122 LICHEN BS. [Lecidea. 



thick, smooth. Hook. Eng. Flor. v. 5, p. 178. Eng. Bot.t. 

 245. 



On siliceous and aluminous rocks ; common. This has the strongest 

 affinity to L. atro-alba ; from which it could scarcely be distinguished 

 on cursory observation but for the colour of the scales. Beneath a 

 thick black disk is a lamina proligera of a dusky brown, semi-trans- 

 parent, and striated, resting on a layer of black matter. 



25. L. silacea, Ach. Thallus thin, subtartareous, cracked, 

 uneven, wrinkled, almost warty, of a rusty red ; apothecia black, 

 sessile, somewhat convex ; the disk somewhat wrinkled ; the 

 border thin, waved. Ach. L. Un. p. 164. Eng. Bot. t. 1118. 



On sub-alpine rocks ; not rare. A spurious thallodal border to the 

 apothecia is very common ; the thallus is indeterminate ; under the 

 lens the disk appears studded with numerous black points, but these 

 are so far separated that the blackness of the surface is not continuous ; 

 the lamina proligera is nearly white, pellucid, striated, resting on a 

 small central portion of black matter. 



26. L. JEderi, Ach. Substratum of the thallus thin, black, 

 appearing in the interstices and at the border ; upper layer tar- 

 tareous, tessellated, of a dusky red, smooth ; apothecia black, 

 minute, rather concave, with a thick border. Ach. Syn. p. 22. 

 Eng. Bot. t. 1117. Lee. Dic.ksonii, Ach. L. Un. p. 165. 



On sub-alpine rocks ; not uncommon. Accompanies the preceding. 

 In both the structure of the apothecium is extremely similar, only in 

 the present the disk is flat or concave. Apothecia are often clustered 

 and confluent. 



27. L. scabrosa, Ach. Thallus tartareous, cracked, indeter- 

 minate, of a brownish-grey, with whitish elevations that dis- 

 charge buds greenish and powdery ; apothecia black, half im- 

 mersed, minute, often clustered. Ach. Meth. Lich. p. 48. Eng. 

 Bot. t. 1878. Ach. L. in. p. 180. 



On siliceous rocks ; not uncommon. The surface of the true thallus 

 is often covered and concealed beneath the buds, that appear as a 

 greenish powder. 



28. L. Jlavo-viresccns, Borrer? Thallus indeterminate, with 

 a pale brown, filmy, investing substratum ; scales very minute, 

 clustered in patches, of a lively yellowish-green ; apothecia 

 minute, black, on the substratum ; the disk plane or concave, 

 rough ; the border thick, entire, smooth. Borrer, 3ISS. accord- 

 ing to Hook. Eng. Flor. v. 5, p. 178 ? Lee. citrinella, Ach. L. Un. 

 p. 179? 



On mosses, at Bonane and Kilceanagh, County of Kerry. Doubts 

 arise as to the synonyms given above, since the authors above quoted 

 do not notice two distinct strata to the thallus, and since they denomi- 

 nate the apothecia to be globose. Our plant attracts the eye by its 

 colour, and the graniform aggregations of the scales into flatfish clus- 

 ters, each seldom exceeding a quarter of an inch in diameter. The 

 border of the apothecia is the mouth of a thick black cup, in whioh the 

 lamina proligera is contained, being a thick layer of pellucid, pale 



