XXXVII] 



WILLIAMSONIA 



431 



preservation of the sterile zone of armour which formed a cluster 

 of appendages, the impressions of which are seen on the sides of 

 the funnel-like depression, the receptacle being prolonged as a 

 slender axis (fig. 547, C). The next point to consider is the form 

 of the axis beyond the level of the collar of sterile armour. 



c 



FIG. 547. Williamsonia gigas. A, flower in longitudinal section, showing, 

 especially on the left side, interseminal scales and megasporophylls and 

 a pyriform cavity representing the central axis (nat. size). A', the under 

 surface of the apical region. A", interseminal scales from A'. B, cast 

 of A'. C, apical region of another specimen; a, interseminal scales ; c, column; 

 r, ridge. (Williamson Collection, Botany School, Cambridge.) 



Williamson described the axis as spreading out to form the lenti- 

 cular disc and then prolonged as a narrow conical pyramidal 

 axis which is slightly extended horizontally immediately below 

 a terminal mammilla : the apical mammilla he designated the 



