LICHENES 435 



Far. b. Atlantica, Tuckerm. gubmembranaceous, lacunoee-rcticulatc, apothecia 

 becoming perforate. 

 JIa.lt. On rails and trunks of trees : common. The var. only, found. 



4. C. aursccns, Tuckerm. [Golden] : Thallus subcoriaceous, 

 foliaceous, plane, sinuate-lobed, yellowish-green ; beneath whitish 

 with pale fuscescent fibres ; margins of the lobes elevated, crisped, 

 black-denticulate ; apothecia large, elevated, chestnut, with a thin 

 crenulate margin. 

 Hob. On fences, &c. : rare. 



Obs. In the specimen before me, the apothecia are small (imper- 

 fect?), the thallus lacunose beneath, and the fibres mostly white. 



SUB-TRIBE 2. PARMELIE^AE. 



DitJc at first closed, linaily becoming discoid-open; Viullus horizontal, centrifugal, 

 with a hypctbailus. 



595. X EPII'RODIA. Ach. 



[Gr. Ncphros, n kidney, and nmos, like ; from the shape of the apothecia.] 

 Apothecia reniform, adnate to the under side of the thallus, plane, 

 with an elevated thallinc margin. Thallus membranaceous, soft, 

 subvilluuj beneath. 



1. HT. rcsupln^ium, Ach. [Resupinate]: Thallus cartilagin- 

 eous-membranaccoua, smooth, glaucous becoming fuscescent, pale 

 and downy beneath, with scattered whitish soredia ; apothecia 

 rufous-fuscous. 



Hab. Trunks of trees (often on Mountain Ash); rocks, Ac. 



2. W. IlelVt'tfClim? Ach. [wtw]: Thallus cartilagineous- 

 membrauaceous, rigid, glaucous-fuscescent ; underside tomentose, 

 becoming black; margins of the thallus and apothecia fimbriate- 

 toothed; apothecia blackish. 



Hob. On mo-sHy trunks of trees, and rocks. 



Obs. I have only seen a small sterile form, which renders the 

 species somewhat uncertain. 



596. PEI/TI'GERA, Iloffm. 



[Latin, Pdla, a shir-Id, uud gc.ro, to bear; descriptive of the plant.] 

 Apothecia orbicular, peltacform, plane, subterminally adnate to the 

 upper side of elongated thalline lobes, with a thin thalline margin. 

 Thallus coriai eous-membrauaceous, venous beneath. 



1. P. aplitll jsa, Iloffm. [Aphthous~\: Thallus coriaceous, smooth, 

 sparsely verrucose, bright green varying to glaucescent ; under 

 side reticulate with blackish veins, and fibrillose ; apothecia ascen- 

 dant, large, round, with the margin lacerate-crenate. 



Hob. Mossy rocks, and shaded banks; common. 



2. P. cailina, Iloffm. [Canine]: Thallus membranaceous, 

 flaccid, scrobiculate, subtomentose, fuscous-green, sometimes ciner- 

 ascent, and hoary ; under side whitish, reticulated with pale fus- 

 cous veins ; apothecia ascendant, rounded, revolute, vertical. 



Hab. Among moss, on the earth, rocks, and trunks of trees : common. 



