Letidea.} LICHENES. 



53. L. icmadopJiila, ACH. Thallus filmy, with rotund granu- 

 lations, greenish-white, uneven, indeterminate ; apothecia sub- 

 sessile, flattish, flesh-coloured ; the disk at length wrinkled, and 

 the thin border flexuose. Ach. Lick. Un.p. 191. Enq. Bot. t. 

 372. 



On turf, under heath or furze ; not uncommon. The apothecia are 

 sometimes proliferous of others. 



54. L, marmorea, ACH. Thallus tartareous, very thin, 

 scarcely cracked, grey, indeterminate; apothecia urceolate ; 

 the disk of a salmon colour; the border very thick, raised, 

 subinflexed, crenulate, pale. Ach. L. Un. p. 192. Eng. Bot. t. 

 739. 



On limestone, common ; also on the bark of old elms, at Dunkerron. 

 The lamina proligera has a perithecium passing under it and rising up 

 into an elevated border. The variety on elms has its minute apothecia 

 almost entirely immersed ; in this, too, the lamina prolig era, dropping 

 out, leaves a whitish urceolate perithecium. 



55. L. lutea, HOOK. Thallus filmy, very thin, greyish, inde- 

 terminate, investing ; apothecia flat or concave ; the disk of a 

 pale yellow ; the border raised, whitish, waved. Hook. Eng. 

 Flor. v. 6, p. 185. Eng. Bot. t. 1263. Lee. melizcea, Ach. L, 

 Un.p. 194. 



On mosses, near Bantry, Miss Hutchins ; near Belfast, Mr. Tern," 

 pleton. In Askew Wood, County of Kerry. There is a perithecium 

 quite analogous to that of the preceding, out of which the lamina pro- 

 ligera occasionally drops. 



56. L. ulmicola, HOOK. Thallus leprous, coarsely mealy, 

 rather thin, whitish, indeterminate ; apothecia numerous, small, 

 somewhat crowded, brownish-tawney, at length convex, and 

 the border obliterated. Hook. Eng. Flor. v. 5, p. 185. Eng. 

 Bot. t. 1426. Lecidea luteo-alba, Ach. L. Un.p. 207. 



On limestone, at Dunkerron, County of Kerry. On calcareous 

 rocks the thallus is more truly mealy ; on elms, as in Mr. Harriman's 

 specimens from Durham, it is between filmy and tartareous. This 

 species is very nearly allied to Lee. rupestris, whose apothecia, how- 

 ever, are not so crowded, more convex, and immersed in the crust ; 

 besides their lamina proligera rests on a shallow, central, brownish- 

 tawny mass, while in L. ulmicola it rests on a whitish substance. 



57. L. aurantiaca, ACH. Thallus subtartareous, granulated, 

 uneven, black-edged, whitish, or whitish-lemon coloured ; apo- 

 thecia sessile, crowded ; the disk brownish-orange, at length 

 convex ; the border paler, entire. Ach. L. Un. p. 204. Lichen 

 salicinus, Eng. Bot. 1. 1305. 



On a wall, near Belfast, Mr. Templeton ; on rocks, near Bantry, 

 Miss Hutchins ; on willows and on sycamore at Derriquin, County 

 of Kerry. The black edge of the thallus is best observed on the spe- 

 cimens on Salix cinerea ; the thallus varies in thickness. The lamina 

 proligera is slightly tinged of the same colour as the disk : a thallodal 



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