XXXVI] CYCADEOIDEA 395 



of the epidermal layer which marks the boundary of the polygonal 

 areas. The structure of the megasporophylls and scales is more 

 fully described in the case of Cycadeoidea (Bennettites) Morierei 1 . 



The flowers of Cycadeoidea Gibsoniana appear to be unisexual 

 and ovulate : in view of the discovery by Wieland of numerous 

 bisexual fertile shoots on American species of Cycadeoidea it 

 would be reasonable to regard the apparently unisexual flowers of 

 the English species as originally bisexual but preserved at a stage 

 subsequent to the loss, by abscission, of the disc of microsporo- 

 phylls. Fig. 514 shows a flower of an American Cycadeoidea 

 practically identical with those of C. Gibsoniana, but the remains 

 of the staminate disc are clearly seen at d below the swollen apex of 

 the flowering axis. In the photograph of half of the same region 

 in C. Gibsoniana reproduced in fig. 522 there is no indication of 

 any similar trace of a whorl of microsporophylls. Admitting 

 the fact that a shrivelled remnant of the persistent base of a whorl 

 of microsporophylls might easily escape observation, it is difficult 

 to believe that any fertile leaves ever existed in the flower repre- 

 sented in figs. 521, 522. It is equally difficult to regard the 

 specimen represented in fig. 561 as other than a true unisexual 

 (ovulate) flower. 



Cycadeoidea (Bennettites) Morierei (Saporta and Marion). 



The name Bennettites was adopted by Lignier for this species 

 which was founded on a detached flower from the Gault 2 of 

 Vaches-Noires, Normandy. It was first described by Mori ere 3 , then 

 by Saporta and Marion 4 , who named it Williamsonia Morierei, and 

 it has since been thoroughly investigated by Lignier 5 . There is no 

 evidence as to the nature of the parent-stem though Mori ere 

 suggested a possible connexion with Zamia Brongniarti Mor. 

 (figured by Saporta 6 as Fittonia Brongniarti) from the same locality. 

 There can be no reasonable doubt that Bennettites Morierei was 

 borne on a lateral branch of a stem of the Cycadeoidea type : 



1 See page 396. 



2 The age was at first believed to be Oxfordian, but Lignier subsequently (09) 

 referred the rocks to a Lower Cretaceous horizon. 



3 Moriere (69). 



4 Saporta and Marion (81) A.; (85) p. 244; Saporta (91) p. 168, Pis. 148, 149. 

 6 Lignier (94 2 ); (04); (09); (11). " 6 Saporta (75) A. p. 328, PI. 123. 



