372 LICHENACEI. [LECANORA. 



and upland tracts. Distr. General and common in the Channel Islands, 

 and throughout Great Britain ; apparently rare in W. Ireland. B. M. : 

 Islands of Jersey and Sark. Norwich, Norfolk ; Wimpole Park, Cam- 

 bridgeshire ; Bonchurch and St. Lawrence, Isle of Wight ; Torquay, 

 Devonshire ; Withiel, Cornwall ; Cirencester, Gloucestershire ; near 

 Windsor, Berkshire ; Oswestry, and near Shrewsbury, Shropshire ; near 

 Monmouth; Island of Anglesea ; near Ayton, Cleveland, Yorkshire; 

 Brougham Castle, Westmoreland ; Hexham, Northumberland ; Lam- 

 plugh, Cumberland. Near Edinburgh ; Gourock, Renfrewshire ; Cupar, 

 Fifeshire ; King's Park, Stirling ; near Doune, Perthshire ; Wills Braes, 

 Forfarshire ; Nigg, Kincardineshire ; near Aberdeen. Dunkerron, co. 

 Kerry ; near Kylemore, Connemara, co. Galway. 



Form depauperata Cromb. Grevillea, xviii. (1889) p. 45. Thal- 

 lus effuse, little developed, the granules minute, very much scattered. 

 Apothecia small ; otherwise as in the type. Brit. Exs. : Larb. Lich. 

 Hb. n. 128. 



The thallus is but sparingly visible, and at times inspersed here and 

 there over what seems to be Pannularia nigra, upon which the fructifi- 

 cation then looks as if parasitic. 



Hob. On granitic rocks in maritime tracts. Distr. Seen only from the 

 Channel Islands and N.W. Ireland. B. M. : Island of Alderney. Kyle- 

 more, Connemara, co. Galway. 



28. L. flavocitrina Nyl. Flora, 1886, p. 461. Thallus indeter- 

 minate, thinnisb, minutely squamulose, citrine-yellow ; squamules 

 appressed, more or less citrino-pulverulent (K + purplish). Apo- 

 thecia small, somewhat concave or plane, biatoroid, orange-yellow 

 (K + purple), the margin entire, paler; spores ellipsoid, polari- 

 bilocular, 0,007-10 mm. long, 0,006 mm. thick. Cromb. Grevillea, 

 xviii. p. 45. 



Subsimilar to the preceding species, but differs in the character of the 

 thallus and in the biatoroid apothecia. The squamules are either 

 entirely citrino-pulverulent, or only so at the margins. The specimen 

 seen is well fertile, with occasional traces of a thalline margin to the 

 young apothecia. 



Hob. On schistose walls in an upland situation. Distr. Only in N.W. 

 England (Staveley, near Kendal, Westmoreland). 



29. L. incrustans Ach. Lich. Univ. (1810) p. 405 ; Nyl. Flora, 

 1883, p. 106. Thallus effuse, crustaceous, verrucose, more or less 

 diffract, pale-yellow, subpulverulent (K -f- purplish). Apothecia 

 small, plane or slightly convex, deeper yellow, pruinose (K + purplish), 

 the thalline margin thickish, entire ; spores ellipsoid, polari-bilo- 

 cular, 0,008-13 mm. long, 0,004-8 mm. thick. Cromb. Grevillea, 

 xviii. p. 45. 



A plant seldom rightly discriminated. It is allied to L. citrina, from 

 which it may be recognized by the paler thallus and apothecia. In the 

 only British specimen seen, the apothecia are numerous with the thalline 

 margin persistent. The spermogones have the spermatia oblong or 

 subellipsoid, 0,020-25 mm. long, 0,005-7 mm. thick. 



