370 BENNETTITALES [CH. 



be found to possess no anatomical features inconsistent with this 

 generic union. Granting the correctness of this view, the adoption 

 of the later generic term would be a reasonable course to follow 

 on the ground that it stands for stems showing well preserved 

 structure, while Cycadeoidea was in the first instance applied to 

 stems showing only partially preserved stumps of strobili, and the 

 name was not retained by its author. Graf Solms-Laubach 1 

 and some other authors have used Bennettites for Cycadean stems 

 possessing strobili of known structure such as those of Bennettites 

 Gibsonianus, reserving Cycadeoidea for similar stems but without 

 strobili sufficiently well preserved to afford evidence of morpho- 

 logical characters. This practice I followed in 1895 2 , but my 

 usage of the two generic names has not been consistent, the name 

 Cycadeoidea being afterwards employed 3 in a more comprehensive 

 sense. The investigation of the reproductive shoots of American 

 Lower Cretaceous and Upper Jurassic Cycadean stems 4 has 

 demonstrated the practical identity of their ovulate strobili with 

 those of the English Bennettites. It is clear that the American 

 stems as well as numerous specimens from Italy and other Euro- 

 pean localities are generically inseparable from Bennettites. The 

 adoption of Cycadeoidea by Wieland, following Ward, has naturally 

 strengthened the claim of Buckland's genus at least so far as 

 wide usage is concerned, and with some reluctance I propose 

 to fall in with this terminology and for the sake of convenience to 

 give up the use of Bennettites. Among Mesozoic Cycadean stems 

 agreeing with those of recent genera in habit and in the presence 

 of an armour of persistent leaf-bases are several which afford 

 no evidence either of the occurrence of fertile shoots or of lateral 

 shoots with terminal flowers. To such stems the name Cycadeoidea 

 has been applied, the designation Bennettites being restricted to 

 stems with lateral fertile shoots: this practice of treating the 

 absence of reproductive shoots as a characteristic feature of 

 Cycadeoidea is regarded by Wieland as illogical and artificial ; and 

 if, as seems probable, he is correct in believing that the majority 

 of the Mesozoic Cycadean plants culminated their vegetative 

 period by prolific development of flowers, the absence of flowering 



1 Solms-Laubach (91). 2 Seward (95) A. p. 139. 



3 Ibid. (04) B. p. 44. 4 Wieland (06). 



