It is clear that some at least of the stems referred to the genus _Bucklandia_ bore flowers of the _Williamsonia_ type[1099], and it is not improbable that the stems described by Dr Stopes as _Cycadeoidea Yatesii_ and _C. buzzardensis_ (fig. 578) possessed fertile shoots comparable with those of the Middle Jurassic species _W. gigas_. Dr Stopes’s contribution, while establishing a close agreement in anatomical features between some Lower Cretaceous stems and those of _Cycas_, does not warrant the further conclusion that these stems were in other morphological characters closely allied to modern Cycads. The main features of _Cycadeoidea_ may be summarised as follows: The principal trunk is generally unbranched (fig. 507) and identical in habit with some species of _Macrozamia_, _Dioon_, and _Encephalartos_ (cf. figs. 379, 382); in some species, _e.g._ _Cycadeoidea Marshiana_, _C. superba_[1100], _C. nana_[1101], the plant is represented by several approximately equal, thick, tuberous stems, in some cases easily separated from one another: a similar clustered habit is exhibited by certain forms of _Encephalartos_. The size of a _Cycadeoidea_ trunk varies from a few centimetres in length with a diameter of similar dimensions, as in _C. pumila_, to over a metre long as in _C. gigantea_ (fig. 535), or as much as 3–4 metres in _C. Jenneyana_ with a diameter of about half a metre. The surface is covered with persistent leaf-bases, exactly as in many recent Cycads, embedded in a thick mass of ramental scales which often stand out as a prominent reticulum, the petioles having partially decayed before the penetration of the mineralising solution through their harder tissues (fig. 507). On the conical terminal bud preserved in some stems (fig. 536) the foliage-leaves are replaced by linear scales. The leaf-bases often show the vascular bundles which form a simpler system than in the majority of recent species, their arrangement being, as Wieland says, more Fern-like; they form a series of collateral strands following the outline of the petiole-base[1102] with a U-shaped invagination in the middle of the upper face (fig. 517, A). Beyond the structure of the bundles at the base of the fronds and in the cortex of the stem our knowledge of the anatomy of the vascular supply of the rachises is very meagre. At the petiole-base each bundle consists either entirely of radial rows of centrifugal scalariform tracheids and medullary rays usually one-cell broad (fig. 519, B) or of centrifugal and centripetal xylem in varying proportions. The ground-tissue is well supplied with large secretory canals and in the larger leaf-bases there is a considerable development of periderm at the surface (fig. 517, B) as in recent Cycads. The ramenta formed from the epidermal cells consist in most species of fairly broad scales one-cell thick at the edges and broader in the middle; in _Cycadeoidea nigra_[1103] they are generally one-cell thick throughout and similar ramenta are