486 



CYCADOPHYTA 



[CH. 



are broad but the cells are not preserved. The pith-cast is of 

 the usual Cycadean type. 



The type-specimen was presented by the Cirencester College 

 to the British Museum. 



Bucklandia buzzardensis (Stopes). 



This species, from Lower Greensand beds at Leighton Buzzard 

 and believed to be derived from Wealden strata, is described by 

 Dr Stopes 1 as Cycadeoidea buzzardensis. Though agreeing generally 



FIG. 578. Bucklandia buzzardensis. Rough sketch of a block of wood showing 

 parts of at least eight concentrically arranged rings of secondary wood. 

 (After Stopes; x f.) 



with B. Yatesii, the stem is specifically separated on the ground 

 that the petiole-bases are more expanded laterally and because 

 of the occurrence of several vascular cylinders (fig. 578), sometimes 

 as many as eight, each with a maximum diameter of 1 cm. 

 Dr Stopes thinks it possible that B. buzzardensis is an older form 

 of B. Yatesii. 



1 Stopes (15) p. 309, text-figs. 98100. 



