290 PYRENOCARPEl | VERRDC ARIA 



mersed in tho areolae, the ostiole neaily plane or depressed, 

 scarcely visible ; perithecial wall pale-brownish-coloured ; spores 

 8 in the asciis, oblong-6)llipsoid, simple, then occasionally becoming 

 1-septate, 0,011-16 mm. long, 0,004-6 mm. thick.— Miidd Man. 

 p. 288 (excl. var. glaucina) ; Cromb. Lich. Brit. p. Ill ; Leight. 

 Lich. FI. p. 422; ed. 3, p. 453. Lichen fuscellm Turn, iu Trans. 

 Linn. Soc. vii. p. 90, t. 8, fig. 2 (1804); Engl. Bot. t. 1500. 

 Endocarpon fuscellum Ach. torn. cit. p. 675 ; Hook, in Sm. 

 Engl. Fl. V. p. 159 (excl. syn. E. tephroides var. polythecium) ; 

 Tayl. in Mackay Fl. Hib. ii. p. 101. Sayedia fuscella Fr. Lich. 

 Eur. p. 413 (1831) ; Leight. Angioc. Lich. p. 22, t. 7, fig. 2. 

 Exsicc. Mudd n, 276. 



Differs from the preceding in the brown thallus and in the lighter- 

 coloured perithecia. The spores sometimes become distinctly 2-celle(3, 

 suggesting affinity with the genus Thelidium, but in many specimens 

 they remain constantly simple, and on that account it has been 

 retained among the Verrucarice. 



Hah. On calcareous rocks, mortar of old walls, &c. — Distr. Rare 

 in the Channel Islands, S. and N. England, N. Wales, Central Scot- 

 land and S.W. Ireland. — B. M. Boulay Bay and Trinity, Jersey ; 

 Rustington, Sussex ; Eaton, Berks ; near Oswestry and Llanymynech, 

 Shropshire ; near Yarmouth ; near Stanhope, Durham ; Ireland. 



Thallus membranaceous, continuous, smooth. 



32. V. maculiformis Krempelh. in Flora xli. p. 303 (1858).— 

 Thallus very thin, olive-brown or blackish, forming small spots 

 on the stone, which are often confluent. Perithecia small, semi- 

 immersed, subglobose, becoming slightly depressed round the 

 minute ostiole, black and shining ; perithecial wall dimidiate ; 

 spores ellipsoid, 0,014-24 mm. long, 0,006-010 mm. thick. 



Distinguished by the thin olivaceous thallus and the numerous 

 shining black perithecia. 



Hah. On calcareous rocks, flints, &c. — Distr. Rare in S., Central and 

 N. England. — B. M. Near Cirencester, Gloucestershire ; Norton near 

 Worcester ; below Cader Idris, Merioneth ; Carlton and near Ayton, 

 Cleveland, Yorkshire ; Hartlepool, Durham. 



33. V. mutabilis Borr. ex Leight. Angioc. Lich. p. 55, t. 24, 

 tig. 3 (1851) (excl. syn.). — Thallus dark-brown, like an oily stain, 

 thin, filmy, membranaceous, continuous, smooth, subdeterminate 

 or effuse, often nearly evanescent. Perithecia brownish-black, 

 minute, scattered, prominent, hemispherical, sometimes polished 

 and shining, internally pale ; perithecial wall dimidiate ; spores 

 oblong, small, 0,008-012 mm. long, 0,005-7 mm. thick.— Mudd 

 Man. p. 293 (excl. syn.); Leight. Lich. Fl. p. 418; ed. 3, 

 p. 448. 



Has been confused with other forms on account of the variable 

 thallus. The thallus is thin and almost evanescent in the British 

 Museum specimen. 



Bah. On rocks, stones and pebbles. — B. M. Mayfield, Sussex. 



