281 Riv. W. A. lii'ighton on the British Umbilicaria^. 



or very minuU'ly piipillosc : milistaiicc coriiiccous, tliickish, ili-y- 

 ible wluMi moist ; riirid, almost horny, but toiiirb, when dry. 

 Trica sbghtly i-U-vated, orbicular, varying to angular and subro- 

 niforin, somewhat convex ; their maryin entire, scarcely elevated ; 

 gyri of the dhk sometimes coucentric, but more iVequcntly dis- 

 posed in several irregular groups, usually, not constantly, h.-aving 

 a minute cavity in the centre. 



The tVngment ot" a specimen from AJr. Robson in herb. IJorrer 

 has all the a|)pearanee of Ijelonging to 7. hifpcrljorca. It sdcms 

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

 plant. 



Plate X. fig. fi. 



e. erosa, IIofFm. Thallus thickish, splitting when old into two 

 or three lamina?, jagged and somewhat lobed, perforated; upper 

 side greenish-brown, naked, divided by tlexuosc anastomosing 

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

 pierced, fibrous. 



Lichenoides rugosxim durum pullum, peltis atris verrucosis. Dill. 220. t. liQ. 



f. lis (I74I) (fide licrbiirii Dilleniaui d. Liglitfootio tt'stc, /. c. infra). 

 Lichen ])olyrrhLos, Iluds. Fl. Angl. 550 (cxcl. syu. Liuii.) (1778). 

 torrefactus, Lightf. Fl. Scot. 2. 8C2 (1777) (sec. speciin. a Liglitfootio 



seip.so rccepta cl. IJorrero teste in Lich. Brit. cit. infra) ; With. Arr. 4. 



(52 (e.xcl. svn. praiter Dill.). 

 erosus, Web. Spicil. 259 (177B); Swartz in Act. Ups. iv. 250 (fide 



Acl). & Scha;r.) ; Ach. in Act. Stockh. xv. 87. t. 2. f. 1 ; Prodr. U5. 



rctkuhiris, Wcstr. in Act. Stockli. xiv. -45 (fide Acli.) (17.93). 



Umbilicaria torrefacln, Sclirad. S])icil. 104 (1794). 



Lichen CriljeUinn, Retz. Fl. Scand. 2H7 (1795). 



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



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

 Umbilicaria erosa a, Scha;r. Spicil. !>3. 3f)4 ; Exs. 153 ! ; ICnuni. 29; Stcnh. 



in Sched. Crit. fasc. 5 & 6. no. 127 ; Fries, L. Reform. .'i51 ; Snmma 



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



Nvl. N. Class. 175 ! 

 (Jyrop'hora erosa, Ach. Meth. 103 ri803) ; L. Univ. 224 ; Syn. 65; Sm. 



K. lU.t. t. 2066 ; Mong. & Ncstl. Crvpt. Vosges. 250 ! ; Turn. & Borr. ' 



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



Ilib. pt. 2. 155; Kocrber, Svst. Lich. Gcnn. ^.Hy. 

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

 Graphis anea, 8. dispansa Sy e. cribrosa, Wallr. Crypt. Germ. 342 (1831). 



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

 Bristol, Hudson. Llanbcrris, Rev. Huyh Davies. On the vitri- 

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

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

 in Ireland, Dr. Taylor. Corry I.eesc, IJen Nevis ! Mr. Burrcr. 

 Ben Heck ! Craig Koynoch ! Mr. JF. Gardner in herb. Borrcr. 

 Clova ! Mr. G. Lawson. Capel Cerig, North Wales ! Mr. U. 



