332 THP: CKYPTtXiAMIC FLORA OF KBNT. 



This species may be known from F. canina by its smaller 

 size, reddish colour when damp, revolute apothecia, and thick 

 nerves on the under surface of the thallus. 



P. POLYDACTYLA, Hojf'm. 



On damp mossy banks in hilly districts. 



Ightham, Ohkubo ! Ide Hill, near Sevenoaks ; Halstead ; Lydd 



Beach. 

 Distinguished easily by its smooth not powdery dark grey 

 thallus and numerous apothecia. 



P. HORIZONTALIS (L.) 



On damp rocks, among mosses, &c. ; rare. 



Ightham. 



Known at once by the horizontally placed, flat apothecia. 



Parmeliei. 

 Stictina limbata (Sin.) 



Usually on trees near streams in subalpine districts. E. B. 



t. 1104. 

 On stunted prostrate blackthorn bushes, Lydd Beach ; rare. 



S. FULIGINOSA (Dicks.) 



Growing generally on trees and rocks in subalpine districts. 



E. B. t. 1103. 

 On stunted blackthorn bushes, Lydd Beach ; rare. 



S. SCROBICULATA (Scop.) 



On trees and rocks in subalpine districts. E. B. t. 497. 



A smgle specimen on a tree at Ightham Common ; Hoivse ! 

 Extremely abimdant at Lydd Beach, growing on the sandy 

 ridges with Cladonia gracilis, C. alcicornis, &c. 



The occurrence of the last three subalpine lichens a few feet 

 above the level of the sea is worthy of note, for nowhere else in 

 Kent have they been found as yet. The Hchen-flora of this 

 singular region is remarkable for the large number of species 

 which are subalpine in character. Their presence here can only 

 be accounted for by supposmg the spores or gonidia to have been 

 blown by the south-west wdnd either fi'om the Dartmoor Hills or 

 the New Forest, and to have been deposited on the low ground 

 when the wind met the hills behind Eomney Marsh. A few 

 of these lichens such as Cladonia gracilis, Cladonia alcicornis, 

 Nephromium lusitanicum, Cetraria aculeata, and Stictina sc7'obiculata, 

 are to be found, the first three well-fruited, in abundance on the 

 sandy ridges which are scattered over the pebbles. Stictina 

 limbata, S. fuliginosa, and Parmelia plumbea, are found sparingly 

 only on the stunted, prostrate blackthorns near the ponds, while 

 Physcia Jlaricans and Sticta jndvumacea occur most profusely, the 

 former on small erect bushes, growing with the subalpine moss 

 AntitricJtia curtipendida, in the greatest luxuriance, and the latter on 

 the sand not far from the cultivated fields, while the pebbles them- 

 selves are abundantly covered with Lecanora gibbosa and Lecidea 

 petrcca. These with numerous Eamahnas and ParmeHas form the 



