88 CRYPTOGAMIA LICHENES. 



contact with others, a black thread-like line marks the 

 bounds of each individual frond with great precision and 

 distinctness. Intermixed with Lee. luteola and Lecanora 

 nubfnsca, it will often run over, in a map-like manner, a 

 large portion of the trunk of the ash ; and every individual 

 plant, of whatever size, is bounded by this by no means 

 ideal line. 



5. L. sulphurea, crust asparagus-green, thick, uneven, rather 

 smooth, cracked when dry ; apothecia immersed, scarcely mar- 

 gined, blackish, mealy, small. HOOK. Scot. ii. 38. Lichen sulphu- 

 reus, WITH. iv. 12. Eng. Sot. t. 1186. 



Hob. On sandstone rocks at Hudshead, and on stone walls, 

 in subcircular patches, not uncommon. 



6. L. GEderij crust very thin, brownish- orange, even, cracked ; 

 apothecia immersed, dull black, cupped, with a thick tumid bor- 

 der HOOK. Scot. ii. 38. Lichen (Ederi, WITH. iv. 11. 



Hob. On loose stones of greywacke, in the west of Ber- 

 wickshire. 



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

 greyish-white areolse ; apothecia small, immersed, black, bordered, 

 convex in the centre HOOK. Scot. ii. 36. Lichen airo-albus, 

 WITH. iv. 5. 



Hab. On greywacke, with the preceding. 



8. L. atro-virens, crust very thin, spreading, sulphur-yellow, 

 cracked, areolar ; apothecia black, even with the crust, or slightly 

 concave, numerous, roundish or confluent HOOK. Scot. ii. 37. 

 Lichen geograpliicus, LIGHT r. Scot. 801. WITH. iv. 12. Eng. 

 Bot. t. 245. DILL. Muse. t. 18. f. 5. 



Hab. On rocks of greywacke, common. 



The crust of this pretty species spreads wide, and is divided 

 by black lines into unequal compartments, so as very ex- 

 actly to resemble a painted map, to which it has been often 

 compared. The old specific name ought to be restored. 



9. /,. conspurcata, crust spreading, greyish-white, cracked into 

 small irregular squares by black anastomosing lines ; apothecia 



