482 UCHENACEI. [LECAKORA. 



Form 2. denudata Cromb. Grevillea, xix. (1891) p. 58. 

 Apothecia moderate or small, naked, brownish-red or chestnut- 

 brown, the margin entire. 



The epruinose apothecia chiefly distinguish this form. Otherwise they 

 are in some specimens moderate and crowded (form conferta Cromb. 

 Journ. Bot. 1873, p. 134) ; while in others they are small and somewhat 

 scattered (form conspersa Fr., " apotheciis minoribus," Cromb. Grevillea, 

 i. p. 171). 



Hab. On calcareous and schistose rocks in mountainous districts. Distr. 

 Found only in N. England and the Central and N. Grampians, Scot- 

 land. B. M. : Near Dent, Yorkshire. Craig Tulloch, Blair Athole, 

 Perthshire ; Craig Guie, Braemar, Aberdeenshire. 



183. L. squamnlosa Nyl. Flora, 1872, p. 554. Thallus areolato- 

 squamulose, opaque, cervine, pale badious or badious-brown ; 

 squamules adnate, rounded at the margins, white beneath (K 

 (CaCl) ). Apothecia somewhat large, plane, reddish- or dark- 

 brown, the thalline margin usually depressed ; spores oblongo- 

 ellipsoid, 0,008-12 mm. long, 0,004-5 mm. thick; paraphyses not 

 discrete, occasionally jointed, brownish at the apices ; hymenial 

 gelatine deep blue with iodine. Cromb. Grevillea, xix. p. 58 ; 

 Leight. Lich. Fl. p. 183 pro parte, ed. 3, p. 169 pro parte. 

 Lichen squarnulosus Schrad. Crypt. Exs. (1797) n. 153. Lecanora 

 cervina (Pers.), Cromb. Lich. Brit. p. 56 pro minima parte. 

 Acarospora cervina a. squamulosa, Mudd, Man. p. 158 pro parte. 



Readily distinguished from the preceding species by the closely 

 appressed thallus, the contiguous differently coloured squamules, as also 

 by the thinner spores. It is not very variable, presenting only the form 

 that follows. The apothecia are at first immersed and then become 

 superficial. 



Hab. On calcareous rocks in mountainous districts. Distr. Apparently 

 very local and scarce in N. Wales, N.W. England, and on the Grampians, 

 Scotland. B. M. : Dolgelly, Merionethshire ; near Staveley, Kendal, 

 Westmoreland. Craig Tulloch, Blair Athole, Perthshire ; Craig Guie 

 and Morrone, Braemar, Aberdeenshire. 



Form albomarginata Cromb. Thalline squamules densely white- 

 pulverulent at the margins : otherwise as in the type. 



Analogous to form mosaica, Duf., Nyl., of L. castanea (Ram.), a plant 

 which does not occur in this country. 



Hab. On calcareous rocks in a subalpine district. Distr. Extremely 

 rare on one of the Central Grampians, Scotland. B. M. : Craig Tulloch, 

 Blair Athole, Perthshire. 



184. L. percaenoides, Nyl. ex Wedd. Bull. Soc. Bot. xvi. (1869) 

 p. 202. Thallus verrucoso-squamulose, thickish, chestnut-coloured, 

 white- or cassio-pruinose, the squamules convex, scattered or imbri- 

 cate (K ,CaCl ). Apothecia innate, concave, irregular, rounded 

 or difform, often crowded, reddish- or dark-brown, naked, the 

 thalline margin prominent, whitish ; spores ellipsoid, 0,004-6 mm. 



