1897.] Mr Seward, On the leaves of Bennettites. 275 



unusually fine collection of English Williamsonias from the late Mr 

 Yates. These specimens are now in the Natural History Museum, 

 Paris, and many of them were drawn for Brongniart with a view to 

 publication, but the work was unfortunately never completed. The 

 drawings were afterwards made use of by Saporta in his compre- 

 hensive work on Jurassic plants. In describing the Yates specimens 

 Saporta expresses himself strongly against the generally accepted 

 view as to the union of Williamsonia and Zamites. He does not 

 hesitate to separate the Zamites fronds from any connection with 

 the Williamsonias. There is he admits " une certaine conformite 

 apparente entre les appareils floraux auxquels on peut laisser le 

 nom de Williamsonia et le Zamites gigas, tel que le fait voir le 

 remarquable empreinte de la collection du Museum de Paris (voy. 

 PI. 81, fig. 1). Nous avons tout bien de considerer les Williamsonia 

 corame representant l'inflorescence d'une monocotyle'done primi- 

 tive, revelant un type de Pandanees plus ou moins analogue aux 

 Yuccites, aux Podocarya, aux Eolirion de Andrae, etc. 1 " 



It is unnecessary to quote the various views advanced by 

 different writers as the botanical affinity of Williamsonia, especially 

 as these were in many cases largely influenced by Saporta's 

 decision as to the complete independence of this genus and Zamites 

 gigas. Nathorst proposed a comparison of Williamsonia with the 

 Balanophoreae' 2 , but afterwards 3 reverted to the opinion of the 

 earlier writers as to its connection with Zamites. 



A recent examination of the Yates collection in Paris, and 

 a comparison of the numerous specimens in the museums of 

 London, Cambridge, Whitby and Scarborough has led me without 

 hesitation to regard the pinnate Cycadean fronds of Zamites 

 gigas as the leaves of the plant which bore a Williamsonian 

 inflorescence. 



One not infrequently finds a small bud or young Williamsonia 

 borne on the end of a peduncle about 20 or 30 cm. long and 3 to 

 5 cm. broad. Such an axis is covered with linear lanceolate scale 

 leaves spirally disposed and often clothed with delicate hair-like 

 ramenta, such as occur on the scale leaves of Dioon and other 

 recent Cycads. Such a peduncle is figured by Saporta on PI. XV. 

 of Vol. iv. 4 The original is in the Paris Museum ; the scale leaves 

 are less prominent and not so thick as those shown in the drawing, 

 and in this and other specimens one sees traces of the ramental 

 appendages. The best example of a peduncle is included in the 

 series of specimens of Williamsonia now in the possession of 

 Mrs Crawford Williamson, to whom my thanks are due for an 



1 Pal. Frang. Plantes Jurassiques, Vol. n. 1875, p. 55. 



2 Ofr. k. Vet.-Akad. Forh. 1880, No. 9, p. 33. 



3 Ibid. 1888, No. 6, p. 359. 



4 Pal. Frang. Plant. Jurass. Vol. iv. 1891. 



VOL. IX. PT. V. 22 



