41Q 
imbricated, surface, from which seem to proceed a considerable 
number of thin, narrow leaves, by which it has been surrounded. 
Its resemblance to any known plant is not sufficient to have allowed 
any one to point out, with any confidence, the plant of which it 
may have been a part. Scheuchzer thought it most resembled 
“Equisetum, adhuc tenellum, in densam foliorum spicam, con- 
gestum; vel spica plantse alicujus hactenus ignota.” Walch ima- 
gined it to bear some analogy with the Myriophyllon, Linnaei. 
Perhaps, he says, it may be Millefolium aquaticum, flosculus ad 
foliorum nodos. The stalk, however, which, if not imbricated, has 
a regular reticulated surface, proves it not to belong to either genus. 
The ingenious Mr. Martin, in his descriptions of the petrifactions 
of Derbyshire, considers this fossil as the stalk or stem of some lost, 
or, at least, unknown vegetable, somewhat resembling a cone of the 
fir-tree. 
The fragments contained in the nodule Fig. 3, and 4, are not suf- 
ficiently perfect to lead to any conjecture, as to the plant to which 
they belong. They, however, serve, with Fig. 1, and 2, already de- 
scribed, to illustrate the circumstance of the two surfaces of the 
divided nodule representing the same side of the leaf, as will be 
attempted to be explained in our next Letter. 
A similar specimen with that represented Plate V. Fig. 3, has also 
been depictured by Volckman, from a schist from Silesia, whence 
this specimen was also said to have been obtained. He describes it 
as Rubia sylvestris, or molluga montana ; Gallium album latifolium. 
Gasp. Bauhin ; Gallium album, Tournefortii. ^ M. Walch states it 
to have been the opinion of M. Gunther, that it is the Rubia parva, 
flore caeruleo, cauliculos per terram spargens, Joh. Bauhini. Lhwydd 
has also figured it, Tab. Y. Fig. 202, and describes it as Rubeola 
mineralis, a fodinis Actonensibus, p. 12. Fig. oi the same Plate, 
seems to represent a part of the same plant, in an erect position, 
manifesting it to be one of the verticillates; and, perhaps, also show- 
