CRYPTOGAMIA ALGJE. 805 



• The cruil of this is compofed of black and white 

 tubercles, fo equally mixed that it is difficult to 

 fay which are moft predominant. The black tu- 

 bercles have often flat heads, and are fome- 

 . ^ times finuated on the margin. It is nearly re- 



lated to the T. calcareus. 



ceruko-m- l^ leprofus coerulrfcens, tuberculis nigricantibus. 



Bluifh Lichen, with black warts. Ani^Jis. 



Upon the Highland rocks, but not common. 



The crull of this is granulated, and of a blue-grey 

 colour, befct with numerous black, convex tu- 

 bercles, or warts. It fecms to be a diftintl fpe- 

 cies, though nearly related to the preceding. 



'vernalis ii L. leprofus albiilus, tuberculis fubrotundis ferrugi- 

 neis, Syjl. nat. edit. 13- />• 805. L. ferrugineus.. 

 Hudj.FL Ang. 444. {DiUen. mufc. i. 18, f. a.) 

 Vernal Lichen. Anglis. 



On the bark of trees, and fometimes on walls and 

 rocks. 

 . ,; There are two varieties of this, both with a tliin 



afh-colour'd or whitifn crult. The lirft has tu- 

 bercles of a brick-dud colour; the other fui- 

 cous, or brownilh ones, fomewhat foft and gela- 

 tinous, not fo diftind as the preceding, but 



crowded together. Neither have any circular 

 o 



, margins. 



Perhaps they may be didind fpecies. 



L, leprofus 



