LECANIA | LECANORACEX SDL 
Form metabolica A. L. Sm.—Thallus very thin. Apothecia 
minute, convex, dark-brown or nearly black, the margin excluded. 
—Lecanora metabolica Ach. Lich. Univ. p. 351 (1810). L. athroo- 
carpa var. metabolica Cromb. Lich. Brit. p. 53 (1870); Leight. 
Lich. Fl. p. 232; ed. 3, p. 224. LL. syringea £. metabolica Cromb. 
Monogr. i. p. 448 (1894). 
Distinguished by the smaller more scattered and darker apothecia. 
Hab. On trees, chiefly maple, in maritime districts.—Dvzstr. Very 
rare in the Channel Islands and 8. England.—B. M. Trinity, Jersey ; 
Brading, I. of Wight. 
‘19. L. dubitans A. L. Sm—Thallus a thin grey effuse 
rather irregular crust, sometimes almost obsolete (Kf+ yellowish, 
CaCl—). Apothecia minute, the disc pale- or dark-brown, the 
margin thin, soon evanescent ; paraphyses somewhat coherent, 
irregularly widening, septate and brownish upwards; spores 
oblong-fusiform or ellipsoid, usually curved, l-septate, 12-18 p» 
long, 4-6 p thick.—Lecidea dubitans Nyl. Lich. Scand. p. 207 
(1861) fide Th. Fr. Lich. Scand. p. 294.  Lecanora athroocarpa 
subsp. dimera Nyl. tom. cit. p. 169. L. dimera Nyl. ex Norrl. 
in Medd. Sallsk. Faun. & Fl. Fenn. i. p. 24 (1876) incl. var. 
dubitans ; Cromb. in Grevillea xviii. p. 70 (1890) & Monogr. i. 
p- 449. L. Sambuci subsp. dimera Wheld. & Wils. Lich. Perth. 
p. 40 (1915). 
Distinct from the preceding in the form of the spores. Crombie 
states that the epithecium gives a pale rose-coloured reaction with 
potash. I have failed to obtain this. 
Hab. On the smooth bark of trees in mountainous districts.— 
Distr. Rare in the Scottish Highlands.—B. M. Morrone, Braemar, 
Aberdeenshire. 
20. L. curvescens A. L. Sm.—Thallus of minute scattered or 
congregate grey roundish granules or minutely squamulose and 
dark-brown. Apothecia moderate in size, rather prominent, 
becoming expanded and thin and slightly convex, the disc dark 
reddish-brown, the margin lighter coloured, disappearing ; para- 
physes coherent, very slender,.more or less distinctly septate and 
variously widened upwards, pale yellowish-brown in the mass ; 
asci broadly clavate, 6—8-spored; spores obtusely fusiform, 
slightly curved, 3-septate, 30-34 » long, 4-6 p thick.— Pannaria 
curvescens Mudd Man. p. 125, t. 2, fig. 38 (1861). Lecanora 
curvescens Nyl. ex Carroll in Journ. Bot. iii. p. 288 (1865) 
emend. L. rhypariza f. curvescens Nyl. in Not. Sillsk. Faun. & 
Fl. Fenn. Foérh. n. ser. v. p. 135 (1866); Cromb. Lich. Brit. 
p- 53 & Monogr. i. p. 450; Leight. Lich. Fl. p. 214; ed. 3, 
p. 199. 
There is only one scanty specimen of this very rare lichen in the 
herbarium of the British Museum, but an examination of it has 
proved that the spores are distinctly 3-septate. The reaction with 
