36 ACOTYLEDONS. LICHENS. LeCldcct. 



2. ARTHONIA. 



Universal receptacle crustaceous, spreading, plane, adnate, uni- 

 form. Partial recept. sessile and subimmersed, roundish, but 

 varying in form, destitute of margin (black), covered with a 

 subcartilaginous membrane. 



1. A. aslroidea, crust membranaceous pale cinereous and glau- 

 cescent, apothecia flattened upon the crust plane angular sub- 

 stellate black. Ach. Syn. Lich.p. 6. Opegrapha astroidea* 

 E. B. t. 1847. 



HAB. On the smooth bark of trees, common, Hopk. 



3. SOLORINA. 



Universal receptacle foliaceous, coriaceous, lobed, free, beneath 

 having fibrous or woolly veins. Partial recept. adnate, 

 rounded, destitute of margin, covered by a coloured membrane. 



1. S. crocea 9 thallus greenish (brown when dry) lobed, beneath 

 veiny and of a fine saffron colour, apothecia "somewhat tumid 

 brown. Ach. Sun. Lich. p. 8. Lichen croceus, Light f. p. 856. 

 E.B. t. 498. 



HAB. Tops of the Highland mountains, not uncommon, especially in 



a micaceous soil, Ben Lomond, &c. 



Remarkable for the brilliant orange or saffron colour of the underside. 

 Habit of a Peltidea, near which it would much more naturally range. 



2. S. saccata, thallus lobed greyish green whiter and fibrous be- 

 neath, apothecia at length sunk into deep pits or hollows 

 brown. Ach. Syn. Lich.p. 8. Lichen saccatus, Lightf.p.855. 

 E. B. t. 288. 



HAB. Upon the earth in the chasms of the rocks that are damp and 

 shady, not unfrequent, especially in the Highlands, Lightf. 



B. Apothecia with a raised border or margin. 



4. LECIDEA. 



Universal receptacle various, crustaceous, spreading, adnate, uni- 

 form or foliaceous. Partial recept. scutelliform, sessile, sur- 

 rounded by a cartilaginous membrane, having a disk of a si- 

 milar nature with the raised border or margin. 



* Thallus crustaceous, uniform (Catillaria) . 

 t Apothecia constantly black, naked (not pruinose) . 



1. L.coracfwa, crust continued tessellated greyish black, apothecia 

 immersed between the areolae plane at length convex some- 

 what angular black of the same colour within. Ach. Syn. 

 Lich. p. \\. Lichen atratus, E. B. t. 2335. 



HAB. Granite rocks at the head of Loch Lee, in Glen Esk, Angus-shire, 

 rare, G. Don. 



2. L. atro-alba, crust spreading very thin cracked black with 

 swelling whitish scattered areolae, apothecia plane or slightly 

 convex often in the interstices black of the same colour within. 

 Ach. Syn. Lich. p. 11. 



