucous- or dark-brown, furfuracco- 
or granuloso-sorediate ; beneath black-fibrillose; laciniz plane, 
closely imbricate, subciliate at the margins (K—~,CaCl7). Apo- 
thecia central, blackish ; spores as in the preceding species or slightly 
