182 WILLIA.MSONIA. 



fronds of Zamites gigas as the leaves of the plant which bore 

 a Williamsonian inflorescence. 



One not infrequently finds a small hud or young Williamsonia 

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

 5 cm. broad. The peduncle 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. A peduncle of this kind is figured by Saporta in pi. xv. 

 of vol. iv. 1 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 

 opportunity afforded me of examining the fossils figured in 

 Professor Williamson's valuable memoir. 



Saporta alludes to the resemblance of the peduncle which he 

 figures to the stem of Zamites gigas,- represented in his volume 

 on Cycads (pi. xi. fig. 1), but he does not regard the similarity as- 

 evidence of relationship or identity. This specimen of Zamites 

 referred to in the above quotation, from the second volume of the 

 Plantes Jurassiques, is of exceptional interest and furnishes the most 

 important link in the argument in favour of the connection between 

 Williamsonia and Zamites gigas. Saporta' s figure is very imperfect, 

 and conveys but a poor and erroneous idea of the actual specimen. 

 In the lower part of the figure is shown a stem about 5 cm. 

 broad, with the surface features indistinctly preserved, but showing 

 a number of imperfect scale-leaves. To one side of the stem, 5 cm., 

 from the bottom of the specimen, are attached the petioles of two 

 clearly preserved fronds of Zamites gigas, and above these occurs 

 part of a third frond apparently in its natural position but without 

 the petiolar attachment. The stem is prolonged obliquely upwards- 

 to the left in the form of a branch about 3 cm. broad and 14 cm. 

 long. This branch is thickly clothed with hairy leaf-scales, and 

 terminates in numerous spreading leaf-scales of a narrow linear 

 lanceolate form. The position and surface features of this branch 



1 Saporta (91). 



2 Saporta (75), p. 55. 



