141 



NEW BRITISH LICHENS. 



Communicated by the Rev. J. M. Crombie, M.A., F.L.S. 



The following new species of .Lichens, recently discovered in 

 Great Britain, have been described by Dr. Nylander in the " Flora," 

 January, 1873, pp. 17-23:— 



1. Lecanora pxaepostexa. Nyl. — Thallus white, thin, sub-smooth, 

 areolato-rimose, Bnb-fimbriated, and darkly limited at the circum- 

 ference (K + yellow, and then cinnabarine-reddish) ; apothecia 

 blackish, opaqne, glanco-suffused or snbdenudate, moderate, the 

 thalline margine rngnlose or subcrenate, spores 8 nae, ellipsoid, 

 0,009-14 m.m. long, 0,005-6 m.m. thick ; paraphyses slender, 

 epithecinm yellowish ; hymeneal gelatine, and especially the thecae 

 bluish with iodine. 



On basalt rocks, in Jersey ( Larbalestier, 1872). Not unlike a 

 variety of Lecanora atrynea, Ach., but sufficiently distinct by the 

 smaller spores, the reaction of the thallus and the hymeneal gela- 

 tine, as also by the other characters as above. 



2. Lecanora coniopta. Nyl — Thallus greyish-brown, indeter- 

 minate, moderate, unequal, rimoso-diffract ; apothecia black, innate, 

 at first slightly margined, at length somewhat convex and immar- 

 ginate, white within ; spores 8 nae, brownish-black, ellipsoid, 1- 

 septate, 0,015-20 m.m. long, 0,008-10 m.m. thick, epithecium 

 brown, paraphyses moderate, subarticulated, hypothecium colour- 

 less ; hymeneal gelatine, bluish with iodine. 



On gneissic maritime rocks on the coast of Kincardineshire 

 (Crombie, August, 1872). Not unlike Lecidea coniops in external 

 appearance, but a true Lecanora. The spermogones are frequent, 

 black punctate, with arthrosterigmata, and slightly bacillar spermatia. 

 In the same locality was also gathered very sparingly, Lecanora 

 diphyodes. (Nyl., in " Flora," 1872, p. 353.) 



3. Lecidea leucophaeopsis. Nyl. — Thallus white, consisting of 

 small, rotnndato difformed squamules, which are adnate and de- 

 pressed in the centre, and either dispersed or contiguous (K + 

 yellow) ; apothecia brownish-black, opaque, convex, concolorous 

 within (the hymeneal stratum dark- greyish) ; spores 8 nae, colour- 

 less, fusiform, 3-5-septate, 0,024-34 m.m. long, 0,005-8 m.m. 

 thick ; paraphyses slender, not always very well discrete, epithe- 

 cium and hypothecium yellowish-brown ; hymeneal gelatine bluish, 

 and the thecae wine-red with iodine. 



Onquartzose stones of a wall on Ben Lawers. (Crombie, August, 

 1872.) The thallus of this species is not very uncommon here and 

 there on Ben Lawers, but it is very rarely seen in fruit. Between the 

 squamules there usually occur the pulvinuli of Sirosiphon saxicola, 

 Nag. Nylander observes that the present species recedes from all 

 known species ; but probably is to be systematically arranged near 

 to Lecidea sabuletorum. 



