78 BERN'T LYNGE. M.-N. Kl. 



loured part of the cortex, especially in the margin of the apothecia, scattered 

 under the hypothecium only, and absent within the black part of the cor- 

 tex. Hypothecium yellowish, thick: up to 105 u, hyphae with narrow lumina, 

 densely interlaced. Disc plane or slightly convex, brownish-black or black, 

 epruinose, covered with a thin amorphous uncoloured stratum. Hymenium 

 at the exterior part pale or dark yellowish-brown, otherwise uncoloured. 

 Paraphyses distinctly septate, unbranched or occasionally furcate, at their 

 apices clavato- or capitato incrassate and constrictedly septate. Asci 

 80 85 jit long, 13 16 it thick, octosporous. Spores obliquely biseriate 

 or parallel to the axis of the ascus, straight, rarely slightly fabiform, not 

 constricted at the septum, with rounded ends. Colour greyish-brown 

 to black, old spores very opaque Cell room usually small and angular. 

 stretched across the thick-walled spore, occasionally large and rounded, leaving 

 only a relatively thin cell-wall. Porous canal distinct. 

 Spores ellipsoidical, their thickness about half the length 

 or a little longer, size 15,7 22(24) it long, 7,4 n 

 thick. 



Fie. 8. Physcia litho'.ea ., .. ., i-ii 



Pycmdes globose or with a slightly prominent upper 

 part; perifulcrium and the adjacent parts of the cortex 

 dark or black about the ostiolum, otherwise the perifulcrium is uncoloured. 

 Pycnoconidia ellipsoidical, 25 4 in long, 1,2 1,8/t thick. 



React. Neither cortex nor medulla coloured by KOH or 

 Hymenium first blue, then dark vinous-red or almost black by J. 



f. nuda n. f. ad int. 

 Thallus isidiis destitutus. 



f. sciastra (Acn.) CROMB. 



Parmelia sciastra ACHARIUS Methodus Supplementum (1803) p. 49. 

 ACHARIUS Lich Univ. (1810) p. 471. 



Lichen fahlunensis /? sciastrus WAHLENBERG Flora Lapponica (1812) 

 p. 428. 



Physcia obscura var. sciastra NYLANDER Lich. Scand. (1861) p. 112. 

 NYLANDER Synopsis (1858-60) p. 428. WAINIO Adjumenta I (1881) 



P- 133- 



Physcia lithotea var. sciastra CROMBIE Brit. Lich. I (1894) p. 319 

 DALLA TORRE et SARNTHEIM Die Flechten von Tirol &c (1902) p. 168. 



