142 Mr. Turner's Descriptions of Eight New British Lichens. 



first differs in being at its origin formed of a thin black crust, on 

 which the white glebules and black shields afterwards arise; 

 never, as far as I have seen, covering it, but giving the whole 

 plant a singularly varied appearance ; while in L. cceruko-nigri- 

 cans the glebules are always much larger, inflated, and wearing 

 a pruinose appearance, of which I never saw any traces in 

 X. aromatica. From L. parasema and all its affinities the widely 

 different crust and habit effectually remove it. 



Lecidea atro-flava. 



Lecidea crusta effusft tenui membranace& sub-granulosa atr&; 

 patellulis concavis flavis, margine integro elevato dilutiore. 



Tab. XI. Fig. 2. 



On flints upon the Downs about Brighton, Mr. Borrer. 

 Heaths near Bury. Rev. G. R. Leathes. 



Alga saxatilis, Crustacea, effusa. 



Crusta tenuissima, continua, laevis, in planta vetust& saepe hie 

 illlc praesertim centrum versus leniter granulosa, absque ordine 

 effusa, sed non rar6 ambitu pulcherrime fibrillosa, madefacta 

 seque ac siccata atra, aut atro-fusca, nitoris omnino expers. 



Patellulce frequentes, orbiculares, exiguae, juniores excavatae, 

 et margine crassiusculo tumente inflexo propemodum clausae; 

 in adultioribus discus explanatur, convexus, vel planiusculus, 

 sed margo semper elevatus, integerrimus ; color disci madefacti 

 aurantiacus, subdiaphanus, exsiccati laete flavus, margin is sem- 

 per dilutior. 



Substantia membranacea. 



The brilliant yellow shields of this Lichen form so lively a 



contrast with the dull black crust, that it deserves to be reckon- 



6 ed 



