of Bennettites gibsonianus, Carr . 423 
less disclose a greater affinity with the course of the vascular 
bundles in many Coniferae 1 . The structure of the bundles 
and of the secondary wood and bast must be further investi- 
gated, but this much is certain, that it shows great similarity 
to the same structure in recent Cycadeae. In Bennettites , as 
in Cycadeae, pith and cortex are permeated by more or less 
numerous gum-passages. The pith of B . peachianus , Carr., 
from the Jurassic of Sutherland in the north of Scotland, 
shows, besides these passages, peculiar irregular rings which 
have not yet been fully investigated 2 . Caruel 3 found some- 
thing of the same kind in his Raumeria cocchiana y and of this I 
have now at my disposal the material necessary for examina- 
tion, through the kindness of Professor d’ Ancona, of Florence. 
I have been able to determine that we are here dealing with 
periderms, of which a fuller account will be given in another 
place. I hope before long to be able to say whether this is 
the case in Bennettites peachianus also ; the other stems which 
have been examined hitherto show nothing of the kind. 
These stems, like those of recent Cycadeae, are inclosed in 
an unbroken armour of leaf-bases, the internal structure of 
which has been elucidated by Carruthers and shows no 
peculiar features. Each leaf-base is transversely rhombic in 
cross-section ; in its parenchyma lie numerous bundles which 
together form a rhomboid figure parallel to the contour of 
the section, except on the upper side where the two limbs 
bend downwards and inwards. The epidermis bears a large 
number of hairs, like the ramenta of Ferns, composed of one 
or more layers of tissue, and so close together as to form 
a regular felt which completely fills the fissures between the 
several leaf-bases. The tissue of the leaf-bases had very often 
rotted away before petrifaction, and only the epidermal layers 
and the masses of hair between them were preserved. In such 
1 See on this point Geyler, ‘ Ueber den Gefassbiindelverlauf in den Laubblatt- 
regionen der Coniferen,’ Pringsheim’s Jahrb. vi, tt. iv-ix ; and Bertrand and 
Renault, ‘ Recherches sur les Poroxylons,’ pp. 254-256. 
2 See Carruthers, loc. cit, pi. 62. 
3 See Caruel, as cited above. 
