392 Rev. W. A. Leigliton on the Britii^h Graphidese. 



LicTien lynceus, Sm. E. Bot. t. 809 (1800). 



Lecidea lyncea, Ach. Meth. 52 (1803). 



Opegrapha ccesia, DeCand. Fl. Fr. 2. 30.9 (1805) (fide Fries) ; Cheval. Hist. 

 Graph, t. 20. fig. 3 c, 4, 5 ; Flor. Paris, 531. 



Arthonia lyncea, Ach. in Schrad. N. Journ. Bot. 1. st. 3. p. 11 (1806); 

 L. Univ. 147 ; Syn. 7 ; Moug. & Nestl. Stirpes, 1158 ! 



Opegrapha notha, var. ccesia, Ach. Syn. 7Q (1814) (fide Fries, Borrer et 

 Martins). 



cymbiformiSyVar., Schser. Spicil. 51. 553 (1823-1842). 



Grapkis ccesia, Meyer in Spreng. Syst. Veg. 4. p. 1. 252 (1827). 



Lecanactis lyncea, Eschweil. Syst. Lieh. 14. fig. 7 (1824); Fries, L. Re- 

 form. 375. 



Leiogramma lynceum, Martins, Fl. Brasil. 1. pt. 1. .99 (18.33). 



Opegrapha lyncea, Borr. in Hook. Br. Fl. 2. 144 (1833); Bohler, Lieh. 

 Brit. no. 93 ! ; Sehaer. Enum. 158. 



On old oaks, and oak timber long exposed to the weather. 

 Sussex ! Mr. Borrer. New Forest, Hampshire 1 Mr. Lyell in 

 herb. Borrer. Oswestry, Shropshire ! Rev. T. Salwey. On the 

 'Beards Oak' at Penshurst, Kent ! Mr. W. Thompson. North- 

 amptonshire ! Rev. Churchill Babington. Hartshill Wood near 

 Atherstone, Warwickshire ! Donnington Park, Leicestershire ! 

 Rev. A. Bloxam. Thorndon Hall Park, Essex ! Mr. H. Piggot. 

 Great Malvern, Worcestershire ! Mr, E. Lees. Haughmond 

 Hill, Shropshire ! 



Thallus diffuse, thin, tartareous, white, pulverulent, cracked. 

 Lirella numerous, scattered irregularly over the whole thallus, 

 more or less crowded, very various and variable in shape and 

 size, of an orbicular, oval, oblong, or linear-oblong, or elongate 

 form, rounded and obtuse at both extremities, straightish or 

 curved and wavy, chiefly simple, but sometimes compound or 

 branched apparently from confluence, imbedded in the thallus, 

 and either level with or elevated above its surface. Disk broad 

 and expanded, flat, rough with minute points or elevations, 

 csesious, or pale bluish -grey with pruina, surrounded by a stout 

 rounded elevated black wavy proper margin, often inconspicuous 

 from excess of pruina or age, but with care always to be detected. 

 In vertical section, the receptacle of which the proper margin is 

 the upper edge is seen to subtend the whole of the sides and 

 base of the pale brown hyaline ascigerous disk, and to be ex- 

 panded below into a sort of torus, which penetrates the thallus 

 down to the bark on which the plant grows. 



Not to be confounded with Lecidea albo-atra, /3. corticola, 

 Sehaer. Exs. 445 ! to which it bears some general resemblance, 

 the structure of that plant being different, and the sporidia small, 

 broadly oblong, dark, 3-septate. Nor again with Opegrapha 

 cymbiformis 7. hebraica, A. coriicola, Schser. Exs. 98 ! in which 

 the lirellse in an old state are of somewhat similar appearance. 

 Nor to be regarded as a variety of Opeg. cymbiformis, Schser., 



