LECANORA. 197 



lina, EaveneL Specimens on bark, referable here, are sent 



from Oregon (Lyall; Hall), in which the large apothecia become 



perfectly zeorine. A f. rosella, entirely analogous to L. pal- 



lescens, b, has, been found at Cumberland Gulf (Howgate exp.), 

 and might seem possibly the key to the also arctic L. tartarea v. 

 pertusarioides, Th. Fr. Lich. Arct. p. 100 ; but this author now 

 makes of his lichen a Pertusaria rhodoleuca, Lich. Scand. p. 



306. Rock specimens of this and the immediately preceding 



species are well-distinguishable ; and L. pallescens is a familiar 

 tree- and dead wood-lichen j but the present is not so satisfac- 

 torily determinable on bark. So far as observed by me the 



spores of the present are rather smaller than in L. pallescens ; 

 and this appears also to be noted by European lichenographers. 



* * * * AS pi cilia. Thallus now lobed (n. 33 ) or uniform. 

 Apothecia innate, more or less concave. Spores ellipsoid, simple. 

 Spermatia now needle - shaped, and now short -staff -shaped, 

 straight. 



34. L. melanaspis (Wahl.) Ach. ; thallus thick becoming 

 turgid, crustaceous-foliaceous ; ash-coloured and whitish ; pass- 

 ing at the centre into wart-like areoles, but extended at the cir- 

 cumference into linear, multifid, stellate-imbricate lobes ; apo- 

 thecia smallish to middling, closely sessile; the more or less 

 tumid, blackish-brown disk sub-marginate, and now pruinose ; 

 the thalline margin very entire. Spores ellipsoid and rounded, 



_j$ m ic. Parmelia, Fr. L. E. p. 122. Lecanora alphoplaca, 



Nyl. Scand. p. 152. 



Rocks. Greenland (Vahl), Th. Fries I. c. 1861. Bourbon 

 County, Kansas (on limestone), Hall. Yosemite Valley, Califor- 

 nia, Bolander. The specimens all belong to the f. alphoplaca } 



from which a Lapland form, not as yet known here (L. alpho- 

 placa, v. melanaspis, Nyl. 1. c. L. melanaspis, v. stellata, Th. 

 Fr. Scand. p. 229) differs in its smaller size, and thinner and 

 darker-coloured thallus. 



35. L. oculata (Dicks.) Ach. ; thallus cartilagineous-tartare- 

 ous, papillate-ramuliferous ; ashy- whitish ; apothecia smallish 

 to middling, sessile, flattish; disk black, sub-marginate; the 

 turgid, entire thalline margin often blackish, at length excluded. 



Spores ellipsoid, ^ mic. Ach. Syn. p. 148. Parmelia, Fr. 



L. E. p. 135. Lecanora, Nyl. Scand. p. 156. 



