CETEAKIA.] CETRARIEI. 21!) 



Form 2. acanthella Xyl. ^ilura. 8oc. Cherb. v. (1857) p. 100. — 

 Thallus as in the type, but very much spinuloso-denticulate throuf^h- 

 out. Apothecia few. — Cromb. Journ. Bot. 1870, p. OG; Leif^ht. 

 Lich. Fl. p. !)8, ed. 3, p. *J3. — Cornicularia sjiadicea y. acanthella 

 Ach. Lich. Univ. (1810) p. (512. Conilluidcs fruticufi specie fuscuin, 

 spinosum DiU. Muse. 112, t. 17. f. 31 ii. 



Distinguished by the entirely bispido-spinulose or setulose thallus. In 

 this country the a]iothecia are very rare. The spermogoues are frequently 

 present iu herbaria specimens. 



Hab. On the ground among mosses in upland districts. — Di.'<fr. Local 

 and scarce in W. and X. England, X. ^^'ales, and among tlie X. Gram- 



?ians, Scotland. — B. M. : Clifton, near Bristol; Dolgelly, Merionetiishire ; 

 'arndale, Yorkshire; Prestwick Carr, Xortluimberlaiid. Clova Mts., 

 Forfarshire; Hill of Ardo near Aberdeen, S. of Luchuagar, Braemar, 

 Aberdeeushii-e ; Glen Xevis, Inverness-shire. 



5. C. odontella Ach. Syn. (1814) p. 230.— Thallus densely fru- 

 ticuloso-caespitose, depressed, narrowly laciniate: lacinia' plane, linear, 

 thin, palmately ramoso-divided, spinulose at the margins, spadiceous, 

 chestnut-brown or pale spadiceous, paler at the base, or sometime.s 



blood-coloured (K~, CaCl~). Apothecia terminal, concolorous, 



the margin denticulate ; spores 0,007-010 mm. long, about 0,0045 

 mm. thick. — Cromb. Journ. Bot. 1882, p. 272, — Lichen odontellus 

 Ach. Prodr. (1798) p. 213. 



This usually forms minute depressed tufts, and somewhat resembles form 

 hispida of the preceding species, but is distinguished by the plane thiu 

 laciuiae. The thalhis closely allies it to C. cri.spa, from which it is, however, 

 separated by tlie characters given. In the only specimen found in this 

 country, apothecia and spermogones are absent. 



Hah. Among mosses on rocks in alpine tracts. — Distr. A single 

 specimen from the X. Grampians, Scotland. — B. M. : Cairntoul, Braemar, 

 Aberdeenshire. 



40. PLATYSMA Xyl. Mem. Soc. Cherb. v. (1857) p. 100; Syn.i. 

 p. 'Sol.—PIatisina, Hoffm. Deutsch. Fl. ii. 



(1795) p. 138 pro minima parte (ut sectio Lo- ^^^ nS^" 



bance). — Thallus fruticulose or membranaceo- %^ ^:!^, 



dilated, erect, ascending or appressed, more or (, m]i: 

 less rigid, lobed or laciniate, concolorous on both 

 sides or discolorous ; medullary layer with the 

 filaments loosely interwoven ; cortical layer more 



or less cellular, very rarely with tubulose cavities. : «??? ^ ^ 



Apothecia discolorous from thallus, marginal ' ' "^ ""'"'• 



or submarginal, rarely adnate on the back of pj' ^3 



the apices of the lacinice, the margin entire or p/«/^,,„« connnixfum 



crenulate; hypothecium colourless; spores sub- ]S\vl.— a. Section of 



ellipsoid; hymenial gelatine bluish with iodine. upper portion of the 



Spermogones marginal, globulose : sterigmata thallus, x2U0. b. 



somewhat simple or pauci-articulate ; sper- vertical section of a 



^ ^ ,. 1 • IN ^ spermogone. xSLl 



matia various (not cylindrical). o. fc^terigmata and 



spermatia, xi)()0. 





