236 LICHENS. 



ceous lichen. A greenish grey crust studded with pimples, 

 of the same colour, tipped with brown, is all the charm 

 it boasts. It is found in Norfolk, but we have been able 

 to procure no specimen. Thus, then, we complete our 

 present stock of lichens. We have collected diligently, 

 and though we have failed in procuring specimens of some 

 families, yet we have succeeded in far the greater propor- 

 tion. The seed of .these plants seems to be their most 

 important and reliable feature, which seeds are contained 

 in sacs, and the sacs lodged in a receptacle. Some sacs 

 contain but one seed, some two, and some many {fig. A.) 

 The receptacles are of various shapes and forms: goblet- 

 shaped, as in the goblet-lichens : linear, as in the writing- 

 lichens; wart-like, as in the wart-lichens, etc.; shields, as 

 in the Lecidea and Lecanora, etc. ; powdery warts, as in 

 the branch-lichens ; and tubercles, as in the cup-lichens. 

 The form of the frond, too, is a good mark of distinction : 

 crustaceous in the mushroom, goblet, writing, wart, 

 leprous, internal fruited, and shield-lichens ; the scaly 

 lichens, with fronds powdery within, and leafy towards 

 the edge, form a connecting link between the crusta- 

 ceous and frondose parties ; and the parmelias, lateral- 

 fruited, dotted, gelatinous, socket, circular, and buckler- 

 lichens are decidedly leafy in their habit. The last- 

 named verge towards the branched lichens, and the 

 ramilinas, usneas, hair, horned, coral, globe, and solid 

 belong to the leafy order. The cup form is restricted to 

 the one family of cup-lichens. 



The Eev. W. A. Leighton has worked out another 

 arrangement of lichens, dividing them by different 



