LECANORA.] LECAXO-LECIDEEI. 401 



mm. long, 0,010-11 mm. thick; paraphysea not very discrete, 



ed. 3, p. 222. Brit. Exs. : Larb. Caesar, n. 78 ; Lich. Hb. n. 263. 



Closely resembles L. turfacea var. arcktea Ach., which does not occur 

 in our Islands, but differs in the character of the spores. Th thallus, 

 which elsewhere varies in thickness, is in our specimens thin and at timea 

 almost obliterated The apothecia are either scattered or crowded, the 

 young spores being 1-septate. 



Hab. On decayed turf and the ground, rarely on old excrements of 

 sheep, in maritime and upland districts. Distr. Local and sparino-ly in 

 the Channel Islands, E. England, and S. Wales. B. M. : La Move, Jersey; 

 Islands of Sark and Jethou. Thetford Warren, Norfolk. 



72. L. diplinthia Nyl. Ann. So. Nat. t. xix. (1863) p. 316. 

 Thallus indeterminate, thin or thiunish, unequal or subgranulose, 

 pale-greyish or pale-whitish (K , CaCl ). Apothecia small, plane, 

 brown (internally pale), the thalline margin entire ; spores ellipsoid, 

 4-locular (the two apical loculi simple, the two central each with 2 

 or sometimes 3 transverse cells), 0,023-34 mm. long, 0,012-16 mm. 

 thick ; paraphyses scarcely discrete. Leight. Lich. Fl. p. 230, ed. 3, 

 p. 222. 



An interesting plant, formerly known only corticolous from New 

 Granada, S. America. It is allied to the preceding species, but differs in 

 the character of the thallus, and in the smaller apothecia with their entire 

 thalline margin. The two British specimens seen are fragmentary, but 

 with numerous, crowded apothecia. 



Hab. On the ground in fissures of rocks in a maritime district. Distr. 

 Extremely local and scarce in one of the Channel Islands. B. M. : The 

 Eperquerie and D'lxcart Bay, Island of Sark. 



73. L. umbrinofusca Nyl. Flora, 1860, p. 389. Thallus deter- 

 minate, thin, subcontinuous or obsoletely rimulose, umbrine-brown 

 or umbrine-blackish (K ,CaCl ); hypothallus subplumoso-radi- 

 ating, leaden-coloured, usually limiting the thallus. Apothecia 

 lecideoid, minute, adnate, black, submarginate ; spores brown, 

 0,010-11 mm. long, 0,006-7 mm. thick; epithecium brown ; hypo- 

 thecium colourless. Cromb. Grevillea, x. p. 23. 



Looks quite a Lecidea, though the young apothecia are sublecanorine. 

 The spermogones ha\e not been seen, but it evidently belongs to this 

 section, near to L. yriseofusca Nyl., a Finland plant, to which it seems 

 closely related. It forms small, dark maculae upon the substratum, 

 which here and there become subconfluent. The single specimen seen is 

 well fertile. 



Hab. On siliceous stones in an upland tract. Distr. Found only very 

 sparingly in E. England. B. M. : Thetford Warren, Norfolk. 



74. L. sequata Xyl. Flora, 1884, p. 392. Thallus effuse, thin. 



