Rev. W. A. Leighton on tlie British Unibilicariae. 293 



some specimens, but in others scarcely to be detected : the under 

 surface is quite smooth and naked, except occasionally a itt"^ 

 scattered fibres, which are either branched or simple, shorter and 

 usually much paler than those which fringe the edges of the 

 thallus : it is of a pale ash-colour near the centre, but gradually 

 darker towards the edges, where it is brown, with a greenish 

 tinge when moistened : substance coriaceous, flexible when moist, 

 extremely rigid and almost horny when diy, but still tough. 

 Tricce plentifully produced all over the thallus, and often 

 clustered, turbinate in their first state, afterwards becoming 

 supported upon extremely short peduncles, mostly orbicular, but 

 not unfrequently reuiform, surrounded by a nearly entire undu- 

 lated margin, nearly of the same height as the dis/c, so that the 

 whole surface is flat ; the gyri are mostly concentric, leaving in 

 the centre a subtriangular cavity, but are not rarely disposed in 

 various parcels, lying together without an}^ regular order." — 

 Lich. Brit. 



Specimens in my own herbarium collected " in alpibus Jemt- 

 landise " ! by Fries fil. ; " ad rupes in Pyrenseis orientalibus " ! 

 by Dr. Cam. Montague and M. Philippe, are identical. 



b. denticulata, Turn. & Borr. Edges of the thallus coarsely 

 fringed and toothed. 



Lichenoides comeum ^-c, Dill. 218. t. 29. f. 116 B. 

 Lichen prohoscideus, Sm. E. Bot. t. 622, two lower figures. 

 Gyrophora cylindrica, ^. denticulata, Ach. Metli. 107- 



cylindrica ot. (in part), Ach. L. Univ. 22'6. 



proboscidea, /3. denticulata. Turn. & Borr. Lich. Brit. 219. 



UmbiUcariu polymorpha, cc. cylindrica B, Schacr. Spic. 87 ; E.xs. 144 ! 

 polymorpha, ot. cylindrica, b. denticulata, Schacr. Enura. 26. 



Rocks about Loch Phadrick ! rocks, Ben-na-Bourd ! Mr. W. 

 Gnrdnei- in herb. Borrer. Clova ! Mr. G. Lawson. Summit of 

 Arran Mowddy ! M7\ Borrer. Gal ty more, co. Tipperary ! Mi\ 

 f. Carroll. 



In all respects similar to ' a,* except that the marginal fibres 

 are coarser and larger, and more evidently a prolongation of the 

 thallus. 



A " forma minor in alpibus maritimis Ligurise occiduse," re- 

 ceived by me from Prof. De Notaris, seems referable here. 



c. denudata, Turn. & Borr. Edges of the thallus almost 

 naked. 



Umbilicaria crinita, HofFra. PI. Lich. 2. 67. t. 44. f. 7- 



Gyrophora proboscidea, y. denudata. Turn. & Borr. Lich. Brit. 219. 



Umbilicaria polymorpha, x. cylindrica C, Schaer. Spicil. 9S ; Exs. 145 ! (not 



