292 PYRENOCARPKI [VKRRUCARIA 



Miidd's mcasiiromcnts arc 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. Rare in S. and W. Ireland. — 

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

 Gal way. 



Var. minor A. L. Sm. — Thallus tarfcareous, 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. 



Resembling the species in habitat and type of thallus, but with 

 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 ; perithecial wall dimidiate ; spores ellip- 

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

 & Hebden in Naturalist, 1892, p. 17. 



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

 limited thallus and from V. 7nuralis, to which it is allied in the 

 character of the perithecia, by the much smaller spores. 



Hab. On limestone and other rocks. — Distr. Rare in N. England, 

 — B. M. Hartlepool, Durham. 



38. V. muralis Ach. Meth. p. 115 (1803).— Thallus 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. 9 1 pro parte ? V. patula Leight. 

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

 muralis Nyl. in Maine et Loire Mem. Soc. Acad. iv. p. 32 

 (1858) ; Cromb. Lich. Brit. p. 114. Var. 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, mortar, &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 ; Penmanshiels, Berwickshire ; 

 near Cork ; Ballynahinch near Kylemore, Connemara, Galway. 



