four new British Lichens. 89 



in company with Mr. Dickson, on old pales that surround the 

 park of Miles Barnes, Esq. I am acquainted with no species, 

 either British or foreign, for which it can possibly be mistaken ; 

 and indeed it is nearly allied to hardly any, except Lichen spha- 

 rocephalus, from which the yellow powder of its tubercles affords 

 at first sight an obvious and certain difference : were it not for 

 this circumstance, it might in some cases be difficult to discrimi- 

 nate between the two plants, as it is well known that L. spharoce- 

 phahts, from being seldom provided with any crust of its own, has 

 been alternately placed among the Fungi and Lichens, and that, 

 though it generally arises from the naked trunk of a hollow tree, or 

 from a decaying post, it sometimes shoots up among other spe- 

 cies, thereby tending greatly to mislead an inexperienced obser- 

 ver. On this account it appeared at first sight so singular that 

 such tubercles as those of Lichen chrysocephalus should be found 

 with such a crust, that it was long before I could persuade my- 

 self they really belonged to each other ; but, after repeated ex- 

 aminations, I see them so constantly together, that I can no 

 longer feel doubts on the subject. This species most frequently 

 grows in irregularly oblong patches, about four inches long, and 

 two wide ; the pale though bright yellow of its crust makes it 

 conspicuous at a distance ; yet, unless closely examined, it is 

 easily overlooked for favus, candelarius, or some other of the more 

 common species. It belongs to Dr. Acharius's eighth tribe, the 

 Calicia, and must be considered a highly interesting Lichen, as 

 forming, together with L.inquinans of English Botany, a link that 

 unites the plants of this division with the crustaceous tribe. At 

 the same time, however, it deserves to be noticed, that many of 

 those referred hither in the Lichenographia Suecica hare no pre- 

 tensions to such a situation ; and, unless carried back to their 

 former place among the Fungi, must involve this difficult part 



VOL. VII. N °I 



