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RECORDS OF THE AUSTRALIAN MUSEUM. 
space between them being again structureless. This section, which 
was prepared from a stem fragment enveloped in matrix in the 
hope that it would display the longitudinal structure simply, has 
by accident revealed other unexpected details, in the form of three 
bract-like bodies on each side, opposite to one another, two and 
two, those on the right being better preserved than those on the 
left. As sectioned they form an extension of the parenchymatous 
zone, and are margined by a continuation of the amber-brown 
exodermic layer, which is cellular, the tissue having the appearance 
of the epidermal of the fronds. The two lowest bodies are the 
longest and best preserved. The only suggestion I can offer of 
this structure is that the section at this point traverses a node, 
and that we here see petioles of some of the fronds. 
In the same section, but detached from this caudex fragment, is 
what may well be termed a root and rootlets (PI. xxiv.. fig. 13). 
The former is straight, 2*7 mm. long, with a transverse measure- 
ment of 1*5 mm., and from it on each side are given off at right 
angles longer and shorter processes, varying in length from 0*15 to 
03 mm. There is no structure preserved. Whether or no these 
are a root and rootlets of the plant under consideration, it is of 
course impossible to say. 
Could further points of structure be made out in this interesting 
fossil, a comparison might then be instituted with that of Lygino- 
dendron , Will., on the one hand, and that of j Heterangium^ Corda, 
on the other. On a superficial comparison with figures of both,* 
a general resemblance is noticable, particularly in the central 
cylinder, and the surrounding zone of secondary wood, but as we 
are unacquainted with the constitution of the central cylinder, 
whether of pith and primary wood, as in Lyginodendron , or 
primary wood alone, as in LLeterangium, f it is impossible to carry 
the comparison further. 
One very interesting point, however, remains to be referred to — 
the attachment of a fern foliage to stems with affinities of a higher 
order. The late Prof. W. C. Williamson suggested J that the 
rachises of certain ferns known as Rachiopteris aspera , from a 
similarity in some of their tissues to those of Lyginodendron , were 
the petioles of the leaves of that genus. He remarked — “ If we 
are correct in this supposition, we have now, for the first time, in 
Lyginodendron Oldhamium , a Fern of which the stem or rachis 
exhibits a highly developed form of exogenous growth. . . Some 
months ago Mr. Kidston sent me some stems which he believed 
* Williamson— Phil. Trans, for 1873, clxiii., pi. xxii., fig. 1 ; Williamson 
and Scott — Ibid. (B) for 1895, clxxxvi., pi. xviii., fig. 1; Seward — Ann. 
Bot., xi., pi. v., fig. l. 
f Williamson and Scott— Loc. cit. f clxxxvi., p. 745. 
I Phil. Trans. (B) for 1887, clxxviii., p. 298. 
