PLACODIUM | PHYSIACEX 223 
Though made a species by Nylander, it is very closely related 
to var. festivum. The spores of our specimens are very distinctly 
polarilocular and measure about 15, long and 7u thick. As in the 
variety the thallus gives little or no reaction with potash. 
Hab. On schistose rocks in an upland situation.—Bb. M. Near 
Kendal, Westmoreland. 
37. Pl. cerinellum A. L. Sm.—Thallus thin, sordid-greyish, 
scarcely visible (K + yellowish). Apothecia minute, subbiatorine, 
bright-yellow (K + purplish); spores 8, 12 or 16 in the ascus, 
ellipsoid, polarilocular, small, 9-12 p long, 5-6 p thick.— 
Lecanora cerinella Nyl. in Bull. Soc. Bot. Fr. xiii. p. 370 (1866) 
& in Bull. Soc. Linn. Norm. sér. 2, vi. p. 260 (1872); Cromb. 
in Journ. Bot. xx. p. 273 (1882) & Monogr. i. p. 382. Specimen 
not seen. 
Described by Nylander as resembling a minute Pl. cerinum, but 
it differs in the number of spores inthe ascus. It has been frequently 
recorded on the Continent. 
On branches of trees in lowland districts.—Distr. E. England, 
near Cambridge. 
38. Pl. luteoalbum Hepp Flecht. Eur. n. 202 (1853).—Thallus 
effuse, thin, furfuraceous, greyish-white, sometimes evanescent 
(K +). Apothecia generally numerous and crowded, small, at 
first innate, then superficial and plane, with a thin paler proper 
margin, becoming convex, deep orange-yellow (K + crimson) ; 
hymenium rather narrow; paraphyses slender, septate and rather 
swollen at the tips, sometimes distinctly capitate; spores ellipsoid, 
small, the polar loculi very distinct, but the median septum thin, 
9-11 p long, 4-5 p thick.—Lichen luteoalbus Turn. in Trans. 
Linn. Soc. vii. p. 92, t. 8, fig. 3 (1804); Engl. Bot. +. 1426. 
Patellaria ulmicola DC. Fl. Fr. i. p. 358 (1805). Lecidea 
luteoalba Ach. Lich. Univ. p. 207 (1810); S. F. Gray Nat. Arr. 
i. p. 475; Hook. Fl. Scot. i. p. 40. L. ulmicola Borr. ex Hook. 
in Sm. Engi. Fl. v. p. 185 (1833). Callopisma luteoalbum Massal. 
Monogr. Lich. Blast. p. 80 (1853); Mudd Man. p. 136. Lecanora 
pyracea var. ulmicola Leight. Lich. Fl. p. 222 (1871); ed. 3, 
p- 211. JL. luteoalba Nyl. ex Lamy in Bull. Soc. Bot. Fr. xxv. 
p. 398 (1878); Cromb. Monogr. i. p. 385. 
Ezxsicc. Bohl. n. 76; Cromb. n. 61; Larb. Lich. Hb. n. 168 
& Cantab. n. 19; Leight. n. 84; Mudd n. 98. 
Often associated with Pl. pyracea, but differing in the deeper 
colour of the apothecia and in the spore characters. Gonidia are 
present in a broad band below the hypothecium, but not in the 
margin. 
Hab. On trees, chiefly elm, and on old wood.—Distr. Fairly 
general throughout the British Isles—b. M. Near Ventnor and near 
Shanklin, I. of Wight; Lewes, Glynde, Washington, Danny Park and 
Woodmancote, Sussex ; Eynsford, Kent; near Mill Hill, Middlesex ; 
Elstree, Herts; Stowe Park, Bucks; Windsor Great Park, Berks; 
Epping Forest, Stansted Mountfitchet and Great Waltham, Essex ; 
