CTCABOPHTTA. 103 



Class CTCAD0PHTTA.1 



Section BENNETTITALES.^ 



In the second volume of the Wealden Flora (British Museum 

 Catalogue) an account was given of the history of our knowledge 

 of the genera WilUamsonia and Bennettites,^ and I expressed the 

 opinion that the fossils described by "Williamson under Camithers' 

 designation WilUamsonia are in all probability generically identical 

 with the reproductive shoots of Bennettites, as represented by 

 B. Gihsonianus, Carr. It is not proposed to traverse the same 

 ground again, but to draw attention to some more recent opinions 

 bearing on the nature of these interesting types of extinct 

 Cycadophyta. 



There has been considerable difference of opinion as to the 

 correctness of WUliamson's conclusions which he expressed in 

 a restoration of WilUamsonia ; * he brought forward evidence in 

 support of the view that the pinnate Cycadean fronds described 

 by Lindley & Hutton as Zamia gigas belong to the plants which 

 bore the reproductive shoots known as WilUamsonia. Saporta 

 believed that the leaves and reproductive organs had no connection 

 with one another, and Solms-Laubach demurred to the acceptance 

 of "Williamson's views without further evidence. In a paper 

 communicated to the Philosophical Society of Cambridge in 1897 ^ 

 I described some Yorkshire specimens of Zamites gigas and 

 WilUamsonia included in the Yates Collection in the Natural 

 History Museum, Paris, and expressed my conviction that these 

 specimens demonstrate the correctness of the statement that 

 WilUamsonia and Zamites gigas are the female inflorescences and 

 fronds of one and the same plant. In the volume on the Jurassic 

 Flora published in 1900 I again discussed the connection between 

 WilUamsonia and Bennettites, and spoke of them as two very 



1 Nathorst (02), p. 3. 



' Engler & Prantl (97), pp. 5, 341. 



' Seward (95), p. 134. 



^ ■Williamson (70). 



s Seward (97^). 



