LECIDEA] LECIDEACEiE 57 



rounded, greyish-white (K + yellow, then orange-red) ; hypo- 

 thallus iDlack, at times limiting the thallus. Apothecia black, 

 or brownish-black, somewhat plane, becoming immarginate ; 

 hypothecium colourless ; paraphyses discrete, slender, the 

 epithecium umber-brown ; spores ellipsoid or oblong, 0,010-17 mm. 

 long ; 0,004-6 mm. thick ; hymenial gelatine and asci bluish 

 with iodine. The spermatia are arcuate as in L. leucophsea. 



Closely allied to the preceding, but differs in the subdeterminate 

 thallus, the more crowded areolae, the less prominent hypothallus, 

 ^nd in the thalline reaction. 



Hab. On rocks in upland districts. — B. M. Dolgelly, Merioneth. 



89. L. discolorella Nyl. in Flora Ix. p. 459 (1877).— 

 Thallus effuse, thin, whitish, areolate-rimose or scattered 

 (K 4- yellow, K (CaCl, -f red) ; hypothallus black. Apothecia 

 black, adnate or appressed, plane, becoming slightly convex and 

 immarginate ; hypothecium pale ; paraphyses discrete, reddish- 

 brown at the apices; spores ellipsoid, 0,012-16 mm. long^ 

 0,006-7 mm. thick. — Cromb. in Grevillea vii. p. 111. Lecanora 

 discolorella Leight. Lich. Fl. ; ed. 3, p. 176 (1879). 



Somewhat similar to L. leucopJicea, but the thallus is thin and 

 scanty and light in colour, and the thalline reaction is different. The 

 apothecia^ are at first sight like those of some species of Lecanora, 

 owing to the closely surrounding whitish thallus. The spermatia are 

 arcuate, about 0,020 mm. long and excessively slender. 



Hab, On rocks. — B. M. Near Penzance, Cornwall (the only 

 locality). 



90. L. viridiatra Sch^r. Enum. p. 108 (1850).— Thallus 

 greenish- or dull-yellow, indeterminate, thickish, areolate-diffract, 

 the areolae plane or convex, subcontiguous or scattered (Kf -f- 

 yellowish, CaCl — , medulla I — ) ; hypothallus black, distinct. 

 Apothecia small, appressed, plane and thinly margined, at length 

 somewhat convex and immarginate, blackish, hypothecium colour- 

 less ; paraphyses coherent, dark at the apices ; spores ellipsoid, 

 0,012-15 mm. long, 0,005-6 mm. thick ; hymenial gelatine bluish 

 then sordid, the asci wine-reddish, with iodine. — -L. luteoatra Nyl. 

 in Flora Ivi. p. 299 (1873) ; Cromb. in Journ. Bot. xiii. p. 141 

 (1875) ; Leight. Lich. Fl. ; ed. 3, p. 293. Biatora viridiatra 

 Stenh. Sched. Crit. xiv. p. 8 (1833). 



From its general appearance might readily be taken for a Lecanora 

 allied to L. polytropa. In our specimens, the areolae are rather 

 scattered, with the hypothallus very visible between them. The 

 apothecia, sparingly present in these, are at times 1-2 innate in each 

 areola. 



Hab. On quartzose boulders in a mountainous region. — B. M. 

 jNIorrone, Braemar, Aberdeenshire (the only locality). 



91. L. endomelaena Leight. in Trans. Linn. Soc. ser. 2, i. 

 p. 239 (1880). — Thallus pale-greyish-green, opaque, granular, the 



