Possible Neiv Coal-Plants Etc., in Coal. — Gresley. 13 
anatomical structures on the left. From pyrites nodule in 
the coal at What Cheer, Iowa. 
Fig. 2. Transverse section of a pinna through o h fig. i, showing 
curling under of the rim or sides of the pinnae, and the 
position, shape and size of the mid-rib c. 
Fig. 3. Longitudinal section through a pinna, near the curving- 
under line (c fig. 2), showing cross section of the branching 
venation, the curved-under point of the pinna, and the stalk 
of the frond at d. 
Fig. 4. Another long section of a pinna between its mid-rib and the 
curving-under line, showing frond's mid-rib d, and the 
curved-under edge of the pinna e. 
Fig. 5. Rather oblique cross section of a pinna, showing curiously 
curved form. 
Fig. 6. The aspect of the exterior or upper surface of a pinna. 
Fig. 7. Details of the venation near the tip of a pinna. 
Fig. 8. Longitudinal section of part of a mid-rib, with branching 
or rebranching venation and associated cellular structure. 
Fig. 9. View of the underside of a pinna (restored). 
Note. In these pyrites concretions in the coal bed at What 
Cheer in Iowa, this species of Pecopteris is rather common. It 
was by grinding and poHshing that the structural details were 
"brought to light, and I am greatly indebted to Dr. David White 
of the United States Geological survey for suggesting that this 
fossil be figured, because probably of scientific value paleo- 
botanically. Instances of fossilized anatomical structures in 
the leaves of ferns are certainly very rare, in fact this is about 
the only case I can find or know of. 
Fig. 10. Transverse section of part of one of the What Cheer nod- 
ules, showing a portion of a row of pyrite-colored XXX and 
dots, separated by or embedded in a blackish substance. 
Fig. II. The aspect of the specimen fig. 10 after grinding and 
polishing obliquely. The material was evidently vegetable, 
and the structures seem to suggest the palm or the cane. 
Fig. 12. Fragment of mineralized cellular vegetable material 
(chiefly pyrite), showing pitted and punctate vessels of two 
or three kinds. From the coal bed at What Cheer, Iowa. 
Fig. 13. Coniferous? wood-cells and medullary ray? material, 
composed of pyrite etc., in the coal of What Cheer, Iowa. 
Note. The surfaces of these What Cheer pyritous nodules, 
while preserving a generally regular outline or contour, are in 
reality anything but smooth — they are decidedly rough ; the 
pyrites mixed with the coal laminre of the seam, and the coal 
on the other hand penetrates the pyrites. 
