364 LICUENACEI. [LECAXOKA. 



effigurate at the circumference, bright-yellow or orange-red (K-f 

 purplish). Apothecia minute, numerous, plane or convex, con- 

 colorous (K + purple), thalline margin entire; spores 0,010-14 mm. 

 long, 0,005-6 mm. thick. Cromb. Grevillea, xviii. p. 45. Placodium 

 murorum ft. lobulatum Mudd, Man. p. 132 ; Cromb. Lich. Brit. p. 45. 

 Var. obliteratum (Pers.) Leight. Lich. Fl. p. 176, ed. 3, p. 161. 

 Brit. Exs. : Leight. n. 268 ; Cromb. n. 156 ; Larb. Ceesar. n. 74 ; 

 Lich. Kb. n. 295. 



Distinguished from all the preceding species by the less developed and 

 almost non-radiate thallus. In a young state it is orbicular and slightly 

 effigurate, but becomes indeterminate (often spreading extensively), with 

 the peripheral radii indistinct. When the colour is more miniate, it is 

 Lichen obliterates Pers. Ust. Ann. Bot. ii. p. 15 (miniatus auctorum pro 

 parte). The apothecia are very numerous and crowded, usually almost 

 obliterating the thallus, becoming at length convex and iinmarginate. 

 The spernaogones have the spermatia oblong, 0,002-3 mm. long, 0,0005-7 

 mm. thick. 



Hab. On rocks in maritime districts. Dvstr. Here and there through- 

 out Great Britain, Ireland, and the Channel Islands ; very abundant on 

 the coast of Kincardineshire. B. M. : Rozel, Island of Jersey ; West 

 Coast of Guernsey ; Island of Alderney. Ilsham, Torquay, Devonshire ; 

 St. Maws, Cornwall; North Cliff, Tenby, Pembrokeshire ; Southerndown, 

 Glamorganshire; Barrnouth, Merionethshire; Island of Anglesea; 

 Douglas, Isle of Man ; St. Bees, Cumberland ; Arnbarrow, Westmore- 

 land. Appin, Argyleshire ; Portlethen, Kincardineshire ; Peterhead, 

 Aberdeenshire ; Applecross, Ross-shire. Upper Lake, Killaruey, co. 

 Kerry ; Ardglass, co. Down. 



16. L. scopularis Nyl. Flora, 1883, p. 105. Thallus orbicular, 

 somewhat small, firm, naked, radiately divided at the circumference, 

 verrucoso-areolate in the centre, vitelline ; radii narrow, contiguous, 

 convex (K + purplish). Apothecia small, numerous, plane, con- 

 colorous (K + purple), the thalline margin entire ; spores 0,009-0,017 

 mm. long, 0,005-7 mm. thick. Cromb. Journ. Bot. 1885, p. 195. 



Approaches L. lobulata, but differs especially in the distinctly placodioid 

 thallus. In the single fertile British specimen seen, the apothecia are 

 numerous, with the thalline margin persistent. The spermogones are 

 rarely present, with spermatia oblong, about 0,0025 mm. long, 0,0005 

 mm. thick. 



Hab. On schistose rocks in a maritime district. Distr. Found only 

 very sparingly in N.E. Scotland. B. M. : Portlethen, Kincardineshire. 



17. L. miniatula Nyl. Flora, 1883, p. 98. Thallus small, 

 orbicular, plane, closely adnate, thinly rimoso-areolate, slightly 

 subeffigurate at the circumference, deep tawny-vermilion-coloured 

 (K -f- purplish). Apothecia minute, ooncolorous (K -f purple), the 

 thalline margin entire; spores 0,007-10 mm. long, 0,004-5 mm. 

 thick. Cromb. Journ. Bot. L885, p. 195. 



Subsimilar to L. lobulata (obliterate), but differs in the subeffigurate 

 thallus, the smaller apothecia, and more especially in the smaller spores. 

 It probablv, however, descends from subsp. L. teyularis, of which it 



