Notes. 
172 
The spores are considerably larger than the microspores of the 
Lepidostrobi. Those of the Burntisland Lepidostrobus , for example, 
are barely 0-02 mm. in diameter. The spores of our plant approach 
in size those of Sphenophyllum Dawsoni, or the microspores of 
Calamostachys C as he ana. 
The sporangial wall, as preserved, is only one cell in thickness ; it 
bears no resemblance to the palisade-like layer which forms the wall 
of the sporangium in Lepidostrobus , but has the same structure as 
that of a Calamostachys l . The sporangial wall of Sphenophyllum 
Dawsoni is similar. 
The anatomy of the axis of the cone agrees closely with that of the 
peduncle above described, except for the absence of any secondary 
tissues* The wood has twelve prominent angles, at which the spiral 
tracheae are situated, so its development was, no doubt, centripetal. 
The inner tracheae have pitted walls, and are intermixed with scattered 
parenchymatous cells, imperfectly preserved. The phloem has entirely 
perished. 
The most interesting anatomical feature is the course of the leaf- 
trace bundles, which can be followed with the greatest exactness on 
comparing sections in the three directions. 
A single vascular bundle starts from each angle of the stele for 
each sporophyll, and passes obliquely upwards. When less than 
halfway through the cortex, the trace divides into three bundles, 
one median and two lateral. The lateral strands are not always both 
given off exactly at the same point. A little further out the median 
bundle divides into two, which in this case lie in the same radial 
plane, so that one is anterior, and the other posterior. The median 
posterior bundle is the larger, and before leaving the cortex this, in 
its turn, divides into three. There are now six branches of the 
original leaf-trace, three anterior, and three posterior, which respec- 
tively supply the lower and upper lobes of the sporophyll. The three 
segments of the lower lobe are supplied by the two lateral bundles 
first given off, and by the anterior median bundle, while the upper 
segments receive the posterior median bundle and its two lateral 
branches. In the base of the sporophyll all six bundles can be 
1 See Weiss, Steinkohlen-Calamarien, Vol. ii, 1884, Plate XXIV, Figs. 3, 4, 
and 5 ; Williamson and Scott, Further Observations on the Organization of the 
Fossil Plants of the Coal-measures, Part I, Phil. Trans., 1894, Plate 81, 
Fig- 31- 
