ME. E. W. BINNEY ON SOME LOWEK-COAL-SEAM FOSSIL PLANTS. 
599 
show that the submergence was rapid, causing strong currents that tore up and drifted 
the trees. Every one of the floors of these coal-seams is full of the roots of Sigillaria ; 
so with the stems of these trees in the roof, the vegetable matter in the seam of coal, 
and the roots in the floor, there can scarcely be a doubt as to the remains of the vege- 
tables now composing coal having grown on the spots where it is now found, and that 
Stigmaria was the characteristic root of the plants which for the most part produced 
coal. 
The above conditions of the growth of vegetables in shallow seas very different to any 
state of things now existing, would require a plant suited to them and very different 
from any now living. After a careful investigation of the structure of Sigillaria elegans , 
Brongniart came to this conclusion : “ Tous ces motifs doivent nous porter a conclure 
que les Sigillaria et les Stigmaria constituaient une famille speciale entierement detruite, 
appartenant probablement a la grande division des Dicotyledones gymnospermes, mais 
dont nous ne connaissons encore ni les feuilles ni les fruits.” 
If we take particular parts of Sigillaria vascularis , as before described, we can trace 
resemblances to some living plants. The central axis when taken by itself might appear 
to connect the plant with ferns, as it certainly bears some resemblance to the root of 
Aspidium exaltatum, as figured by Brongniart in plate 8, figs. 10 & 11*. The internal 
radiating cylinder is somewhat like similar cylinders in Echinocactus and Melocactus , as 
figured by the same author. 
The vessels with barred and dotted sides in some respects resemble those of Zamia 
integrifolia , also noticed by Brongniart, and the outer radiating cylinder in the thick- 
ness of the walls of its tubes, or elongated utricles, and their arrangement, points to 
conifers. Although Sigillaria has resemblance in some of its parts to such widely 
different living plants, there can scarcely be a doubt in the mind of any one who has 
had the advantage of examining the fossil plant with its far extending roots and long 
radicles, but that it had an aquatic habitat. It attained a large size, as upright speci- 
mens have been traced by me nearly 60 feet in height without showing much dimi- 
nution in size, and the bases of others have come under my observation which have 
measured over 7 feet in diameter. 
Description of the Plates. 
PLATE XXX. 
IHploxylm cycadoideum. 
Fig. 1. Specimen (No. 1) of one-half of a stem of Diploxylon cycadoideum in a calcified 
state, found in the lower coal-measures of Lancashire, in the middle of a seam 
of coal, showing a transverse section : natural size. 
* Observations sur la structure interieure du Sigillaria elegans, p. 447. 
