444 LICHENACEI. [LECANOKA. 



Lecania erysihe Mudd, Man. p. ]4i pro parte, t. ii. f. 47. — Lichen 

 erysibe Ach. Prodr. (1798) p. 50. — L. erysihe /3. Rahenhorstii (Hepp), 

 Mudd, Man. /. c. is entirely confluent with the type. — Brit. Exs. : 

 Mudd, nos. 104, 10-5. 



A very vanable plant, the ditFerences in the thallus and apothecia of 

 ■which give rise to the forms, varieties, and subspecies that follosv. With 

 its usually biatoruid apotliecia it is at times not unlike Leeidea rubella 

 (Ehrh.j, of -which Acharius (Lich. Univ. p. 196) makes it a variety. 

 The apothecia are occasionally aggi'egate, and become darker in age. 

 The spermogoues, which are not very frequent in our specimens, have the 

 spermatia 0,015-18 mm. long, 0,0005 mm. thick. 



Hub. On rucks, very rarely on decorticated trunks of trees, in maritime 

 aud upland districts. — Distr. Here and there throughout Great lii-itaia ; 

 apparently rarer in the Channel Islands and Ireland. — B. M. : St. Aubin's 

 Fort, St. John's and St. Brelade's (lignicolous). Island of Jersey. Rot- 

 tingdean Cliffs, Sussex ; near Torquay, S. Devon : near Penzance, Corn- 

 ^vall ; Norton, Worcestershire ; near Aytou and Coatham, Cleveland, 

 Yorkshire ; St. Bees, Cumberland. Island of Lismore and Barcaldine, 

 Argyleshire ; Portlethen, Kincardineshire ; Craig Guie, Braemar, Aber- 

 deenshire. Lower Glanmire Road, co. Cork ; near Kilkee, co. Clai'e ; 

 CO. Down. 



Eorm cinereofusca, Crorab. Grevillea, xviii. (1890) p. 69. — 

 Thallus very thiu, greyish-brown. Apothecia minute, plane, at 

 length convex, dark-brown, slightly jH-uiiiose ; spores indistinctly 1- 

 septate, often 2-3-nucleolate. — Lecania eri/xibe var. c. cinercofKsca 

 Mudd, Man. (1861) p. 141, t. 2. f. 4S.—Bnt. Exs. : Mudd, n.* 106. 



Only a form with thinner thallus aud smaller subpruinose apothecia, 

 the pruina disappearing in age. Apparently it is coniiuent with the type 

 and results from the habitat. 



Hub. On rocks and walls in maritime and upland tracts. — Distr. Only 

 sparingly in S., W., and X. England. — B. M. : Hastings, Susses ; Crowle, 

 near Worcester ; near Ayton, Cleveland, Yorkshire. 



Var. p. sincerior Xyl. ilora, 1S76, p. 577. — Thallus subgranu- 

 late, areulato-rimose, pale-greyish or subochraceo-whitish. Apo- 

 thecia lecauoriue, pale-brown, the thalline margin persistent. — 

 Cromb, Grevillea, v. p. 108; Leight. Lich. Fl. ed. o, p. 219. 



Differs in the colour of the more granulate thallus and in the per- 

 sistently lecanorine apothecia. Nylander /. c. observes that it may rank 

 as a subspecies. 



Hab. On schistose aud arenaceous rocks and walls in maritime tracts. — 

 Di.<tr. Found sparingly in the Channel Islands, S. aud N. England, and 

 N.W. Ireland. — B. M. : La Coupe, Island of Jersey. Ha.?tings, Sussex ; 

 near Torpoint, S. Devou ; St. Bees, Cumberland ; North Tyne, North- 

 umberland. Lettermore, Connemara, co. Galway. 



Subsp. 1. L. albariella Xyl. Flora, 1^81, p. 454. — Thallus areo- 

 lato-diffract, whitish-creara-colourcd. Apothecia biatorine, smaller 

 submoderate, brown or brownith-black ; spores ovoid, 1-septate, 

 0,012-16 mm. long, 0,005-6 mm. thick ; hymeuial gelatine at length 



