188 



■SVItLIAMSONIA. 



Portions of two other peduncles occur on the same piece of 

 Tock ; also a very good specimen of a WilUamsonia ' head ' or 

 flower. The flower shows the central pyriform and tapering 

 cavity surrounded at the base by the characteristic zone marked 

 by radiating lines, and enclosed by numerous linear bracts. The 

 specimen is practically identical with that represented in pi. lii. 

 fig. 6 of Williamson's Memoir.' 



Several pieces of fronds occur in association with the peduncle 

 and flower. 



In Text -fig. 29 we have a sketch of the broken end of the 

 axis of the peduncle, shown in Fig. 1, PI. VII., as seen in 

 lookiug upwards along the cavity left on the removal of the 



Fig. 29. — WilUamsonia gigas (L. & H.). View of the tnincated end of the 

 peduncle shown in PI. VII. Fig. 1. No. 46,633. ( x Ij.) 



lower part of the peduncle. In the upper portion (c in Fig. 1, 

 PI. YII.) the axis itself has been preserved, and the truncated 

 end is shown in the Text-figure ; the axial portion is elliptical 

 in shape, and is surrounded by the linear scale-leaves, which in 

 Fig. 1 are seen in surface -view ; these bracts are represented in 

 the Text-figure by somewhat crushed shells of hypodermal tissue 

 •enclosing spaces bounded on the outside by convex walls, and 

 internally, where the bracts are in contact with the axis, by more 

 ■or less straight walls, as shown in the upper part of the figure. 



38,785. PL VIII. Fig. 1, and 38,784. 



These two specimens, one the reverse of the other, illustrate 

 the form of an unusually large example of that part of the fioral 

 organ which Williamson named the carpellary disc ; the same 



' ■Williamson (70). 



