I have copied Dr. Greville’s specific character and description, 
and refer to his excellent figure m the ‘ Scot. Crypt. Flora.’ The 
“ tubercles” above described are evidently young ceramidia ; the 
specimen having been collected just as they were putting forth. 
It is obvious from an inspection of the figure that they are 
metamorphosed ramuli, occupying exactly the position of ramuli. 
They are profusely scattered over all the branches of the speci- 
men I examined. 
Fig. 1. PotystpHonta sPINULOSA :—the natural size. 2. A branch. 3. A 
small branch and ramuli, with apical fibres and young ceramidia. 4. Cross 
section of one of the smaller branches. 5. Cross section of the stem :— 
all more or less highly magnified. 
