ACOTYLEUONS. LICHENS* Collema. 71 



* Thallus imbricated, plicated, suborbicular , composed of minute lobes 

 (when moist, thick and turgid). (Euchylium.) 



1. C. cheileum, thallus suborbicular imbricated, lobes thick all 

 minute rounded crenulated ascending, apothecia nearly plane 

 aggregated of the same colour as the thallus the margin crenu- 

 lated subevanescent. Ach. Syn. Lich. p. 310. Lichen mar- 

 ginatus, Bernh. in Schrad. Journ. 1799, v. \.p. 6. t. \.f. 2. a. 

 Dicks. Crypt, fuse. 4. p. 25. 



HAB. Roots of trees in shady subalpine woods, Dickson. 



2. C. melcenurn,) thallus orbicular somewhat stellated imbricated, 

 lobes cut and laciniated their margins elevated waved crisped 

 and crenulated, apothecia marginal nearly plane of the same 

 colour with the thallus their margin granulated. Ach. Syn. 

 Lich. p. 315. 



ft. marginale, lobes of the thallus deeply laciniated narrow multi- 

 fid spreading flexuose nearly plane crenate and lobed, apothecia 

 marginal and scattered dark brown their margin entire. Ach. 

 Syn. Lich. p. 316. Lichen marginalis, E. B, t. 1924. 



HAB. (3. Highlands of Scotland, Sir J. E. Smith, in E. B. 



3. C. fascicidare, thallus suborbicular imbricato-plicate, plaits 

 central erect flexuose, lobes of the circumference rounded in- 

 ciso-crenate, apothecia marginal turbinate fasciculate, disk 

 rather convex reddish. Ach. Syn. Lich. p. 317. Lichen fascic , 

 Lightf. p. 841. E. B. t. 1162. 



HAB. Shady places on the north sides of trunks of trees, not unfre- 

 quent, particularly on the ash, Dr. Burgess. Wood between Bal- 

 lacheulish and Linnhe Loch, Mr. Turner and Hook. 



* Thallus foliaceous ; lobes rounded, downy or Jibrillose beneath. 



(Mailotium.) 



4. C. saturnlnum^ thallus foliaceous blackish green glaucous and 

 downy beneath, lobes rounded waved entire, apothecia scat- 

 tered elevated plane reddish their margin entire. Ach. Syn. 

 Lich. p. 320. Lichen saturninus, E. B. t. 1980. 



HAB. Trunks of trees, Dickson. 



5. C. Burgessiij thallus foliaceous somewhat imbricated glaucous 

 greenish brown pubescent and somewhat spongy beneath, lobes 

 rounded sinuated crenulated and crisped, apothecia depressed 

 planish brown their margin foliaceous crisped. Ach. Syn. 

 Lich. p. 320. Lichen Burgessii, Lightf. p. 827. E. B. t. 300. 



HAB. Discovered upon trunks of hazel and birch in Dumfries-shire 

 by Dr. Burgess. Plentiful on trees by the side of Loch Lomond, 

 going to Tarbetj and near Inverary and Ballacheulish, Mr. Turner 

 and Hook. 



* Thallus foliaceous - } lobes submembranaceous, lax, naked, b'.ackish 



green. (Lathagrium). 



6. C. nigrescens, thallus foliaceous membranaceous submono- 

 phyllous orbicular depressed plaited rounded and lobed black- 



