LICHENS. 223 



and shield-shaped. The fringed Borrera (B. ciliaris, Plate 

 XV., fig. 11) is frequently found, and we have specimens 

 from various localities, but the largest fronds and deepest 

 fringe is on plants which we gathered off some stately 

 elms in the glebe fields at Brixton Deverill, in "Wiltshire. 

 The thallus is greenish grey, the green tint predominating 

 when moist, and the grey when dry, a brown tinge 

 mingles with the grey on the under side, and the fringe 

 bears the same tint. The chestnut apothecise are borne 

 in abundance, and the curled lobes laid one over another, 

 tier beyond tier, spreading into patches half a foot wide, 

 are highly decorative to the Elm Bark. The Dwarf 

 Borrera (B. tenalla, Plate XV, Jig. 12) is a frequent 

 parasite on thorn bushes.- Its little fringed fronds, grey, 

 and lined like those of its big brother, were encircling 

 the ragged elbows of the Blackthorn bushes on the 

 Chough rock, overlooking the Cornish sea ; they clothed 

 the Hawthorns in the Goblin Combe, Somersetshire, and 

 endowed the thorny thickets on the Wiltshire Downs 

 with hoary foliage as in the shrubs described by Words- 

 worth : — 



" Like rock or stone they are o'ergrown 

 With lichens to the very top, 

 And hung with heavy tufts of moss, 

 A melancholy crop." 



The Branny borrera (B. furfuracea, Plate XV., Jig. 13) 

 was growing on the boles of trees in the highlands. Its 

 colour is rather brown than grey, and its narrower fronds 

 are lined with black ; a mealiness on the upper surface 

 procures for the plant the specific name of " branny." 



