122 LECANO-LECIDEEI [bIATORINA 



numerous, spormatia oblong or oblong-ellipsoid, 0,004-5 mm. 

 long, 0,002 mm. thick. — Mudd Man. p. 179. Lecidea stjnothea 

 Ach. Syn. p. 2G (1814) pix) parte; Borr. in Elngl. Bot. 8uppl. 

 t. 2711 ; Hook, in Sm. Engl. Fl. p. 179. L. dcnigrata Nyl. in 

 Not. Siillsk. Faun, k Fl. Fenn. n. ser. v. p. 149 (186G) ; Cromb. 

 in Grevillea xxii. p. 10 <k Lich. Brit. p. 70 ; Leight. Lich. Fl. 

 p. 320 ; ed. 3, j). 364. L. parinsima Nyl. ex Cromb. in Journ. 

 Linn. Soc. xi. p. 484 (1871) & Journ. Bot. ix. 178 (1871); 

 Leight. Lich. Fl. ed. 3, p. 256. L. hemipoUella Nyl. in Flora 

 Iviii. p. 11 (1875); Leight. Lich. Fl. ed. 3, p. 339 (e descript.). 

 Biatora denigrata Fr. in Yet. Acad. Handl. 1822, p. 265 &, Lich. 

 Eur. p. 270. 



Exsicc. Johns, n. 373. 



Well characterized by the structure of the apothecia and the 

 appearance of the sperinogones. The thallus, which spreads ex- 

 tensively, is at times blackish, and occasionally but little visible, but 

 in that case the numerous and often conglomerate apothecia make 

 the plant sufhciently conspicuous. The spermogones are usually 

 abundant and are readily observed from the extrusion of the white 

 spermatia in the form of globules. 



Hah. On old palings, and occasionally on decorticated stumps of 

 trees in upland wooded districts. — Distr. Not unfrequent in England, 

 apparently rare in Scotland ; not seen from Ireland or the Channel 

 Islands. — B. M. Near Highbeach, Epping Forest, Essex ; Esher, 

 Surrey ; near Tunbridge Wells, Kent ; Albourne and Henfield, Sussex ; 

 New Forest, Hants ; near Bovey Tracy, Devon ; near Hendon and 

 Mill Hill, Middlesex ; Oaksey, Wilts ; near Elstree, Herts ; Chelms- 

 ford, Essex ; Twycross and Gopsall, Leicestershire ; Battenhall, near 

 Worcester ; near Barmouth, Merioneth ; Oswestr3^ and near Shrews- 

 bury, Shropshire ; near Ayton, Cleveland, Yorkshire ; Egremont, 

 Cumberland ; Finlarig, Killin, Perthshire. 



Var. semialbula A. L. Sm. — Thallus whitish or livid-whitish, 

 thin, slightly rimulose-areolate ; spores 2— 4-guttulate, septa dis- 

 cernible on treatment with potash. — Lecidea hemipoliella var. 

 semialbula Nyl. ex Stirton in Trans. Glasgow Soc. Nat. 1875, 

 p. 89 {fide Leight.); Leight. Lich. Fl. ed. 3, p. 339. Specimen 

 not seen. 



Hah. On decorticated wood. Collected by Dr. Stirton near Altna- 

 harra, Sutherland. 



Subsp. subnigrata A, L. Sm. — Thallus effuse, granulose- 

 areolate and furfuraceous, dark-greyish (K — , CaCl — ). Apo- 

 thecia small, convex, immarginate, usually conglomerate, brown- 

 ish- or reddish-black, colourless within ; epithecium sordid- 

 yellowish, paraphyses not discrete ; hypothecium colourless ; 

 spores ellipsoid, 0,009-11 mm. long, 0,004-5 mm. thick; hy- 

 menial gelatine bluish w^ith iodine. — Lecidea subnigrata Nyl. in 

 Flora xlix. p. 370 (1866); Leight. Ann. Mag. Nat. Hist, ser 3, 

 xix. p. 403 (1867) & Lich. Fl. p. 316; ed. 3, p. 331. Lecidea 

 denigrata subsp. subnigrata Cromb. Lich. Brit. p. 70. 



