392 



BENNBTTITALES 



[CH. 



certain recent Flowering plants; it is one of the distinguishing 

 features between Gymdeoidea and stems bearing longer fertile 

 shoots with flowers of the Williamsonia type. 



Fio. 521. Cycadeoidea (Bennettites) Gibsoniana. A, C, longitudinal sections; 

 a, absciss-layer ; b, bracts ; pr, ' pericarp ' ; s, scales, sterile and fertile. 

 B, transverse section of female flower; i, interseminal scales; m, megasporo- 

 phyUs. D, transverse section of seed showing the testa, t, separated by a 

 space, sp, from the embryo. E, embryo; r, radicle. (A, B. h, E, after 

 Solms-Laubach; C, section in the British Museum.) 



Fig. 517, C, shows a tangentially cut surface of a portion of 

 the stem of Cycadeoidea Gibsoniana with two axillary fertile shoots ; 

 one, 1, is cut across below the receptacle and shows the axis 

 surroimded by bracts while the other, 2, is seen at a higher level, 

 above the receptacle, where the section has exposed the numerous 



