xxv] 



ANKYROPTERIS 



451 



are (i) the double anchor-like form of the H -shaped petiole 

 strand in which the lateral arms (antennae) are curved like the 

 flukes of an anchor, and (ii) the emission of four rows of branches 

 instead of two. The latter distinguishing feature no longer 

 holds good, as Z. privfiaria also gives off four rows of bundles 

 and not two as Stenzel supposed. P. Bertrand has adopted 

 Stenzel's genus in a narrower sense ^. 



Fig. 311. Ankyropteris Grayi. Stele. (From a section in Dr Kidston's 

 Collection, x 18.) 



Ankyropteris scandens StenzeP. Fig. 310, D. 



This Lower Permian species is very similar to or perhaps 

 identical with Ankyropteris Orayi (Williamson). The stem of 



1 Dr Scott points out to me that recent observationB, which have not yet 

 been published, both by Dr Kidston and himself show that Bertrand's 

 terminology requires modification. There are many points to be cleared up 

 before we can hope to obtain a satisfactory classification of the Zygoptereae. 



2 Stenzel (89) p. 31, Pis. vi. vii. 



