GRAPHlDEACEiE. 



245 



Not very common, on trees in various localities in Eng- 

 land and Ireland. 



13. Lecidea aurantiaca {aurantiacus, of an orange- 

 colour). Thallus yellowish, leprose or tartareous; hypo- 

 thallus white. Apothecia orange-coloured, thinly margined, 

 younger crowned by hypothallus. The thallus is sometimes 

 evanescent. The apothecia may be innate or sessile, flat or 

 convex, with a more or less prominent margin. 



Comparatively common on various trees, as the poplar 

 and willow, and on various rocks and stones, — especially cal- 

 careous, arenaceous, and granitoid, — in lowland, more rarely 

 in subalpine regions. 



Nat. Ord. IX. GRAPHIDEA CEJE* 



Fam. Char. Apothecia oblong* or lirellate. Thalamiam at first 

 connivent or veiled, oblong, subcanali dilate, normally having a 

 proper or thalline exciple, or both. (Name from ypacj>rj, writing, 

 in allusion to the resemblance of the apothecia, — which are fre- 

 quently irregularly stellate or radiate, — to ancient hieroglyphics 

 or written characters. Eor the same reason the Graphidece are 

 popularly designated " Letter Lichens," or " Scripture-worts.") 



* Bibliography : — Leighton, Monograph of the British Graphidese, in 

 the * Annals of Natural History/ 1854, also published separately : Chevalier, 

 Histoire des Graphidees, 1824, and in the ' Journal de Physique/ Feb., 1822 : 

 Dufour, Revis. du Genre Opegraphe, etc., in the ' Journal de Physique/ 1818. 



