358 iicHEKAOEi. [LECANOK.Y. 



structure of the spermogones. The thallus, which is of moderate size, is 

 ofteu thinly white-pruinose, especially towards the centre, but becomes 

 citrine when moistened. The apothecia, which are chiefly central, are in 

 age subbiatorine. The spermogones have the spermatia 6,003 mm. long, 

 0,001 mm. thick. 



Hab. On calcareous soil, shell-sand, and in the crevices of rocks in 

 maritime tracts. Distr. Local, thongh not uncommon where it occurs in 

 the Channel Islands, S. England, and S. Wales. B. M. : Quenvis, 

 Island of Jersey ; Island of Guernsey. Freshwater Bay, Isle of Wight ; 

 Newhaven and Rottingdean Cliffs, Sussex ; Bray Hill, St. jVlinver, 

 Cornwall ; Stackpole Court and Lydstep, Pembrokeshire. 



10. L. elegans Ach. Lich. Univ. (1810) p. 435. Thallus orbi- 

 cular, appressed, stellato-radiate, thickish, orange- or tawny-red ; 

 laciniae subdiscrete, multirid, convex, torulose (K-f- purplish). Apo- 

 thecia moderate, adnate, somewhat concave or nearly plane, conco- 

 lorous (K-f purplish), the thalline margin entire ; spores ellipsoid or 

 ovoid, 0,011-16 mm. long, 0,000-9 mm. thick. Cromb. Grevillea, 

 xviii. p. 44 ; Hook. Fl. Scot. ii. p. 50 pro parte. Placodium elegans 

 Mudd, Man. p. 131, t. ii. f. 41 ; Cromt). Lich. Brit. p. 45 ; Leight. 

 Lich. Fl. p. 178, ed. 3, p. 163. Squamaria ekt/ans Sm. Eng. Fl. 

 v. p. 195. Lichen elegans Link, Ann. Bot. i. (1794) p. 37. This 

 is the plant of most British authors only in so far as relates to the 

 diagnosis (evidently borrowed from Acharius) given by them, the 

 localities and habitats cited being chiefly erroneous. 



A beautiful lichen, somewhat resembling PJiyscia parietina var. ectanea, 

 but is of an Arctic or Alt-alpir.e type. From tbe other species of the 

 subgenus it is easily recognized by the thallus being distinctly corticate 

 on both sides. Elsewhere in Europe it is rather variable, presenting 

 several well-marked varieties, of which only one has been met with in 

 this country. The few British specimens seen are rarely fertile, the 

 spermogones also being rare, with spermatia 0,C03-4 mm. long, 0,(01 

 mm. thick. 



Hab. On granitic rocks in alpine situations. Distr. Only very spar- 

 ingly among the N. Grampians, Scotland. B. M. : Lochnagar and 

 Cairngorm, Braemar, Aberdeenshire. 



Yar. /3. tenuis Ach. Syn. (1815) p. 183.- Thallus small, thin ; 

 laciniao narrow, discrete. Apothecia small. Cromb. Journ. Bot. 

 1885, p. 195. Lichen elegans ft. tenuis Wahlenb. Fl. Lapp. (1812) 

 p. 417. Lecanora eleyans form minor Cromb. Journ. Linn. Soc. 

 Bot. xvii. p. 571. Placcdium eleyans ft. discreta (Schser.), Mudd, 

 Man. p. 131. Lichenoides tenuissimum, scutellis exiguis minlatis 

 Dill. Muse. 175, t. 24. f. 68. 



Differs in the much smaller thallus, the narrower subfiliform discrete 

 radii, and the smaller apothecia. In most Biitish specimens the thallus is 

 minute, with the ladii somewhat scattered, and very sparingly fertile. 



Hab. On calcareous rocks in snbalpine situations. Dittr. Very local 

 and scarce in S. Wales, N. England, and among the N. Grampians, 

 Scotland. B. M. : \Vhimbold Rocks, near New Radnor, Radnorshire: 

 East Allendnle, Northumberland. Craig Guie, Bvuemar, Aberdccnshirw. 



