144 LICHENES. [Parmelia. 



in our plant central ; 10, the constancy of the perforations of the 

 disks of the apothecia, which in our plant almost never occurs, at least 

 not oftener than what may be observed in P. perlata, P. omphalodes, 

 or P. saxatilis. As the Lichen proboscideus of Linnaeus is a Gyro- 

 phora, I have ventured to continue the trivial name of Allioni to our 

 Parmelia, all chance of confusion being removed by the well marked 

 differences of these genera. 



10. P. horrescens. Thallus orbicular, substellate, greenish- 

 grey when moist; greyish-white when tlry, shining; lobes small 

 incised, with circular sinuses, subcrenate ; the tops deflexed, be- 

 neath light brown, with black fibres ; the buds brown on whitish 

 solid podetia, crowded towards the centre, and expanding into 

 new individuals; apothecia unknown. 



On the perpendicular faces of siliceous rocks, facing the South, on 

 Dunkerron mountain, County of Kerry. The patches seldom exceed 

 two inches in diameter, and are usually much less ; the central region 

 covered with brown buds, extends to very near the circumference, 

 where the short small lobes of the shining greyish white thallus are 

 visible as a narrow rim. It has a strong affinity to P. saxatilis, from 

 which it is principally distinguished by the less linear lobes, which are 

 never pitted or reticulated, but shining and deflexed at the tops ; and 

 so in characters would approach P. laevigata but for the decidedly dif- 

 ferent nature of the buds. 



11. P columnaris. Thallus substellate, white, lobes minutely 

 subpruinose, convex, multifid, covered about the centre with 

 crowded erect, solid, white podetia, bearing slightly brown 

 buds; apothecia unknown. 



On wet rocks on mosses and Jungermannice, Dunkerron. To the 

 naked eye little more is observable than a patch of the slightly brown, 

 coarse granules, fringed around by a very narrow strip oi milk-white 

 laciniated frond. The lens detects a close columnar aggregation of the 

 buds : these breaking off exhibit a greenish-grey fracture. Closely 

 allied to P. aleurites, Ach. but I suppose distinct ; 1, by the milk 

 white thallus ; 2, by the pruinose not shining, rather convex, not con- 

 cave lacinice of the frond ; 3, by the pale brown (not dark) tops or 

 buds on the larger, more fastigiate podetia. 



12. P. saxatilis, Ach. Thallus substellated, glaucous-grey ; 

 the lobes retuse incised, reticulated with elevated ridges, bear- 

 ing brown buds on whitish, short, solid podetia black and fibrous 

 beneath ; apothecia central, the disk brown, the border inflexed, 

 rough with buds. Ach. L. Un. p. 469. Eng. Bot. t. 603. (not 

 good.) 



On rocks, stones, and trees ; very common. This varies much in 

 the size of the thallus and in the breadth of its segments. Apothecia 

 though common, yet they are usually few in number ; when old often 

 very large and flexuose, and covered with buds : the colour of the 

 disk, sometimes, nearly vermillion. 



13. P. fuifuracea, Ach. Thallus branched, greyish, the 

 segments diffuse, linear, attenuated, channelled beneath, farina- 

 ceous, with pale olive buds on greyish solid cylindrical podetia. 



