58 NEW YORK STATE MUSEUM 
have been washed out and the cavity left filled with sand which has 
helped preserve the shape of the stumps in fossilization. The outer 
cortex, asin Lyginopteris, consists of interlacing strands of 
sclerenchyma tissue, forming a network (plate 6) or more or less 
parallel (plate 7). The cellular tissue which in the living trees 
occupied the space between the sclerenchyma strands is here replaced 
by sandstone. In a transverse section of the stem of Ly ginop- 
teris and the allied genus, Heterangium, the sclerenchyma 
appears in the form of dark radial bands, but in Eospermatop- 
teris it appears in the form of dots or short thick irregular lines, 
irregularly scattered. This zone of the outer cortex varies from an | 
inch or less to several inches in thickness depending upon the size 
of the stumps. In the majority of cases, the outside of the outer 
cortex is missing, but it is very well shown in several cases. The 
outer surface is marked with shallow ridges and furrows in some 
cases, giving the effect of a bark; in other cases the outer surface 
is only irregularly furrowed and wrinkled or even just roughened 
some of which is undoubtedly due to shrinkage in preservation. But 
in either case the outer surface appears to be composed of layers of 
sclerenchyma forming a kind of bark, which in the living tree 
undoubtedly had a covering of ramentum or fibers. The underside 
of the base of the stumps is quite strikingly furrowed in a radiate 
manner (plate 5) and in some specimens a depression is seen at the 
center. The base as well as the sides has the outer zone or covering 
of sclerenchyma layers above which is the zone several inches thick, 
varying according to the size of the stumps, of interlacing scleren- 
chyma strands. 
The interior structure of the trunk of Eospermatopteris 
for the present must remain unknown. There seems to be sufficient 
reason to believe that it belongs to the Lyginopterideae ; but whether 
it has a stele occupied entirely by the primary wood, with no pith, 
as in Heterangium?® or whether it has the large pith which is 
a constant feature of Ly ginodendron?® can not be determined 
from the material at hand. A transverse section of one of the 
smaller trunks shows toward the center an irregular, thin ring of 
sclerenchyma tissue and within this ring and to some extent out- 
side are irregularly scattered strands of sclerenchyma tissue. The 
oe Williamson, W. C., Phil. Trans. Roy. Soc., 1873, 163:377—408, pls. 22-31. 
Williamson, W. C. and Scott, D. H., Phil. Trans. Roy. Soc. (B), 1895, 
186 :703-779, pls. 18-20. 
See Seward, A. C., Fossil Plants, 1917, v. 3, ch. 29; see Scott, D. H., 
Studies in Fossil Botany, Pt. II, 1909, ch. 1o. 
