Hickling — T he Anatomy of Palaeosiachya vera. 371 
of Dr. Scott. This examination has also brought to light certain new 
features which I think tend to modify, in some considerable degree, our 
ideas regarding the position occupied by Palaeosiachya in the Calamarian 
series of fructifications. 
A slightly revised account of the anatomy of this cone was published 
in the joint paper just referred to/ while Dr. Scott summarized his view 
regarding it, and gave an excellent figure of a transverse section in his 
collection, in his * Studies/ 2 
Considerable difficulty has been experienced in preparing a complete 
account of the anatomy of this cone. The state of preservation is only fair, 
and the sections themselves being old, are badly cut and thick. Conse- 
quently strong and carefully controlled illumination is necessary to make 
out the details. These difficulties, coupled with rapid working, are probably 
responsible for the numerous mistakes in Williamson’s account. 
General Features . I have little doubt that the general external appear- 
ance of this cone would be fairly represented by Weiss’s figure of his 
Palaeosiachya pedunculata . 3 In diameter our cone was about the same 
as Weiss’s specimen. Its length cannot now be determined, but it does not 
appear to have been short. It was pedunculate, and from the fact that 
four successive transverse sections passed through one peduncle, we may 
fairly conclude that that particular peduncle was not less than half an inch 
in length. The internodes had a length of about 4-7 mm. Round each 
of the swollen nodes of the axis were placed usually eighteen oblique 
sporangiophores, in the axils of about the same number of bracts. The 
bracts were free, but imbricating except towards the tips, first horizontal, 
then ascending. They probably hid completely the fertile parts from view. 
The sporangiophores were peltate, and each bore four sporangia, all the 
sporangia in a whorl being closely appressed. The axis was typically 
Calamitean in its anatomy, fistular, without nodal diaphragms, but with 
a complex system of supporting tissue in the cortex at each node. Text- 
Fig. 1 shows this sclerized tissue in longitudinal section. It formed a thick 
plate-like ring as described below, with (usually) nine unsclerized intervals, 
which now appear as £ canals ’ owing to the non-preservation of the soft 
parenchyma which formerly filled them. On the right side, the section 
passes through these canals. The soft tissue in them is imagined to be 
transparent, and the sclerized part to be seen through it. The eighteen 
bundles of the axis were approximated in pairs lying between these 
£ canals,’ as seen in PL XXXII, Fig. 7. The diagrammatic section shows 
clearly the anomalous course of the sporangiophore-trace, which is the most 
remarkable point now brought to light. It indicates also the swelling of the 
vascular tissue at the nodes by the addition of secondary tracheids. 
1 Williamson and Scott, ’94, p. 916. 2 Scott, ’00, p. 61. 
8 Weiss, 76, Taf. xv. 
