442 COENOPTERIDEAE [CH. 



Botryopteris antiqua, Kidst. Fig. 307. 



This species, recently described by Kidston^ from the Culm 

 of Pettycur near Burntisland, is represented by sections of a 

 small stem with a cylindrical stele 0"40 mm. in diameter com- 

 posed entirely of scalariform tracheae without any recognisable 

 protoxylem. The petioles are larger than the stem; the 

 meristele (fig. 307) is oval with protoxylem elements on the 

 slightly more rounded adaxial face. As Kidston suggests, this 



Fig. .307. Botryopteris antiqua : Petiolar vascular strand. (After Kidston: x 65. ) 



stem may belong to a scrambling plant which required support 

 to bear its relatively large leaves. An interesting feature is 

 the absence of projecting teeth in the leaf-trace, a character in 

 marked contrast to the ea form assumed by the petioles of 

 Botryopteris forensic (fig. 319, G) and B. hirsuta. This leads 

 Kidston to suggest that the vascular strand of the petiole 

 tends "to become more simple... as traced back in geological 

 time." The greater similarity in this species between the stele 



1 Kidston (08). 



