LECANORA.] LECANO-LECIDEEI. 375 



Subsp. 2. L. irrubescens Nyl. Flora, 1874, p. 318. Thallus 

 effuse, thin, scattered, tawny-yellow, at times subevanescent. Apo- 

 thecia subminute, biatorine, sessile, becoming convex and immargi- 

 nate, orange-red. Cromb. Grevillea, xix. p. 60. 



Differs in the characters given of the tballus and apothecia. The only 

 British specimen (fragmentary) is in lib. Salwey s. n. Lecidea picta TayL, 

 which Schierer (Enum. p. 149 ) referred to his var. 8. rubescens (non Ach.). 

 It is, however, identical with that of Anzi, Lich. min. rar. n. 135, upon 

 which Nylander founded this subspecies. 



Hab. On schistose rocks in a mountainous district. Distr. Seen only 

 very sparingly from N. Wales. B. M. : Near Barmouth, Merionethshire. 



31. L. crenulateUa Nyl. Flora, 1886, p. 461. Thallus subeffuse, 

 thin, unequal, rimose, citrine-coloured (K + purple). Apothecia 

 moderate, plane, zeorine, subconcolorous (K + purple), the thalline 

 margin when present finely crenulate; spores ellipsoid, polari-bilo- 

 cular (the loculi moderate), 0,016-20 mm. long, 0,008-9'mm. thick. 

 Cromb. Grevillea, xviii. p. 45. 



Well characterized by the double margin of the apothecia. It conies 

 near subsp. L. erythrella, but, as Nylander /. c. observes, is scarcely to 

 be subjoined under this. The thallus is little visible in the single speci- 

 men seen, but the apothecia are numerous and occasionally crowded. 



Hab. On quartzose rocks in a maritime district. Distr. Very local 

 and scarce in N.W. England (Arnside, Westmoreland). 



32. L. ochracea Nyl. in Cromb. Lich. Brit. (1870) p. 46. 

 Thallus determinate, thinnish, continuous or obsolctely rimoso- 

 areolate, ochrey-yellow (K + crimson). Apothecia small, sessile, 

 biatorine, at first concave, then plane, tawny-saffron or orange- 

 coloured (K -J- purple), the margin thin, paler: spores ellipsoid, 

 polari-bilocular, usually with longitudinal tube, 0,011-12 mm. long, 

 0,006-7 mm. thick.-^Leight. Lich. Fl. p. 218, ed. 3, p. 208. 

 Callopisma ochractum Mudd, Man. p. 138, t. 2. f. 43. Lecidea 

 ochracea Schaer. in Nat. Anz. 1819, p. 11. Lecidea icterica Tayl. 

 Lond. Journ. Bot. 1847, p. 150 (fide Leight. I. c.). 



Closely allied to L. aurantiaca, but distinguished among other cha- 

 racters by the constantly biatorine apothecia and the smaller spores. 

 The structure of the latter definitely separates it from L. tetrasticha Nyl., 

 to which externally it is almost similar and for which it is often 

 mistaken. It is usually limited by a more or less distinct whitish hypo- 

 thallus, and is always well fertile. 



Hab. On cahareous rocks in maritime and upland tracts. Distr. Very 

 local and rare in S.W. England, S. Wales, the S.W. Highlands of Scot- 

 laud, and ?S.W. Ireland. B. M.: Hope Cove, near Kingsbridge, S. 

 Devon; Giltar Point, Tenby, Pembrokeshire. Island of Lismore, 

 Argyleshire. 



33. L. ferniginea Xyl. Act. Soc. Linn. Bord. ser. 3, t, i. (1856) 

 p. 322. Thallus determinate or subeffuse, thinnish, areolato- or 



