The pith, 13–15 mm. in diameter, is rather larger than in _E. fasciculare_ and is characterised by the occurrence of dark sclerotic nests surrounded by radially disposed rows of parenchyma. The primary xylem strands are more numerous and smaller than in _E. fasciculare_ and these increase in diameter as they approach the secondary wood. In places the primary xylem elements form a more or less continuous band as in _Calamopitys annularis_. The largest leaf-trace bundles at the periphery of the pith are mesarch (fig. 458), but as each trace passes down the pith the reduction in the centripetal xylem is carried further than in _E. fasciculare_ until the xylem-strand becomes endarch in the lower part of its course. The secondary tracheids have usually two contiguous rows of pits and the medullary rays are one cell broad. [Illustration: Fig. 458. _Eristophyton Beinertianum._ A strand of primary xylem, showing the protoxylem, _px_, abutting on the secondary xylem. (× 35. After Zalessky.)] There can be no doubt as to the generic identity of the two species referred to _Eristophyton_, but the question as to the degree of affinity to _Calamopitys_ is more difficult to settle. There is force in Zalessky’s contention that these two stems should not be retained in _Calamopitys_: the recently described American species, _C. americana_ Scott and Jeffrey, gives emphasis to the view that the restriction of _Calamopitys_ to the German (and American) types is the safer course. While _Calamopitys_ as thus restricted is almost certainly a Pteridosperm, the inclusion of the types referred to _Eristophyton_ in the same category rests on a more slender basis. =CLADOXYLEAE.=