600 MR. E. W. BINNEY ON SOME LOWER-COAL-SEAM EOSSIL PLANTS. 
Fig. 2. A longitudinal section of the same specimen taken across the minor axis from 
d to d in fig. 1 : natural size. 
Fig. 3. A tangential section of the same specimen taken across the upper part : natural 
size. 
Note . — The same letters indicate the same parts in this and the preceding 
figures, and also in the subsequent ones. 
a a. The middle part, showing the central axis or pith composed of large 
hexagonal vessels, having all their sides barred by transverse striae. 
a ' a'. The smaller hexagonal vessels in the central axis or pith found some- 
times interspersed amongst the larger ones, and divided by horizontal septae. 
a!’ a!'. Small vessels of very delicate elongated tissue found mixed with the 
other vessels in the axis or pith. 
b b. The vascular internal cylinder, in wedge-shaped bundles and radiating 
series, composed of hexagonal vessels, barred on all their sides by trans- 
verse striae, and divided by medullary rays or bundles, b" b". 
V V . Portions of the same cylinder disarranged or destroyed. 
b" b”. Medullary rays or bundles passing through the internal cylinder, and 
extending to the outside of the stem. 
c c. Space on the outside of the internal cylinder, composed of lax cellular 
tissue, and traversed by vascular bundles frequently disarranged or destroyed 
and replaced by mineral matter. 
d d. Outer cylinder of tubes or elongated utricles in wedge-shaped bundles, 
and radiating series of quadrangular form, divided by wide openings filled 
with coarse muriform tissue, which enclose medullary rays or bundles of an 
oval or circular form leading to the leaves. 
d 1 d'. Medullary rays or bundles of barred vessels traversing the coarse muriform 
tissue. 
d’ 1 d". Elongated tissue divided by horizontal septae (muriform tissue) sur- 
rounding the medullary rays or bundles. 
Fig. 4. A transverse section of a portion of the same specimen taken across the minor 
axis, showing the whole of the central axis or pith, one side of the inner 
radiating cylinder, and the space between the latter and the outside of the 
stem : magnified 5 diameters. 
Fig. 5. A longitudinal section of the same specimen, showing the same parts of the stem 
as are named in the last figure, magnified 5 diameters. 
Fig. 6. A tangential section of the same specimen (upper part), magnified 5 diameters, 
