XXXVI] CYCADEOIDEA 369 



Zeiller^ also include the small globular stems named by Saporta 

 Bulbopodium in the older genus Cycadeoidea : one such type from 

 the Portlandian of Boulogne is described by these authors as 

 Cycadeoidea pumila. Saporta also proposed the name Platylepis^, 

 the type-species being Cycadeoidea micromyela Mor., from the 

 Lias of Calvados, which has recently been investigated by Lignier^ 

 who wisely adopts Moriere's designation. Another unnecessary 

 generic name is Schizopodium given by Moriere to a stem, S. 

 Renaulti*, regarded by Lignier as indistinguishable specifically 

 from C. micromyela. 



The two names Cycadeoidea and Bennettites have been used 

 by authors for stems which are unquestionably generically 

 identical and as is often the case much confusion has been caused 

 through the failure of palaeobotanists to arrive at an agreement. 

 Lester Ward, a staunch advocate of the rule of priority, repeatedly 

 pointed out that Buckland's name Cycadeoidea should take 

 precedence of Bennettites on the ground that stems for which 

 these genera were instituted are clearly of the same type, and he 

 added that the older genus, though abandoned by its author, 

 cannot be given up without violating the inexorable rules of 

 priority. On the other hand it has been urged that the genus 

 Bennettites as defined by Carruthers is characterised by the 

 possession of (i) fertile shoots bearing strobiU and (ii) vegetative 

 organs exhibiting certain anatomical characters. Buckland's 

 species of Cycadeoidea, though bearing lateral shoots, are not well 

 enough preserved to afford definite information as to the morpho- 

 logical features of the strobih, nor have we satisfactory data 

 with regard to the degree of resemblance between the vegetative 

 features of Bennettites and the Portland stems. Carruthers laid 

 stress on the elHptical section of the stele in Bennettites in contrast 

 to the cyhndrical cyhnder of Buckland's Cycadeoidea trunks. 

 Subsequent research has shown that this difEerence is not in itself 

 a vahd criterion either of generic or specific rank but, as Wieland 

 says, it is an open question to what extent the stem structure of 

 Cycadeoidea and Bennettites agrees. The probabihty is that were 

 our knowledge of the Portland stems less incomplete, they would 



1 FHohe and ZeiUer (04). ^ Saporta (75) A. p. 276, PI. 120. 



3 Lignier (01). * Ibid. (13) p. 93. 



S. m 24 



