268 Review: 
described in Chap. VI.; the author attributes to the present 
reviewer the opinion that the simple sporangial structure shows 
Stauropteris to be a primitive member of the Zygopterideae : as a 
matter of fact he quite agrees with the author that the frond- 
characters indicate a highly differentiated and specialized plant. 
In the second part the structure of the frond in Anhyroptens 
is described in full detail. Stenzel’s sub-genus is raised by Dr. 
Bertrand to generic rank, but with different and more natural 
limits. The type taken is the well-known British form commonly 
referred to Renault’s A. bibractensis, but here treated as a variety, 
under the name westphaliensis. The double-anchor shape of the 
foliar bundle is familiar. In the author’s terminology the middle 
bar is called the “ apolaire ” (from the absence of protoxylem); 
the four incurved “ flukes ’’ of the anchor are the “ antennes,” each 
terminating in a “ renflement re'cepteur,” while the outer bands of 
small-celled xylem constitute the “ filaments.” The tracheae (pro¬ 
toxylem) are placed internally at the four points of junction 
between the antennas and the filament, but the question whether 
other protoxylem-groups may not be distributed along the inner 
side of the filament is left open. 
In this genus only one series of branches is given off from 
each side of the rachis, but the branch-bundle is oriented at right 
angles to the main strand, and the second plane of branching is at 
right angles to the first. The mode of ramification of the frond in 
the Zygopterideae generally appears to be materially different from 
that of ordinary leaves. 
The complicated process of emission of the secondary bundles 
is, for the first time, fully worked out; the main point is that the 
continuity of the “ filament ” is never interrupted. The bundle of 
the branch is widely different from that of the main rachis ; the 
author shows much ingenuity in interpreting the former in terms 
of the latter, but the difference remains. The secondary branches 
of the rachis were named Rachiopteris inaequalis by Williamson. 
After some other fronds have been described, Chap. VI. gives 
a short sketch of the stems (or “stipes” as they are called by 
the Bertrand school) of Ankyropteris. The author regards 
Zygopteris Grayi (Williamson) as being probably the stem of A. 
westphaliensis, a view which scarcely seems likely to be correct, 
considering that Z. Grayi is a roof-nodule fossil, while A. westpha- 
liensis belongs to the coal-seam; neither does the identity of 
structure in the foliar bundle appear sufficiently proved. 
