2 JO 
Review: 
of the four vertical arms of the H-shaped bundle. A very curious 
point is the mode of emission of the branch-strands, which in this 
case form a double series on either side of the rachis. The two 
secondary bundles on each flank are separate at their origin, but 
coalesce after they become free, and finally separate again to supply 
the biseriate pinnae. 
In Chapter V. the systematic position of Stauropteris is very 
fully discussed; the author’s careful examination of all the details 
of the frond-structure and judicious weighing of the various 
possible objections strongly confirm the opinion that this remarkable 
type finds its natural place as a member of the Zygopterideae. 
In Chapter VI. of this Part certain genera are introduced which 
have hitherto been regarded as standing apart from the family. 
Gyropteris sinuosa, Goeppert, a petiole from Falkenberg, of Lower 
Carboniferous or perhaps Devonian age, is interpreted as having 
a Zygopteridean structure, though the curved bundle bears no 
obvious resemblance to that of the main petiole in any accepted 
genus of the group, and may be more appropriately compared with 
the secondary strands of Diplolabis or Metaclepsydropsis. 
A more surprising point is the inclusion of Tubicaulis in the 
Zygopterideas. This genus, from its stem-structure, appears to fall 
naturally into the Botryopteris- group, and to be widely remote from 
the true Zygopterideas. Dr. Bertrand, however, troubles little about 
the structure of the stem, and is able to make the simple, inversely 
curved foliar bundle fit into his Zygopterid scheme. He makes the 
genus the terminal member of the following phylogenetic series: 
Clepsydropsis, Metaclepsydropsis, Diplolabis, Gyropteris, Tubicaulis. 
Now, according to a note of Dr. Bertrand’s, published in the 
Comptes Rendus for last year, Clepsydropsis is the petiole of which 
Cladoxylon is the stem. If this be so, we must suppose, on the 
author’s view, that the highly complex, polystelic and secondarily 
thickened stem of Cladoxylon underwent reduction to the extreme 
simplicity shown by the undifferentiated protostele of Tubicaulis , 
a singularly bold hypothesis, for which an ingenious “reading” of 
the foliar bundle scarcely affords an adequate basis. 
The author is of opinion that the Tubicaulis Sutcliffii described 
by Miss M. C. Stopes is the stem of Anachoropteris rotundata ; he 
does not appear to have seen any preparations of Miss Stopes’ 
fossil, or he would probably not have ventured on this identification. 
The inclusion of Gyropteris and Tubicaulis in the Zygopteridem 
is, in the reviewer’s opinion, the most questionable point in the 
