202 The American Geologist. October, i899 
where and by whom such structures have already been pub- 
hshed (if it is considered that they have been), it would be a 
favor to the author of this paper, as well as a benefit to science 
which would be appreciated. 
It is to be regretted that so far, transparent sections of 
anthracite containing fossils have been impossible to make ; 
moreover all attempts to bring out structures in it, by polish- 
ing, have failed. All of the structures noted by me have been 
obtained by viewing the coal as opaque material. Having ob- 
tained the most satisfactory specimens from anthracite of the 
somewhat dull and more distinctly laminated grades, I will 
suggest that intending workers would do well to pay more at- 
tention to it than to the more dense black or less streaked 
lumps. 
It should be understood that the material of which the rod 
plant and the snake-spotted plant are composed is true coal — 
just as much as is the matrix enclosing them ; and they are so 
thoroughly part and parcel of each other, physically, that I 
have never been able to expose or free any portion of the outer 
surface of a specimen of the rind from the matrix, in order, if 
possible, to ascertain the appearance of the fossil's exterior. 
My experience with the material of the rod plant is that bitum- 
inous coal affords the best means of getting at and studying 
the rods per se, while anthracite enables one to better examine 
the tissues surrounding the rods as well as the plant's rind, 
its outline, and the way in which it occurs in the surrounding 
coaly medium. It should also be stated that nothing has been 
accomplished in the way of illustrations by photography. 
Specimens of the fossils have been submitted to experts for 
experiments in this way, but all of thern say nothing satisfac- 
tory could be obtained owing to the blackness of the coal or 
the impossibility of obviating the reflected light upon the shin- 
ing and uneven surfaces of the fractures carrying the objects 
required to be photographed. 
Reference to Plates VII and VIII. 
Figs. I to 14. External and internal views of '"rods" composed of 
compact, lustrous and duller coaly materials, occurring as scattered 
fragments, or in situ, upon the bedding-planes of coal. Fig. 4 shows 
a core of milk-white, brittle substance: fig. 10 a mass of clear (?) am- 
