PLATTSMA.] CETRAKIEI. 223 



(K~ e ii ow i 8 h' CaCl~). Apothecia moderate, brownish-red, the 

 receptacle externally plicato-rugose, the margin granulate ; spores 

 ellipsoid, 0,005-11 mm. long, 0004-6 mm. thick. Cromb. Lich. Brit, 

 p. 27 ; Leight. Lich. Fl. p. 101, ed. 3, p. 95. Parmelia Fahlunensis 

 Ach., Gray, Nat. Arr. i. p. 441 ; Hook. Fl. Scot. ii. p. 53 ; Sm. Eng. Fl. 

 v. p. 206 ; Mudd, Man. p. 100 pro parte. Lichen Fahlunensis Ach. 

 Prodr. (1798) p. 1 10 ; Huds. Fl. Angl. ed. 2, p. 532 pro parte ; Eng. 

 Bot. t. 653 (descript. non fig.) ; With. Arr. ed. 3, iv. p. 30 pro parte. 

 Lichenoides tinctorium atrum, foliis minimis crispis Dill. Muse. 188, 

 t. 24. f. 8 1 . The specimens in Herb. Linn, named Lichen Fahlu- 

 nensis belong to the next species, as do specimens in the Herbaria of 

 our older authors. To prevent the greatest confusion I have used 

 the name applied by Acharius to this plant, and by which it has 

 been usually designated. 



The thallus is parmelioid, occasionally somewhat expanded, with the 

 lacinise more or less subascendinjr. The apothecia are elevated, at first 

 urceolate, at length becoming somewhat plane. The spermogones are 

 frequent, brownish-black, in protuberant marginal papillae, with spermatia 

 slender, elongate, 0,005 mm. long, 0,001 mm. thick. 



Hob. On rocks and boulders in subalpine and alpine places. Distr. 

 Local and scarce in S., W., and N. England, and N. Wales; more frequent 

 among the Grampians, Scotland, especially in Braemar ; not seen in 

 Ireland. B. M. : Hay Tor, Dartmoor, Devonshire ; Cader Idris, Merio- 

 nethshire ; The Cheviots, Northumberland. Ben More and Ben Lawers, 

 Perthshire ; Clova Mts., Forfarshire ; Lochnagar, Ben Macdhui, Aber- 

 deenshire ; Ben Nevis, Inverness-shire. 



7. P. polyscMzum Nyl. Flora, 1862, p. 82 (not.), 1869, p. 442. 



Thallus orbicular, appressed, thickish, smooth, laciniato-divided, 

 greyish- or dark-olive-brown, beneath paler or dark ; laciniae short, 

 narrow, imbricately crowded, subcanaliculate, slightly elevated at the 

 margins, and rotundato-crenate at the apices (K~, CaCl~). Apo- 

 thecia and spores as in the preceding species. Cromb. Journ. Bot. 

 1882, p. 272. 



This might be taken for a panniform condition of P. Faliluneme, with 

 which it agrees in the form of the spermatia, but it is at once separated 

 by the absence of any reaction of the medulla. The thallus when mois- 

 tened is of a greenish colour, and varies beneath from osseous-white to 

 dark-spadiceous. In perfect specimens the laciniae are broader, planer, 

 and less divided at the extreme circumference. When fertile the apo- 

 thecia and spermogones are occasionally numerous and crowded. 



Hab. On rocks and boulders in alpine places. Distr. Extremely local 

 and scarce on one of the higher N. Grampians, Scotland. B. M. : Ben- 

 naboord, Braemar, Aberdeenshire. 



B. Spermatia ellipsoid. Thallus subascending, closely affixed, sub- 

 concolorous ; lacinias rather narrow. 



8. P. commixtum Nyl. Syn. i. (1860) p. 310, t. 8. f. 33. Thallus 

 suborbicular, adpresso-imbricate, smooth, laciniate, spadiceous or 

 spadiceo-brownish, beneath nearly concolorous, with a few rhizinae 



