134 CLASS XXII. ORDER V. 



zag, bordered : their disk flat or slightly concave, 

 naked or powdery, narrow, linear, rarely dilated : 

 their border is of their own substance, often very 

 narrow and scarcely perceptible, sometimes tumid, 

 elevated, and sometimes inflexed : frond crustace- 

 ous, uniform, thin, generally indeterminate, occa- 

 sionally leprous. 57. 2 — scrijita, (lettered lichcil) 

 clefts zigzag. 



Lecidea. Spangles sessile, witli a flattish or 

 convex disk : frond various, crustaceous ; uniform 

 and limited, scattered and indeterminate, leafy, 

 membran#tis, or stellate. 57. 2 — immersa^ (spangled 

 lichen) greenish white,''spangles black- 



Calicium. Puffs turbinate, lenticular, or near- 

 ly globose : generally elevated on a rigid simple 

 stalk of a different substance from the crust : frond 

 crustaceous, leprous or tartarous, uniform or scat- 

 tered, powdery and granulated or solid and che- 

 quered, or somewhat leafy and imbricated. This 

 genus was confounded with the fungi^ till distin- 

 guished by Persoon. 57. 2 — strigoneliwnj (fungus 

 lichen) crust none. 



2. Recep.tacles closed, at length ofiening. 



Gyrophora. Buttons superficial flattish : frond 

 leafy, peltate, between membranous and leafy. 57, 

 2— iyc//ca, (button lichen) brownish grey, peltate. 



Bathelium. Receptacles sessile, sub-globose, 

 opening by a deciduous lid, hollow, from 1 to 3 

 cells lined with seeds : frond crustaceous, inde- 

 terminate, uniform. 



Verrucaria. Tubercles elevated, discharging 

 their chained seeds by a terminal pore, or else they 

 fall out entire : frond thin crustaceous, uniform. 

 Very minute. 57. 2 — nitida, (mite lichen) pale 

 green, tubercles crowded. 



Endocarpon. Hollows hidden in the substance 



