LEOANOHA.] LECANO-LECIDKEJ. 419 



Lecanora iiemtheUa Nyl. Flora, 1872, p. 305 ; Leiglil. Licli. V\. cd. :j, 

 p. 2U(j. 



Oripiiially rogardptl by Nylander as specifically distinct, tiiis is now 

 viewed by him only as a iorm characterized by the reaction of the 

 hymenial gelatine. 



Hah. On thurnsand trunks of trees in a maritime district — Distr. Very 

 rare in N.W. Ireland.— B. M. : Killery Bay and Ballynahinch, Cun- 

 nemara, co. Galway. 



Form 2. siibalbella Nyl. e.v Hue, llcv. Bot. 1887, p. 101. — 

 Spores 0,00iJ-ll mm. long, (•,005-7 mm. thick; hymenial gelatine 

 and the thecoe bluish, then darker with iodine. — Cromb. Grovillea, 

 xviii. p. GS. — Lecanora suhalbeJla Xyl. Flora, 1872, p. iJLio. — Lichen 

 rosellus Eng. Bot. t. 1G51 (apotheciis magis convexis). 



Only another form of L. aJbella, though more distinct than the pre- 

 ceding, ditltiring not merely in the reaction of the hymenial gelatine but 

 also in the slightly smaller spores and the slightly longer spermatia, which 

 Jide Nylander are 0,016-2:^ mm. long. 



Hab. On the trunks of trees in wooded maritime and upland tracts. — 

 Distr. Only sparingly in S. England. — B. M. : Netley Abbey, near Bartly 

 Lodge, and Bramble Hill, New Forest, Hants. 



99. L. angulosa Ach. Lich. Univ. (1810) p. 364 ; Nyl. Flora, 

 1872, p. 250. — Thallus determinate, thin, smooth, at length unequal 

 or rugoso-siibrimose, greyish- white (K-)- yellow, CaCl — ). Apo- 

 thecia small or submoderate, plane or slightly convex, crowded and 

 subangulose, pale-broAvn or sordid-pale, slightly coesio-pruinose 

 (epithecium CaCl + yellow); the thalline margin thin, subentire or 

 somewhat crenulate, at length subevanescent ; paraphyses slender, 

 sabdiscrete ; epithecium granulose ; spores 0,009-10 mm. long, 

 0,000-9 mm. thick ; hymenial gelatine persistently bluish with 

 iodine. — Leight. Lich. Fl. ed. 3, p. 205. — L. albeUa subsp. angulosa 

 Cromb. Lich. Brit. p. 51 ; var. /?. angulosa Mudd, Man, j). 148. 

 L. subfusca var. aiigidosa Leight. Lich. Fl. ed. 1, p. 204. Ljichen 

 angulosus Schreb. Spicil. (1771) p. 136. — Br'it. Evs.: Mudd, nos. 

 114, 115. 



Usually regarded as only a variety (or subspecies) of Z. albelln, this 

 essentially differs in the positive reaction of the epithecium with CaCl, 

 and in the black colour of the spermogones above. Among minor cha- 

 racters it also differs in the crowded angulose apothecia, especially in the 

 centre of the thallus, and in the rather larger spores. The spermatia are 

 shorter than in the preceding species, being (Jide Nyl. in litt.) 0,014-18 

 mm. long. 



Hab. On trunks of trees, rarely on old pales, in maritime and upland 

 districts. — Distr. Here and there in Great Britain and Ireland ; not seen 

 from the Channel Islands. — B. M. : Kpping Forest, Essex ; near Lewea 

 and Hastings, Sussex ; New Forest, Hants ; UUacombe, Bovey Tracey, 

 S. Devon ; Cirencester, Gloucestershire ; ClifFrigg and near Easby, Cleve- 

 land, Yorkshire ; Catterleen, Cumberland. Appin, Argyleshire ; Finlarig, 



2e 2 



