26 



COENOPTERIDACEAE 



[CH. 



C/epsyo/ropsis. 



Z. iVi//iamsoni . 



Fig. 325. Diagrammatic comparison of tlie various types of Zygopteridean leaf-trace. 

 (After Kidston and Gwynne-Vaughan.) {Trans. Kov- Soc. Edin. vol. xlvii, p. 472.) 

 For a detailed description see text. 



hy ic 



€C oc' oc" 



Fig. 326. Ankyroptcris ivcstphalensis. Transverse section of a 

 petiole, showing the double-anchor form of stele, x, middle band 

 of stele ("a-polar"); x' , the main lateral bands ("antennae"); x" , 

 the small-celled external arcs of xylem ("filaments"); the proto- 

 xylem lies between x' and x" \ i.e., inner cortex; hy, sclerenchy- 

 matous hypoderma. ( x 7.) From a photograph by Mr L. A. 

 Boodle. S. Coll. 914. (After Scott.) 



