76 THE OLDER MESOZOIC FLORA OF VIRGINIA. 



of material for the formation of the coal. It is much to be regretted that 

 the strata overlying the main coal are never opened in the ordinary work- 

 ing of the coal, for they seem to be rich in a very interesting series of 

 plants. 



Plate XXXIX, Fig. 1, of natural size, will give some idea of the great 

 apparent width of the flat stem, for its entire width is not preserved, yet it is 

 over 2 centimeters wide. It represents the stem with the epidermis in place. 

 Plate XL gives the lower portion of a stem, but without showing any por- 

 tion of the petiole. It will be seen that here the leaflets are remote, unequal 

 in width, and at right angles with the stem. Plate XLI, Fig. 1, represents 

 the middle portion of the same leaf, and Plate XLII, Fig. 1, the upper part 

 of it without showing the summit. These three specimens all probably 

 formed portions of the same individual plant. If we join them together, 

 supply a petiole of proper dimensions, and imagine the leaflets prolonged 

 to the length of about 40 centimeters, we have the true dimensions 

 of this magnificent plant. Plate XXXIX, Fig. 3, gives a fragment of a 

 smaller specimen. Fig. 3 a is a slightly enlarged leaflet of it, to show the 

 nervation. Plate XLII, Fig. 1 a, is a portion of a leaflet with the nervation 

 enlarged very slightly, just enough to show the distinctness of the two strands 

 composing each bundle. Without the help of a lens they are not usually 

 seen so distinctly to be separate. Fig. 1 b represents an enlarged portion of 

 the base of a leaflet, giving the insertion of a single nerve-bundle, to show 

 the slow divergence of the branches after forking, which is very common 

 in the nervation of this plant. This represents what would appear, without 

 the help of a lens, to be a strong single nerve, which forks some distance 

 from its insertion. 



Formation and locality. — Found in great abundance at Clover Hill, in 

 fine-grained dark shale which comes over the main coal, and forms its roof. 



Ctenophyllum giganteum, spec. nov. 

 Plate XXXIX, Fig. 5. 



Leaf? Leaflets very large, 2S millimeters wide, nerves very strong and promi- 

 nent, forking near the base, and then single and parallel to one another and to the 

 margin of the leaflet. 



Only a fragment of a leaflet of this plant was seen, so that its true 



