\)C) ADDITIONS TO THE BRITISH LTCIIEN-FLORA. 



flora of Great T5ritain. To record these, as well as to correct any 

 mistakes and omissions in my ' Enumeratio,' is the object of the present 

 article. 



Collema diffractiim, Nyl. — The plant so named by Jones, Mr. Carroll 

 informs me is the same as Pyrenopds rJiffundens, Nyl , and is, therefore, 

 to be omitted from the British list. 



C. aiiriculatnm (Hoffm.), Nyl. Syn. 106. — On decayed mosses on 

 shady walls in subalpine districts. Apparently rare, as at Appin, Ar- 

 gyleshire (Crombie), but may be expected to be met with elsewhere in 

 similar tracts. 



Pilophoron fibula, Tuck. L. N. Amer. 46. — On schistose mountain- 

 ous rocks. Rare and local, having as yet been detected only on Cader 

 Idris, Wales (Leighton), though from its external similarity to Stereo- 

 caidon cereolinum, it may probably have elsewhere been overlooked. 

 The previously recorded habitats for this interesting plant are the 

 White Mountains, North America, and Dianovagora in Finland. 



Usnea florida, var. riibiginea, Ach.— On trunks of trees in shady 

 woods, probably not uncommon in the South of England, as in St. 

 Leonard's and the New Forests. 



Usnea ceratlna, Ach. — In subalpine woods on aged pines, as at 

 Hafod, Cardiganshire, and Killin, Breadalbane. 



Cetrar'm aculeata, var. acanlhella, Ach. — Amongst mosses on the 

 ground in moorlands. Apparently not very common, as at Hill of 

 Ardo, near Aberdeen. 



Platysma cucullatum (Hoffm. PI. Lich. 66, 2). — On sterile ground 

 in alpine places. Extremely rare, and gathered only very sparingly 

 on the summit of Cairntoul, Braemar (Crombie). -Transition states 

 between this and P. nivnle are occasionally seen on. the higher moun- 

 tains of the same district. 



P. srepincola, * nlophyllum., Ach. — On Pine-trees and pales. This 

 is the form which most frequently occurs, at least in Scotland, the 

 other being there but rarely met with. 



Nephromium Imitaiiicum (Scheer.). — This is a distinct species, and 

 in addition to the Irish locality, has since been gathered in Appin, at 

 Dolgelly, and in Cornwall, and is probably not uncommon in the sub- 

 alpine tracts of West Britain. 



Parmelia cliscrela (Nyl.) = P. aljj'icola, Tii. Fries. — Abundant on 

 Morrone, Braemar, as also on Ben More, Breadalbane, and more 



