In the longitudinal section diagrammatically reproduced in fig. 146, D, cut along the line _ab_ of fig. 146, A, the parenchymatous tissue of the stout cushions has been partially destroyed, as at _a_; at _s_ is seen the section of a Stigmarian rootlet which has found its way into the interior of a cushion. Each leaf-trace is accompanied by a parichnos strand as in the true _Lepidodendron_; at the base of the leaf-cushion the parichnos branches into two arms which diverge slightly right and left of the leaf-trace, finally entering the base of the leaf lamina as two lateral strands (fig. 147, _p_). At one point in fig. 146, D the section has shaved a leaf-trace represented by a black patch resting on the parichnos just above the line _ef_, but it passes through one of the parichnos arms _p′_ which debouches on to the leaf-scar _sc_ at _p_. Had the section been cut along the line _cd_ of fig. 146, A the leaf-trace would have been seen in a position similar to that occupied by the parichnos _p′_ in fig. 146, D. [Illustration: FIG. 147. _Lepidophloios_ leaf-cushion in tangential section. (From a section in the Williamson Collection, British Museum, No. 1973.)] Fig. 147, A, affords a good example of a tangential section through a _Lepidophloios_ leaf-cushion, 1 cm. broad, like that represented in fig. 146, A, showing the vascular bundle _lt_, the two parichnos strands, _p_, composed of large thin-walled cells (cf. _Isoetes_, fig. 133, H, I), and the ligular pit near the upper edge of the section enclosing the shrunken remains of the ligule (fig. 147, B, _l_). [Sidenote: LEPIDODENDRON] Fig. 147, B, shows the form of the tangentially elongated leaf-cushions of _Lepidophloios_ and their spiral disposition. Fig. 146, F, represents a section similar to that shown in figs. 147, A and B, but in this case the leaf-trace, _lt_, and the parichnos strands, _p_, lie in a cavity formed by the destruction of some of the leaf-cushion tissue. It is worthy of notice that the parichnos cells have resisted decay more successfully than the adjacent tissue of the cushion. The diagrammatic sketches reproduced in fig. 146, H and I, were made from a transverse section similar to one originally figured by Williamson[259]: fig. 146, H, corresponding in position to the line _gh_ in fig. 146, A, passes through the ligular pit, _l_, and cuts across the parichnos in the act of branching; the leaf-trace passes outwards beyond the =Y=-shaped parichnos strand. In the other section, fig. 146, I, the parichnos is shown in a horizontal plane and the leaf-trace, _lt_, appears in oblique transverse section. In both sections and in fig. 146, G the shaded band at the base represents the secondary cortical tissue external to the phellogen.