OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
157 
lateral appendage like h' of fig. 2 reappears at e, but is now enclosed within an entire 
and separate circle of the tissue fig. 2, c, at c'. The supposed rootlets are also seen 
at d, and the carbonised cortical tissue at e. But outside the circular aberrant organ 
h' we now have a transverse section of a large Zygopteroid petiole. The H■'shaped 
section of the vascular bundle of this petiole is seen at f, surrounded by a ring of the 
structure c at c'. 
Fig. 4 represents a more perfect specimen of a similar Zygopteroid petiolar 
bundle, in which several of the tissues are well preserved. In the slenderness both 
of its central portion / and its two transverse ones // f”, this vascular bundle 
approaches nearer to Renault’s Zygopteris hihractensis than to any of the 
other forms hitherto described. In this specimen the cellular tissue of the cortical 
parenchyma is fairly well preserved, even in the dark masses, and is beautifully so at 
the two more central portions e, e. The anomalous zone c entirely invests this 
vascular bundle, like an endodermal zone. 
Fio-. 5 is a small detached vascular axis found close to a section like fio-s. 1 and 2. 
In its centre there exists a small vacant spot, a, from which there diverge four 
radiating lines, apparently repeating, on a small scale, the configuration of a, a in 
figs. 1 and 2. Fig. 5A is obviously a structure identical in its contour with fig. 3, 
€, but the middle of its central bundle approximates to fig. 5a. We have a point 
a, from which radiate three lines, a, corresponding to a' of figs. 1 and 2. These 
two examples, fig. 5, and especially 5a, seem to suggest that, whilst the organs figs. 
3 and 4, f, are destined to become true petioles, those of figs. 2, V, and 3, c, indicated 
by h', y are destined to become ordinary branches of the rhizome, like the centres of 
figs. 1 and 2. The vascular axis of each of these circular structures is obviously 
destined ultimately to assume the pentagonal form of that of the primary stems.'"' 
* On January 12tli of the present year, I received from Professor Stbnzel, of Breslau, a copy of an 
interesting memoir by him, entitled “ Die Gattung TuhicauUs, Cotta.” In this memoir the author 
figures and describes some examples of Cotta’s genus, and of Asterochlcena, Anachoropteris, and 
Zygopteris of CORDA. He sub-divides Asterochlcena into the sub-genera Meriopteris, Asterochlcena, and 
Clepsydropsis, and the genus Zygopteris into Zygopteris and Anhyopteris. Under the name of Zygopteris 
{Anhyopteris) scandens, this author describes and figures a plant 'which appears to me to be identical 
with my Rachiopteris Qrayii. In this plant Dr. Stexzel finds the organ which I have represented in 
fig. 2, b', and fig. 3, e, in exactly the same position as I have done, viz., between the exterior of the 
main stem and the superior or posterior side of the petiolar bundle, fig. 3, /. He also regards it, as I 
have done, as a young state of a stem or branch; giving to it the apparently appropriate designation of 
an axelsprosse. His specimens further show that the dubious investing zones of the several organs 
which I have indicated in my several figures by c and c are not mere mineral developments, but 
represent zones of tissue, often of a sclerenchymatous character, as I have already pointed out. He also 
thinks, as I have concluded, that the organs d, of my figures 1 and 3, ai’e true roots or rootlets. These 
agreements between two independent observers are, of course, satisfactory. As to the specific name of 
the plant, since my memoir was received by the Royal Society on June 13tb, 1888, whilst Professor 
Stenzel’s memoir has only been published during the present year, my name of Rachiopteris Grayii 
will have the precedence, unless Professor Stenzel has given the name to his plant in any earlier 
publication.—Eebruai’y 12th, 1889. 
