CRYPTOGAMIA LICHENES. 7?> 



2. B. ciliaris, upper surface greenish-glaucous-grey ; the under 

 snow-white. HOOK. Scot. ii. 56. Lichen ciliaris, LIGHT F. Scot. 

 828. WITH. iv. 60. Eng. Bot. t. 1352. DILL. Muse. t. 20. f. 45. 



Hob. On rocks slightly covered with earth, and trunks of 

 trees. Lamberton-Moor. 



Frond somewhat depressed, dirty brown when dry, roughish, 

 branched, segments linear, pinnatifid, ciliate at the margins, 

 beneath channelled, wrinkled and white. 



3. B. tenella, greyish-white on both sides, somewhat furfura- 

 ceous. HOOK. Scot* ii. 56. Lichen tenellus, WITH. iv. 61. Eng. 

 Bot. t. 1351. L. ciliaris ft, LIGHTF. Scot. 828. DILL. Muse. t. 20. 

 f. 46. 



Hab On trees, shrubs, and stone-walls, very common. 



Frond depressed, circular, substellate, greyish-white; seg- 

 ments pinnatifid, narrow, ascending, ciliate, slightly dilated 

 and vaulted at the ends, or tubular. Apothecia scattered, 

 generally towards the centre, black, often covered with a 

 grey bloom, cupped, becoming plane or slightly convex, 

 the border white. SPRENGEL considers this a variety of 

 Parmella stellaris, an opinion which, whether correct or not, 

 shows how very closely the genera Borrera and Parmelia 

 are related. Their distinctive characters, indeed, appear 

 so trivial, that many authors discard the former genus, a cir- 

 cumstance which, in one view, and in one only, is to be re- 

 gretted, since the name was intended to commemorate a 

 very eminent botanist of our own country, a tribute of 

 respect from a foreigner to native worth and talent. 



45. PARMELIA. 



* Under surface paler coloured than the upper. 



1. P. olivacea, closely appressed, greenish-brown, shining ; lobes 

 plane, irregularly cut, rounded, tawny beneath ; " shields dark- 

 chestnut-olive, with an inflexed unequal margin." HOOK. Scot. ii. 

 52. Lichen olivaceus, LIGHTF. Scot. 819. WITH. iv. 37- Eng. Bot. 

 t. 2180. DILL. Muse. t. 24, f. 77, 78. 



Hab. On the smooth bark of trees, common, but without 

 fructification. 



