28i Rev.W. A.Lcighton on the British Unibilicarise. 



or very minutely papillose : substance coriaceous, tliickish, flex- 

 ible when moist ; rigid, almost horny, but tough, when dry. 

 Tricce slightly elevated, orbicular, varying to angular and subre- 

 niform, somewhat convex ; their margin entire, scarcely elevated ; 

 gyri of the disk sometimes concentric, but more frequently dis- 

 posed in several irregular groups, usually, not constantly, leaving 

 a minute cavity in the centre. 



The fragment of a specimen from Mr. Robson in herb. Borrer 

 has all the appearance of belonging to 7. hyperborea. It seems 

 scarcely sufficient to enable us to form a decisive opinion on this 

 plant. 



Plate X. fig. 6. 



€. erosUi HofFm. Thallus thickish, splitthig when old into two 

 or three laminae, jagged and somewhat lobed, perforated ; upper 

 side greenish-brown, naked, divided by flexuose anastomosing 

 lines into convex areolae; under side paler, papillose, separately 

 pierced, fibrous. 



Lichenoides rugosum durum pullum, peltis atris verrucosis, Dill. 220. t. 30. 



f. 118 (I74I) (fide herbarii Dilleniani cl. Lightfootio teste, I. c. infra). 

 Lichen polyrrhizos, Huds. Fl. Angl. 650 (excl. syn. Linn.) (1778). 

 torref actus, Lightf. Fl. Scot. 2. 862 (1777) (sec. specim. a Lightfootio 



seipso recepta cl. Borrero teste in Lich. Brit. cit. infra) ; Witli. Arr. 4. 



62 (excl. syn, praeter Dill.). 

 erosus, Web. Spicil. 259 (1778); Swartz in Act. Ups. iv. 250 (fide 



Ach. & Schser.) ; Ach. in Act. Stockh. xv. 87. t. 2. f. 1 ; Prodr. 145. 



reticularis, Westr. in Act. Stockh. xiv. 45 (fide Ach.) (1793). 



Umbilicaria torrefacta, Schrad. Spicil. 104 (1794). 



Lichen Cribellum, Retz. Fl. Scand. 287 (1795). 



Umbilicaria erosa, Hoffm. Fl. Germ. 2. HI (1795); PL Lich. 3. fasc. 4. 7. 



t. 70 ; DC. Fl. Fran?, ed. 3. 2. 411. 

 Umbilicaria erosa cc, Schaer. Spicil. 93. 364 ; Exs. 163 ! ; lllnum. 29; Stenh. 



in Sched. Crit. fasc. 6 & 6. no. 127 ; Fries, L. Reform. 354 ; Summa 



Veg. Scand. 117; Tuckerm. ! Syn. 73; Massal. Ricerch. 62. fig. 116; 



Nvl. N. Class. 175 ! 

 Gyrophora erosa, Ach. Meth. 103 (1803); L. Univ. 224; Syn. 66; Sm. 



E. Bot. t. 2066 ; Moug. & Nestl. Crvpt. Vosges. 250 ! ; Turn. & Borr. ! 



Lich. Brit. 229 ; Hook. Fl. Scot. 2. 42 ; Brit. Fl. 2. 218 ; Tayl. Fl. 



Hib. pt. 2. 155 ; Koerber, Syst. Lich. Germ. 96. 

 Gyromium erosum, Wahl. Fl. Lapp. 482 (1812) ; Fl. Suec. 856. 

 Graphis cenea, b. dispansa ^- e. cribrosa, Wallr. Crypt. Germ. 342 (1831). 



Highlands of Scotland, Lightfoot. St. Vincent's Rock near 

 Bristol, Hudson, Llanberris, Rev. Hugh Davies, On the vitri- 

 fied forts in the Highlands of Scotland; Durham; Yorkshire; 

 North Wales, Sir J. E. Smith. Mangerton and other mountains 

 in Ireland, Dr. Taylor. Corry Leese, Ben Nevis ! Mr. Borrer. 

 Ben Beck ! Craig Koynoch ! Mr. IV. Gardner in herb. Borrer. 

 Clova ! Mr. G. Laivson. Capel Cerig, North Wales ! Mr. H. 



