318 LICHENACEI. [PHY6CIA. 



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 

 Kcndal, 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. Laciniae 

 narrower, more discrete, somewhat convex ; otherwise as above. 

 Parmelia casia ft. teretiuscula Ach. Lich. Univ. (1810) p. 479. 



Differs from the type only in the minor characters of the lacinia?, and 

 intermediate states are not wanting. The British specimens are sterile. 



Sab. On rocks in maritime and mountainous districts. Distr. Seen 

 only from W. England and S.W. Ireland. B. M. : Penzance, Cornwall ; 

 Malvern, Worcestershire ; Dunkerron, co. Kerry. 



21. P. obscura Nyl. Act. Soc. Linn. Bord. ser. 3, i. (1856) p. 309. 

 Thallus orbiculari-stellate, closely appressed and adnate, dark or 

 greyish-brown : beneath black-fibrillose ; latinise narrow, plane or 

 slightly convex (K~, CaCl~). Apothecia sessile, small, blackish- 

 brown, naked, the margin entire ; spores ellipsoideo-obloug, 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 cijcloselis 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. Exs. : 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 latinise en'brillose. 

 The form chloantha (Ach. Syn. p. 217), with ' pale-greyish thallus and 

 laciniae lacerato-dentate at the margins," has not yet occurred with us, 

 though recorded by Leighton, I. c., as British. In our specimens the 

 ap_othecia are fairly numerous. The sperm ogones are more frequent, 

 with spermatia oblong, 0,003 mm. long, about 0,001 mm. thick. 



Hob. On the trunks of trees in upland situations. Distr. Seen only 

 from a very few localities in England and the S. Grampians, Scotland ; no 

 doubt frequent but overlooked. B. M. : Brockenhurst, New Forest, 

 Hants ; near Cambridge ; near Ledbury, Herefordshire. Finlarig, Killin, 

 Perthshire. 



22. P. lithotea Kyi. Flora, 1877, p. 354. Thallus orbicular, 

 appressed, narrowly laciniate, glaucous- or dark-brown, furfuraceo- 

 or granuloso-sorediate ; beneath black-fibrillose ; laciniaB plane, 

 closely imbricate, subciliate at the margins (K~, CaCl~). Apo- 

 thecia central, blackish ; spores as in the preceding species or slightly 



