232 A. G. r ansley. 
differ from the young condition only by the presence of a greater 
number of leaf-trace strands, which branch and anastomose freely. 
The petiolar structure corresponds in a general way with that of 
Arcliangiopteris, though the petiole possesses more internal strands. 
Ct 
Fig. 76. Kaulfussia ascnlifolia. Vascular skeleton including two nodes. 
l.t., leaf-traces ; internal strand, which sends off a dorsal branch below 
each leaf-insertion. This dorsal branch splits into two (c., c.) which eventually 
help to close the leaf-gap. r., roots. From Kuhn. 
Kaulfussia differs from the types already described in having a 
creeping rhizome with definitely dorsiventral structure, bearing 
roots on its sides and lower surface, and two rows of leaves on the 
upper side. The vascular system (Fig. 76) consists of a much 
perforated solenostele 1 but in this case only the dorsal portion is 
Fig- 77. Kaulfussia ascnlifolia. A.—Vascular strands of base of petiole. 
B. — Lower part of petiole. C. — Upper part of petiole. Sec explanation of 
Fig. 72. From G wynne-Vaughan. 
concerned in the bearing of leaf-traces, and its meshes are much 
' If we define a dictyostele as possessing overlapping /tfo/"-gaps. 
