428 LICHENACEI. [LECANOBA. 



Closely related, like all the other plants of this subsection, to L. 

 umbrina, from which it differs in the characters given. In the British 

 specimen gathered the thallus is subgreenish and somewhat scattered, 

 with numerous, mostly subbiatorine apothecia,in which the paraph yses 

 are scarcely discrete. 



Hob. On granitic stones of a wall in a lowland district. Distr. Only 

 sparingly in N.E. Scotland; no doubt to be detected elsewhere. B. M.: 

 "Woodside, near Aberdeen. 



111. L. mammillifera Stirt. Trans. Glasgow Soc. Nat. 1875, 

 p. 85. Thallus minutely areolato-diffract, dark- or brownish-grey, 

 the areolae plane (X , CaCl ). Apothecia small, prominent, 

 convex, black or brownish-black, internally pale-greyish, the margin 

 (? thalline) obtuse, at length depressed ; spores ellipsoid, 0,008-010 

 mm. long, 0,007-0,0085 mm. thick ; paraphyses few, discrete, 

 thickish, brownish at the clavate apices ; hypothecium colourless ; 

 hymenial gelatine bluish, then tawny (especially the thecae) with 

 iodine. Leight. Lich. FJ. ed. 3, p. 201. 



I have seen no specimen of the plant, and as the author says nothing 

 as to its affinities or the character of the sperniogones, it may not belong 

 to this section. 



Hab. On rocks in a mountainous district Distr. Very local on one of 

 the Central Grampians, Scotland (Ben-y-gloe, Blair Athole, Perthshire). 



d. Thallus usually more or less yellowish. 



112. L. sulphurea Ach. Lich. Univ. (1810) p. 399. Thallus 

 thickish, rimoso-areolate, greenish-sulphur-coloured, the areolae 

 tumid, smooth (K + yellowish, CaCl ); hypothallus indistinct. 

 Apothecia moderate, at first innate, then protruded, biatorine, plane 

 or convex, difform, livid, olive- or livid-black, subpruinose, the thal- 

 line margin speedily excluded ; spores ellipsoid, 0,010-15 mm. long, 

 0,005-6 mm. thick ; paraphyses not discrete ; epithecium granulose, 

 brownish ; hymenial gelatine bluish and then sordid with iodine. 

 Mudd, Man. p. 152 ; Cromb. Lich. Brit. p. 52 ; Leight. Lich. Fl. 

 p. 198, ed. 3, p. 182. Lecidea sulphurea Sm. Eng. Fl. v. p. 181 ; 

 Gray, Nat. Arr. i. p. 470 ; Hook. Fl. Scot. ii. p. 38 ; Tayl. in Mack. 

 Fl. Hib. p. 127. Lichen sidphureus Hoffm. Enum. (1784) p. 32; 

 Dicks. Crypt, fasc. ii. p. 17 ; With. Arr. ed. 3, iv. p. 12 ; Eng. Bot. 

 t. 1186, upper fig. Brit. Exs.\ Leight. n. 114; Mudd, n. 121; 

 Larb. Lich. Hb. nos. 61, 92 ; Bohl. n. 117. 



Distinguished from the allied species chiefly by the colour of the thallus 

 and by the biatorine, usually immarginate apothecia. It frequently 

 spreads extensively over the substratum, the thallus varying somewhat 

 in thickness. The apothecia are numerous and crowded, becoming more 

 or less confluent. The spennogones are punctif orm, immersed, livid-black, 

 and often crowded. 



Hab. On rocks and walls in maritime, upland, rarely mountainous 

 districts. Distr. General and common in most parts of Great Britain 

 and Ireland ; rare in the Channel Islands. B. M. : Island of Sark. 



