136 CLASS XXII. ORDER V. 



sile on the crust itself ; which are coloured and fi- 

 nally fall out, leaving pits at the summits of the 

 branches : frond crustaceous, leprous and tartar- 

 ous, cracked, rather indeterminate ; either papil- 

 lary only, or throwing up solid branches. Resem- 

 bles sphaerophoron ; but differs in having a base, 

 terminal globules, &c. 57. 2 — coralliiiusy (coral 

 lichen) warty-branched, tartarous, grey. 



3. Recefitacles orbicular^ ofien ; their border of the 

 colour of the frond^ surrounding a varioudy-co» 

 loured diak, 



Urceolaria. Shields or spangles cup-form, 

 variously coloured, sunk into the substance of the 

 crust, or of its fragments or warts : disk concave, 

 rarely becoming flattish by age, but never elevated 

 above the crust : proper border often scarcely man- 

 ifest, of the colour of the disk ; the accessory bor- 

 der sometimes formed of the crust, elevated like 

 a ring surrounding the disk of each shield : frond 

 crustaceous, tartarous, uniform, determinate, cheq- 

 uered *or cracked, rarely figured or lobate. Often 

 found on stones, &:c. and some species are insepar- 

 able from the stones on which they grow. 57. 2— 

 bryojihilla^ (pitcher-shield lichen) greyish with 

 glaucous-black shields. 



Parmelia. Shields superficial or elevated, 

 thick or sub-membranous, flattish, convex, or con- 

 cave, crowned with a free accessory border : frond 

 various, crustaceous, leafy, branched or laciniated, 

 cartilaginous, membranous or gelatinous. A vast 

 genus. One of its best characters is, that the 

 shield has no border of its own substance; but al- 

 ways has an accessary one of the substance of the 

 crust. 57. 2 — herbacea^ (shield lichen) bright 

 green with fulvous shields. 



