90 



HKRNT LYNGE. M.-N. Kl. 



nient' encloses sever;il small convex areolae, Hue lo cracks in llic- thallus. 

 The lower side of (,. /cidCfir/ui varies from smooth to coarsely scabrous, 

 G. discolor is smooth (like (>. polyphylla). 



The anatomy f)f the two species ma}' he thus described: 



1. (.. Iciiicarpa. Upper cortex plectenchymatous, 40 — 70 \i., covered 

 with a rather thin, irregular, interrupted amorphous stratum, hyphae thick- 

 walled, densely contexted, their direction irregular, but more perpendicular 

 to the surface than parallel to it. Surface very uneven. 



Gonidia glomerate, either in undulate lines corresponding to the 

 surface, or often wanting under the concave parts of the surface, and only 

 developed in (under) the convex parts. 



Medulla a thin stratum of loosely contexted hyphae under the gonidia, 

 more like a rupture in the thallus. If the gonidia are absent, this medulla 

 is also absent, and the two cortices meet. Lower cortex less corneous 

 than die upper cortex, hyphae at the interior part ± parallel to the 

 surface, at the exterior part they turn more against the surface. Like the 

 upper cortex it is very uneven, almost papillose, the points of the papillae 

 are amorphous, uncoloured, at the base of the papillae the lower cortex 

 is yellowish-brown, its interior part is uncoloured. 



Pycnides immersed fn low papillae, depresso-globose, ca. 160 x 130 [x, 

 the whole perifulcrium black, pycnoconidia straight, cylindrical or elongato- 

 elliptic, 3 — 4 (5) [J- 



2. G. discolor. Upper side covered with a rather thick, amorphous, 

 uneven stratum of a very variable development. Cortex plectenclwmatous, 

 40 — 50 [J. thick, exterior part yellowish-brown; its h3'phae much more slender 

 and thin-walled than in G. Iciocarpa. Gonidia in a thick continuous stratum. 



Medulla well developed, of the usual structure, well set off from the 

 lower cortex. Lower cortex 40 — 80 [7., exterior part dark yellowish-brown, 

 hyphae rather thin-walled, otherwise as in C Iciocarpa. 



I have seen one sterile pycnide with entirely uncoloured perifulcrium. 



Both species are J -f- (i. e. not blue). 



The Second Norw. Arctic Expedition in the Fram brought home some 

 interesting Gyrophora (leg. Simmons), determined by Darbishire as G. 

 anthracina (= G. Iciocarpa)^. This is undoubtedly incorrect. A few speci- 

 mens of this \vuhracind' are very poorly developed, and a safe determi- 

 nation is hardly possible. The greater part is entirely G. discolor. The 

 Ellesmereland plants are i. p. larger than ours, the largest Norw. specimen 

 is 5 cm. in diam. (from Alten), the Ellesmereland plants are up to 9 cm. 

 The fuliginose colour of the lower face is more effuse and the margins 

 less involute than in our plants. 



The largest Ellesmereland specimen is very eroded and perforate, with 

 larger perforations than in G. crosa, it calls to mind the perforations of 



' I. c. No. 21. Lichens p. 24. 



