found it on the fallen trunk of a Walnut tree. It occurs, indeed,
on so many kinds of trees, that I have ventured to change
the specific name given to it by Mr S o w e r b y , who seems to
have considered the plant as peculiar to the Hornbeam.
Fig. 1. N. magna; natural size. Fig. 2. Section o f the stroma. Fig. 3.
Sporidia; magnified.
