Further Notes on Floral Structures. 



85 



The synangia are well enough advanced in growth to outline 

 themselves distinctly, being in reality better conserved than 

 one might expect from the condition of some of the other tis- 

 sues. But the individual sporangia cannot be clearly made 

 out, and no distinct pollen appears. Inasmuch, therefore, as 

 the synangia have only from half to two-thirds the size seen in 

 C. dacotensis buds, in which the size agrees with that of Marat- 

 tiaceous synangial types, either a somewhat young stage of 

 growth is indicated, or as is more likely, an incompletely devel- 

 oped stage due to some failure in floral growth such as would 

 readily have been produced by events leading up to fossil- 

 ization. 



Fig. 7. 



^ X2S 



T.3.S. 75 L 



Fig. 7. Cycadeoidea Marshiana. Yale trunk No. 3. 



S. 756. Kamentum in transverse section, — study suggested for use in 

 determining species. The area shown includes the line // separating the 

 larger leaf-base ramenta from the small bract ramenta. In both cases the 

 hairs are characteristically one cell thick, except that occasionally the leaf- 

 base ramental scales are thicker. [Compare with Bennettites Gibsonianus.~\ 



S. 730. Transverse section through core containing two ovulate cones 

 which have shed their staminate disks. The section traverses the outer 

 armor, and cuts through the ovulate cone of the upper axis, but passes above 

 that of the lower. At Ms the saw cut for the longitudinal section 728 shown 

 in figure 2 A, q. v. Natural size. 



On the other hand, the possibility that the synangia like the 

 flowers were of small size, and the pollen all shed, should not 

 be lost sight of ; and as bearing on this point the supplement- 

 ary section No. 717 was cut in order to better bring out the fact 

 that the disk bears the same appearance of wilting and dehis- 

 cing just above the insertion as in G. dacotensis buds, where an 

 approach to floral maturity is seemingly indicated. 



But in neither case is it necessary to assume that the stam- 

 inate frond was normally of much larger size than here seen ; 

 while the ovulate zone is already notably older than in the 

 0. dacotensis buds, it even being possible that the mature stro- 

 bilus of trunk 3 did not reach a markedly greater size than in 



