336 
Ruth Holden. 
In the British Museum, there is a single specimen of Cycadites 
Roemeri, also from the Wealden of Hastings (4). From this, 
through the kindness of Mr. Edwards, a few pieces of cuticle were 
obtained, which yielded excellent preparations. Fig. 8 is a photo¬ 
graph of one. At the extreme left may be seen the cells overlying 
the midrib on the upper surface of the leaf. Fig. 9 (the same region 
from another preparation at a higher magnification) shows that 
these cells are extremely like those covering the entire upper 
surface in the case of Cycadites Saportce, being sinuous-walled, 
arranged more or less in rows, and devoid of stomata. Toward the 
right, an intermediate zone may be seen, in which the cells have in 
the centre, small circular projections. These probably represent 
hair scars, as similar appearances have been noted by Nathorst in 
Pseudocycas Steenstrupi. The black line in the centre of Fig. 8 
represents the edge of the leaf, where the upper surface was not 
completely separated from the lower; at the extreme right is the 
midrib of the lower surface. From this photograph it is evident 
that the whole leaf is densely covered with stomata, with the 
exception of the tissue overlying the midrib on the upper surface. 
The structure of the midrib of the lower surface is not apparent 
from this photograph, but examination of the preparations them¬ 
selves indicates that it is identical with C. Saportce, except that its 
double nature is not equally obvious. 
In regard to the stomata themselves, they are so similar in 
both species that they may be advantageously considered together. 
As pointed out by Thomas and Bancroft (5), there is a general 
Cycadean type of stoma which varies but slightly in all living and 
fossil forms. Among the variable features, may be mentioned 
number of accessory cells, shape and size of guard cells, etc. 
Between extant and extinct, however, there is a further point of 
difference, dependent on the fact that in the former the xerophytic 
habit has caused an almost universal sinking of the guard cells with 
the consequent interposition of one or more series of intercalary 
cells between them and the accessory cells proper while in the 
latter, at least in the Bennettitales group, the stomata open directly 
on the surface. In Fig. 10, the structure of a few stomata of 
Cycadites Roemeri is shown; Text-Fig. 1a represents another at a 
higher magnification. If these be compared with Thomas’ figures 
of Anomozamites, Iaeniopteris, etc., it is obvious that there is a 
striking similarity, and that the genus Cycadites should be included 
in the Bennettitales group. 
