292 PYRENOCAEPEI [VERRUCARIA 



Mudd's measiirements are not trustworthy ; those given for the 

 species are from specimens in the herbarium ; the variety differs in 

 the size and form of the spores. 



Hah. On maritime rocks.— Disir. Bare in S. and W. Ireland.— 

 B. M. Kerry ; Kilkee, Clare ; Leenane, Doughmagh, Connemara, 

 Galway. 



Var. minor A. L. Sm. — Thallus tartareous, very thin, greyish 

 or brownish. Perithecia smaller than in the species, numerous, 

 thinly scattered, hemispherical, shining black ; spores ellipsoid, 

 colourless, 0,014-17 mm, long, 0,006-7 mm. thick. 



Eesembling the species in habitat and type of thallus, but -nith 

 smaller perithecia and spores. 



Hab: On rocks near the sea. — Distr. S.W. coast of Wales ; 

 Manorbeer, Tenby, Pembrokeshire. 



37. V. limitata Krempelh. Lich. Fl. Bay. p. 241 (1861).— 

 Thallus tartareous-farinose, thin, glaucous-grey or brownish-grey, 

 continuous, irregularly traversed and limited by rather wide 

 brown or blackish lines. Perithecia minute, semi-immersed in the 

 thallus, hemispherical ; perithecia! wall dimidiate ; spores ellip- 

 soid, small, 0,012-14 mm. long, 0,006 mm. thick. — Shackleton 

 & Hebden in NaturaHst, 1892, p. 17. 



Differing in colour and form of the thaUus from other species with 

 limited thaJlus and from V. muralis, to which it is allied in the 

 character of the perithecia, by the much smaller spores. 



Sdb. On limestone and other rocks. — Distr. Bare in N. England. 

 — B. M. Hartlepool, Durham. 



38. V. muralis Ach. Meth. p. 115 (1803).— ThaUus effuse, 

 white or greyish, tartareous, pulverulent, thin, sometimes faintly 

 cracked-areolate, often evanescent. Perithecia black, hemi- 

 spherical, small, semi-immersed ; perithecial wall dimidiate, thick, 

 somewhat spreading at the base, with a thin brown wall below the 

 base ; spores ellipsoid, 0,017-25 mm. long, 0,010-12 mm. thick, 

 or slightly smaller. — Hook, in Sm. Engl. Fl. v. p. 154 pro parte? 

 Tayl. in Mackay Fl. Hib. ii. p. 91 pro parte? F. patula Leight. 

 Angioc. Lich. p. 61, t. 26, fig. 1 (1851). V. rupestris subsp. 

 muralis iSTyl. in Slaine et Loire Mem. Soc. Acad. iv. p. 32 

 (1858); Cromb. Lich. Brit. p. 114. Yai. muralis Mudd Man. 

 p. 292 (1861) ; Leight. Lich. Fl. p. 426 ; ed. 3, p. 456. 



The perithecia though slightly immersed in the thallus are super- 

 ficial on the substratum, and do not leave pits in the stone. Speci- 

 mens are occasionally found with smaller spores, 0,015 mm. long, 

 0,007 mm. thick. 



Hab. On brick walls, stones, naortar, &c. — Distr. Not uncommon 

 in the Channel Islands and throughout England, rare in Scotland and 

 Ireland. — B. M. Noirmont, Jersey ; Luccomb, I. of Wight ; Worth- 

 ing and Downs, Sussex ; Minchinhampton, Gloucestershire ; Much 

 Wenlock, Shropshire ; Norton and Malvern, Worcestershire ; Carlton 

 Bank and Ayton, Cleveland, Yorkshire ; Fenmanshiels, Berwickshire ; 

 near Cork ; BaUynahinch near Kylemore, Connemara, Galway. 



