46 
Scott — 07 i a Palaeozoic Fern , the 
scalariform tracheides (forming the c filament ’ of Dr. P. Bertrand) (PI. I, 
Phot. 8 ; PI. Ill, Figs, i and 2 } x.e). At the ends, this band turns round 
and is continuous with the xylem of the antenna. The narrow space 
enclosed by the loop is occupied partly by very narrow tracheides, partly 
by a few elongated parenchymatous cells. The narrow tracheides inside 
the loop are no doubt the protoxylem ; I have detected ill-preserved 
spiral elements in this position in a longitudinal section. The protoxylem 
appears to form two groups, one near each end of the loop \px., Figs, i 
and 2 , PI. Ill), probably with one or more intermediate groups as well. 
On the inner side the loop is bounded by the ordinary xylem of the 
antenna, the tracheides in this position being only a little smaller than 
elsewhere. It will be seen that the structure agrees quite well with that of 
the peripheral loops in Ankyropteris bibractensis , var. westphaliensis, as 
described by Dr. P. Bertrand. 1 The agreement is especially evident where 
the antennae have become prominent, as shown in Fig. 2 . 
The external xylem-band or filament sometimes appears to be confluent 
with the antenna for considerable distances, the interior space of the loop 
then not being continuous (Fig. 2 ). 
The stages where the leaf-trace is separating from the axillary stele are 
not well shown in the new specimen. A trace in the act of division is 
present at l.t., a.s., in the section represented in PI. I, Phot, i ; the axillary 
stele is clear, but the foliar strand is much damaged. 
In the longitudinal series a foliar bundle is shown in very oblique 
section (PI. I, Phot. 9). This is seen some little way above its separation 
from the axillary stele, which is present in another section of the series 
(part of this stele is shown in PL IV, Fig. to). The foliar bundle repre- 
sented in Phot. 9 has, in fact, already entered the petiole. Its slender 
proportions and long antennae agree well with the structure of the bundle 
in Williamson’s original specimens (cf. PI. II, Phot. 16). The peripheral 
loop is quite evident, and at once identifies the bundle as that of an Ankyro- 
pteris. In the comparative straightness of the middle band (‘apolar’) and 
of the antennae the bundle differs widely from A. bibractensis , var. west- 
phaliensis , P.B. ; the original A. bibractensis of Renault is intermediate 
in these respects (Renault, ’ 69 , PI. IX). 
The swelling on the adaxial antenna, near its junction with the middle 
xylem-band, marks the presence of a lateral bundle, destined for a secon- 
dary rachis (PI. I, Phot. 9), as is more clearly shown in an adjacent section 
(2529). So far as can be seen, the mode of emission of the secondary 
bundle agrees with that described by Dr. P. Bertrand, but the obliquity 
of the sections leaves the details obscure. At any rate it is clear that the 
lateral strands were given off singly as in Ankyropteris , and not in pairs 
as in E tap ter is. 
1 ’09, p. 74, PI. IX, Figs. 62, 63, &c. 
