Rev. W. A. Leighton on the Bntish Umbilicarise. 289 



dry. Tricce, except in their very youngest state, when they 

 appear as round blaek dots, depressed, and almost immersed in 

 the thallus, orbicular and reniform, surrounded when young by 

 a margin, which afterwards disappears. Disk at first flat, very 

 convex in a more advanced stage; its gyri arranged concen- 

 trically." — Lich. Brit. 



Doubtful if of British growth, but inserted on the authority 

 of Dillenius, whose herbarium contains only two specimens 

 (foreign ?), marked as having been received from Celsius. 



Distinct from U. hirsuta by the different sporidia (see PI. X, 

 fig. 12). 



Plate X. fig. 14. 



6. deusta, Linn. Thallus thin, crenate, slightly lobed, naked 

 on both sides ; upper side greenish-brown, rugged and reticu- 

 lated ; under, ash-coloured, smooth. 



Ldchen deustus, Linn. Sp. PI. UilS (cxcl. syn. Vaill. & Dill.) (1763), fide 



herb. Linu. cl. Borreio teste) ; Iluds. Fl. Angl. 550 (rev. Daviesio 



teste) ; Lightf. Fl. Scot. 2. 8fil. 

 proboscideus, Afzel. in Act. Stockh. 1788 (fide Ach.); Ach. Prodr. 147 



(in part). 

 Umbilicaria mesenterica, Schrad. Spicil. 103(1794). 

 Gyrophora proboscidea a,, (in part), Ach. ! Metb. 105 (1803) ; L. Univ. 220 ; 



Svn. 64 ; Sm. E. Bot. t. 2484 ; Turn. & Borr. ! Licb. Brit. 222; Hook. 



Fl. Scot. 2. 41 ; «, Brit. Fl. 217; Heppe, Fl. Wurzb. 69; Johnst. Fl. 



Berw. 2. 99 ; Chev. Fl. Paris. 1 . 644 ; Koerber, Syst. Lich. Germ. J>(i. 

 Gyromium proboscideum, Wahl. Fl. Lapp. 483 (1812); Fl. Cai-patb. 394 ; 



Fl. Suec. 857. 

 Umbilicaria polymorpha, ^. deusta, Schair. Spicil. 88. 363(1823-36); Kxs. 



148 ! ; Euum. (in part) 26. 

 Graphis corrugaia », Wallr. Crypt. Germ. 338 (1831). 

 Umbilicaria proboscidea a., (in part), Fries, L. Reform. 354 (1831) ; Sumnia 



V. Scand. 117 ; L. S. 128 (fide Nyl.) ; Nyl. N. Class. 157 ! 



St. Vincent's Rocks near Bristol and about Llauberris, Hudson. 

 Highland rocks of Scotland, Liyhtfuot. North of England and 

 Wales, Sir J. E. Smith. Rocks near the summit of Hedgehope, 

 Northumberland, Dr. G. Johnston. Ben Lawers, Scotland ! 

 Mr. Borrer. 



" Thallus peltate, flattish, but umbonated in the centre, and 

 rather elevated and undulated at the edges, consisting generally 

 of a single leaf, affixed to the rock by a thick callous central 

 disk, which scarcely ever forms any stalk, or sometimes, though 

 rarely, of many leaves growing together and diverging from a 

 common centre : leaf orbicular, from an inch to an inch and a 

 half in diameter, irregularly crenate at the edges, and often here 

 and there divided into a few shallow rounded lobes : upper sur- 

 face a dull greenish-brown when moist, when dry changing to a 



Ann. b^ Mag. N. Hist. Ser. 2. Fo/. xviii. 19 



