136 LICHENES, [Lecanora. 



mortar, at Templeogue, near Dublin, with the thai 1 us in scattered 

 granules ; the apothecia numerous, crowded, hence subangular, their 

 disk concave, light brown, with a dense white pruina, their border even 

 in the youngest and minutest, waved and erenulate. 7, crustless, apo- 

 thecia very minute, dispersed ; their disk olive, pruinose ; on siliceous 

 rocks at Derriquin, County of Kerry ; the same, I suppose it is, that 

 occurs on limestone on the seashore, often occupying the crust of 

 Thelotrema exanthematicum, and looking like the minute apothecia of 

 Lecanora chloroleuca, Ach. In all the different varieties dissection 

 shows beneath a disk more or less intensely coloured, brownish, a 

 lamina proligera of considerable thickness, of a pale waxy hue, semi- 

 pellucid and striated. 



* * Apothecia red, yellow, or brown, (never black.) 



10. L. ventosa, ACH. Thallus tartareous, thick, rimoso-areo- 

 late, of a yellowish-ash colour, scarcely determinate ; the areola; 

 convex, plaited, and warty ; apothecia rather large, somewhat 

 immersed, irregularly roundish; the disk flat or slightly tumid, 

 brownish-red ; border waved, narrow, entire. Ach. L. Un. p. 

 399. Eng. Bot. t. 906. 



On granite near Dublin ; Dr. Whitley Stokes. Slieve Croob, Mr. 

 Templeton. In old dried specimens the thallus sometimes becomes 

 quite brownish, and loses all yellowish hue. The areolce are often 

 confluent, always convex. The young unformed apothecia rise with a 

 tumid border from the crust. The disk and lamina proligera are of the 

 same colour, that is, a reddish-brown, the latter forms but a thin layer 

 over much white cortical matter, and is semipellucid and striated. 



11. L. Htzmatomma, ACH, Thallus leproso-tartareous, pow- 

 dery, whitish or pale sulphur coloured, subdeterminate ; apo- 

 thecia immersed ; the disk scarlet or brownish-red, at length 

 convex ; the border powdery, merging in the thallus. Ach. L. 

 Un. p. 388. Eng. Bot. t. 486 and t. 223. 



On rocks near Belfast, Mr. Templeton ; on shaded rocks near Dun- 

 kerron, County of Kerry. The thallus becomes thinner and white 

 towards the border ; but when two thalli of this species meet (and 

 sometimes independently of this,) there is a narrow black edge 

 visible. The dissection of the apothecia exhibits appearances quite 

 similar to what is observed in Lecanora ventosa. I find the thallus to 

 vary in thickness, and sometimes to be completely tartareous and 

 areolate ; to vary too as to the degree in which the surface is powdery. 

 I must confess, to me, the distinctions between this and the preceding 

 are very unsatisfactory. 



12. L. cerina, ACH. Thallus membranaceous, very thin, 

 slightly granulated, indeterminate, greyish-white ; apothecia 

 scattered, sessile ; the disk flat or concave, at length scarcely 

 convex, of a wax-yellow ; the border inflexed, with a white 

 pruina, at length turning black. Ach. L. Un. p. 390. Eng. 

 Bot. t. 627. 



On trees, near Dublin, Mr. Templeton ; in Kerry, not uncommon. 

 On dissection th lamina proligera fc seen to lie, in a lenticular form, on 



