43 
Zygopteris Grayi of Williamson . 
var. westphaliensis (P. Bertrand, ’09, pp. 106, 109). Dr. Kidston, on the 
other hand, identifies the petiole of Z. Grayi with Z. di-upsilon y Williamson, 
which is a typical E tap ter is (Kidston, ’10). As we shall see, the new 
specimen is an unquestionable Ankyropteris ; as, however, it differs some- 
what from those previously described, it does not by itself suffice to settle 
the point in dispute, and reference to the other specimens will be necessary. 
Other questions on which the new specimen throws light are the 
morphology of the leaf-trace and axillary stele, the structure of the internal 
xylem, the position of the protoxylem, and the course of the bundles 
supplying the aphlebiae. 
The Shore Specimen. 
We will now go on to describe the Shore specimen. The specimen is 
from an ordinary seam-nodule and is accompanied by fragments of Lygino - 
dendron , Lepidodendron leaves, and other familiar objects of the coal-balls. 
In this respect it resembles Williamson’s later specimen (see above, p. 39) 
and the fragment originally described by him in 1874, while it differs from 
the specimens on which the species Z. Grayi was founded in 1888; the 
latter were contained in a roof-nodule and are accompanied by Goniatite 
shells. 1 This difference may raise a doubt whether all the specimens of the 
Z. Grayi type really belong to one species. The part of the Shore specimen 
from which my sections were cut was about two inches in length ; this piece 
was cut into twelve transverse and ten longitudinal sections, the latter 
coming immediately below the former. The transverse series is very good 
for following the whole process of the emission of the leaf-trace, 2 but it 
does not show perfectly the separation between leaf-trace and axillary stele ; 
the latter, however, is seen very well, both in transverse and longitudinal 
sections (PI. IV, Figs. 9 and 10), while the form and structure of the foliar 
bundle are fairly exhibited, though in oblique section (PI. I, Phot. 9). 
The general structure requires no long description, as it is in all essentials 
of the Zygopteris Grayi type, as recapitulated above. The maximum 
diameter of the stem is about 18 mm., that of the wood about 6 mm. 
The five-rayed, stellate wood is rather regular in outline, for even the 
shorter arms are well marked (PI. I, Phots. 1-6). The longer arms, about 
to give off a leaf-trace, are more conspicuously bicornute than in some other 
specimens, as corresponds to the form of the leaf-trace itself. A glance 
at PI. I, Phots. 4-6, shows that the leaf-trace has a very different form 
from that in the figured specimens of Z. Grayi or Z. scandens. In these 
1 In my review of Dr. P. Bertrand’s Etudes sur la Fronde des Zygopteridees (New Phytologist, 
vol. viii, 1909, p. 268) I erroneously stated that * Z. Grayi is a roof-nodule fossil’. This is only 
true of the type-specimens. The correction of this slip removes one objection to Dr. Bertrand’s 
suggested identification of Z. Grayi with Ankyropteris westphaliensis ; see, however, p. 57. 
2 A selection from the transverse series is shown in Plate I, Photographs 1-6, running from 
be low upwards. 
