WILLIAMSONIA. 177 



Fanuly BENNETTITE^. 



Under this head we include the genus WilUamsonia, which 

 may be conveniently retained as a Mesozoic type closely allied 

 to Bennettites. There appears to be good evidence also in favour 

 of including the genus Anomo%amites in the Bennettitese. In 

 the second volume of the Wealden Catalogue ' I have used 

 WilUamsonia in the sense of a subgenus of Bennettites, and it 

 is possible that this is the wiser course to adopt ; on the other 

 hand, we are less intimately acquainted with the plants usually 

 referred to WilUamsonia than with the original species of Bennettites, 

 and it is a convenience to retain the former name as denoting 

 a member of the Bennettitese which has long been known as 

 a Jurassic genus of doubtful affinity. 



Genus WILLIAMSONIA, Carmthers. 

 [Trans. Linn. Soc. vol. xxvi. p. 691, 1870.] 



1. Williamsouia gigas (Lindley & Hutton). 



2. Williamsonia pecten (Phillips). 



The history of WilUamsonia was dealt with at length in the second 

 volume of the Wealden Catalogue, and need not be recapitulated.^ 

 Since my account of WilUamsonia was written I have had an 

 opportunity of examining several specimens of the genus, and from 

 some of them, more particularly from English examples in the 

 Ifatural History Museum, Paris, I have been able to satisfy 

 myself that "WilUamson's restoration of the Yorkshire Oolite 

 plant " — Williamsonia gigas — is in essentials correct. The 

 pinnate Cycadean fronds described in 1835 as Zamia gigas were 

 undoubtedly borne on a stem which presented an appearance 

 practically identical with that of most recent Cyoads ; the same 

 stem also bore flowering shoots which terminated in flowers 



' Seward (95), p. 146. 



2 Seward (95), pp. 146-157. 



^ 'Williamson (70), pi. liii. 



