Although in many respects the genus _Bothrodendron_ agrees very closely in habit and in its anatomical features with _Lepidodendron_, there are reasons for referring it to a distinct family of Palaeozoic Lycopods. As the following description shows, the external features do not differ in any essential points from those of certain types of the genus _Sigillaria_, particularly such a species as _S. rimosa_, Gold.[608], which has recently been refigured and described by Nathorst[609] from Goldenberg’s type-specimen in the Stockholm Museum. The small size of the leaf-scars is, however, a characteristic feature of _Bothrodendron_ (fig. 212, F); but a more important point is the fact that in a recently described[610] English example of a cone of _Bothrodendron_ (fig. 216), the sporangia are very like those of recent Lycopods, and differ from the radially elongated sporangia of _Lepidostrobus_. On the other hand, a French cone described by Zeiller[611] as _Lepidostrobus Olryi_, which is probably a strobilus of _Bothrodendron_, has the radially elongated type of sporangium (fig. 212, E). The comparative abundance of _Bothrodendron_ in Lower Carboniferous and Devonian rocks points to the greater antiquity of this member of the Lycopodiales as compared with _Lepidodendron_. The name _Bothrodendron_ was instituted by Lindley and Hutton[612] for impressions of stems from the English Coal-Measures, characterised by two opposite rows of large depressions like those shown in fig. 211 and, in one of the specimens, by “a considerable number of minute dots, arranged in a quincuncial manner.” The minute dots were recognised as leaf-scars and the cup-like cavities were described as probably connected with the occurrence of large cones. On very slender evidence this Palaeozoic plant, which was named _Bothrodendron punctatum_, was considered by these authors as probably a member of the Coniferales. The large stem from the Coal-Measures in the neighbourhood of Mons, Belgium, shown in fig. 211, affords a good illustration of _Bothrodendron_ in a partially decorticated condition, exhibiting a row of depressions similar to those on the Ulodendron form of _Lepidodendron Veltheimianum_ (fig. 157), but distinguished by the eccentric position of the scar at the bottom of each cup-shaped cavity: in the Belgian specimen, which is partially decorticated and shows the leaf-traces as small dots, the depressions have a diameter of 9 cm. It is believed by some authors that these Ulodendron shoots of _Bothrodendron_ and _Lepidodendron_ owe their characteristic appearance to the pressure of large cones, but, as I have already stated, there are reasons for preferring the view that these crater-like hollows are the scars of deciduous branches. Our knowledge of the strobili borne by Bothrodendron stems is still meagre, but we have no reason to assume the existence of any cones large enough to produce by the pressure of their bases such depressions as those shown in fig. 211. In one