A conspicuous feature of the stem of _forma α_ is the occurrence of two double rows of vascular strands stretching across the cortex (fig. 439, A, _a_, _b_). These are interpreted by Scott as downward continuations in the stem of the inner surface of leaf-bases. The outer cortex of the stem and leaf-bases has hypodermal strands of stereome which remain separate or rarely anastomose, and form a superficial zone exactly like that of some species of _Medullosa_. The leaf-trace bundles may be radially symmetrical or unilateral in the arrangement of the xylem which is in all cases completely surrounded by phloem. Fig. 439, B, shows part of a longitudinal section of a large leaf-trace bundle: spiral protoxylem elements (_px_) abut on the phloem (_ph_) and are succeeded to the left by narrow scalariform and large reticulately pitted tracheids. In the larger and radially constructed traces there are several protoxylem-strands distributed over the surface of the xylem, while in the smaller unilateral traces there may be one or two protoxylem strands. A characteristic feature of the xylem of the leaf-traces is the admixture of parenchyma with the tracheids (fig. 439, B, E) and another noteworthy character is the occurrence of large thin-walled tubes in the phloem described by Scott as sieve-tubes and compared with the large sieve-tubes in Marattiaceous leaf-bundles. Immediately internal to the hypoderm is a row of leaf-bundles (fig. 439, A) each of which is accompanied by stereome strands. The petioles, which reach a diameter of 12 cm., contain numerous, occasionally anastomosing, concentric bundles. Nothing is known of the fronds as a whole beyond the fact that they are spirally disposed and had decurrent bases of large dimensions in proportion to the stem. _Sutcliffia insignis, forma β._