of Bennettites gibsonianus , Carr. 431 
distinct proof of this cannot be obtained without an unlimited 
supply of material for making series of slices. The leaf-bases 
between the spadices are usually much out of shape, and the 
transverse section is irregular and distorted ; this makes it 
impossible, as a rule, to determine the precise relative position 
of the two kinds of organs. Where the spadices occur singly, 
they are indeed sometimes exactly over a leaf-base ; in other 
cases again they are thrust quite to one side. Displacements 
from pressure within the closed layer of contiguous organs 
would necessarily cause the disappearance of any positional 
arrangements which may have originally prevailed. But if 
the material at our disposal does not suffice to determine that 
the shoots in Bennettiteae were axillary, there is on the other 
hand nothing to show that they were terminal as in living 
Cycads, and that the stem which bears them was a sympo- 
dium. In no transverse section which we possess of any stem 
of Bennettiteae do we find even a trace of the bundle-system 
running into the pith, which is so characteristic of the flower- 
bearing termination of the axis in Cycadeae ; and where 
such shoots are so abundant as in the armour of Bennettites 
gibsonianus and other stems, it would be very strange if 
no section had ever hit upon a system of the kind. 
Each of the shoots terminating in spadices is composed of 
a large number of abbreviated internodes, and bears spirally 
disposed lanceolate acuminate cataphyllary leaves, biconvex in 
transverse section with two sharp edges. This is shown by 
Carruthers in figure 3 of plate 58 which gives the transverse 
section, and in figure 5 which is the oblique longitudinal 
section ; but the latter figure is not so clear as it would have 
been if the section had been truly median. The transverse 
section gives the axis of the shoot surrounded by its leaves, 
which are closely packed with no gaps, but with only narrow 
layers of the characteristic ramenta between them. There is 
an indication of the parastichies in the figure first cited. That 
these leaves are lanceolate and have no terminal lamina can be 
known for certain only where their surface, or the mould of 
it, is laid bare by the fracture. Here we can see both their 
H h 2 
