ME. E. W. BINNEY ON SOME LOWEE-COAL-SEAM EOSSIL PLANTS. 
591 
Whatever evidence Dr. Dawson had for supposing a large Fig. 2. 
Sigillaria to have been possessed of the obtuse top and the 
flat main roots, as shown in his restored specimen, figured in 
vol. xv. of the ‘ Quarterly Journal of the Geological Society,’ 
it is impossible to say, but certainly in all the numerous 
specimens which have come under my observation nothing 
has occurred to warrant me in supposing Sigillaria to be such a plant. Everything 
has led me to believe that the leaves and branches, and probably the fructification of 
Sigillaria, would prove to be very analogous to those of Lepidodendron. 
In order to show the identity in structure of specimens 2 & 3 with Sigillaria vascu- 
laris, previously described by me*, in Plate XXXV. fig. 5 is a specimen of Sigillaria 
vascularis from the same pit and seam of coal as the larger specimen No. 2, showing a 
transverse section, and fig. 6 exhibiting the external characters of the plant, part being 
covered with its bark, and part being decorticated, magnified 4 diameters. 
On comparing this specimen with those figured in Plates XXXI., XXXII., XXXIII., 
and XXXIV., the greatest difference is seen in the external characters of the stems ; 
but, as before stated, these can be traced from a regular rhomboidal scar, like that of the 
Lepidodendron, to the irregularly ribbed and furrowed Sigillaria. When we examine 
their internal structure it is found that their central axes are alike. The internal 
radiating cylinders are the same in both, making allowance for the greater age of the 
large specimen, each having been undoubtedly exogenous. The space on the outside of 
the inner radiating cylinder, filled with lax tissue and traversed by medullary bundles, 
is well marked and defined in the smaller specimen, much more so than in the larger 
one ; but neither show the nature and position of these bundles, which will be noticed 
more at large in a specimen from a different locality hereinafter described. The outer 
boundary of this space in the small specimen is marked by a well-defined line of carbon- 
aceous matter. The coarse cellular tissue on the outside of the latter, with the circular 
openings from which proceed the bundles of vessels traversing the outer zone of tubes or 
elongated utricles in radiating series, forming the outer cylinder, are the same in both. 
The term tubes, or elongated utricles, has been previously employed to denote the 
structure of the outer cylinder. The inner portion of this zone is made up of what 
appears to be coarse cellular tissue. This gradually elongates as it proceeds outwards 
into utricles, which in their turn pass into tubes of a quadrangular form, of which 
Fig. 3. 
the outer part of the cylinder is composed. The 
accompanying woodcut (fig. 3) represents a lon- 
gitudinal section of No. 8, described in Plate 
XXXV. figs. 5 & 6. From this it is seen that 
the elongated utricles are more prominent and 
numerous in the small specimens, whilst in the 
large specimens, like those in Plates XXXIII. 
& XXXIV., the tubes are chiefly seen. 
* Quarterly Journal of tlie Geological Society for May 1862, p. 106. 
