436 LTCHENACEI. [LECANORA. 



May readily be distinguished from the allied species by the colour of the 

 thallus and of the minute apothecia. These are usually crowded, at first 

 concave, becoming in age convex and iinmarginate. The spermogones, 

 rarely visible in our specimens, have the spermatia 0,011 mm. long. 



Hab. On old pales and the trunks of firs in lowland and upland situa- 

 tions. Distr. Only a few localities in Great Britain and Ireland; no 

 doubt often overlooked. B. M. : Near Millhill and Edgware, Middlesex ; 

 near Worcester ; Tugford Churchyard, Shropshire. Appin, Argyle- 

 ehire ; near Loch Tummel, Perthshire. Maam, Connemara, co. Gal way. 



Var. /3. ochrostoma Koerb. Par. Lich. Z. c. Apothecia sub- 

 biatorine, convex, yellowish.- or rusty-red, epruinose, immarginate. 

 Leight. Lich.. FL ed. 3, p. 174 (excl. loc. cit.) ; Cromb. Grevillea, 

 xviii. p. 69. 



Differs in the form and colour of the naked biatoroid apothecia. In 

 the few British specimens seen the thallus is almost obsolete. 



Hab. On old pales in wooded districts. Distr. Only sparingly in S. 

 and W. England. B. M.: New Forest, Hants; Braydon Forest, Wilt- 

 shire. 



Subsp. L. glaucella Nyl. ex Cromb. Grevillea, xix. (1891) p. 60. 

 Thallus glaucescent, at times subcvanescent. Apothecia sub- 

 livid, glauco-pruinose, the thalline margin entire, subpersistent ; 

 spores 0,009-13 mm. long, 0,003-4 mm. thick. Lecanora albella 

 var. glaucella Flot. Lich. Exs. n. 348 (1850). 



Characterized by the colour of the thallus and apothecia, which entitle 

 it to rank as a subspecies according to Nyl. in litt. The few British 

 specimens are well fertile. 



Hab. On the bark of pine trees in an upland district. Distr. As yet 

 only very sparingly in N.W.England. B. M. : Staveley, near Kendal, 

 Westmoreland. 



123. L. fugiens Nyl. Flora, 1873, p. 289. Thallus effuse, very 

 thin, granulate, scattered, glaucous or pale-whitish-yellow (K + yel- 

 low, CaCl + orange). Apothecia minute, sessile, whitish-isabelline, 

 the thalline margin entire or sometimes crenulate ; spores ellipsoid, 

 0,009-0,013 mm. long, 0,005-6 mm. thick ; paraphyses slender ; 

 hymenial gelatine bluish, then (especially the thecse) tawny wine- 

 coloured with iodine. Cromb. Grevillea, ii. p. 89 ; Leight. Lich. 

 Fl. ed. 3, p. 184. 



Near L. piniperda (ex Nyl. /. c.), but is well distinguished by the 

 characters given. In the two specimens seen the thallus is scattered 

 with the granules scarcely, or rarely, concrescent. The minute apothecia 

 are scattered, or here and there a few together. The spermogones have 

 the spermatia arcuate, 0,012-16 mm. long, 0,0005 mm. thick. 



Hab. On rocks in maritime districts. Distr. Extremely local and 

 scarce in the Channel Islands and N.W. Ireland. B. M. : Rozel, Island 

 of Jersey. Near Salrock, Connemara, co. Galway. 



