Further Notes on Floral Structur- 



es. 



87 



The first section cut is that of fig. 9 A, showing distinct 

 agreement of the staminate disk with the corresponding trans- 

 verse section from the flower of trunk 3 seen in figure 3, section 

 728, and in figure 3 B. And the meaning of the section was 

 further confirmed by a rigid search all over the surface of the 

 trunk, taken point by point, resulting in the detection of a 

 single additional example, clear of outline but previously over- 

 looked. This flower has not been cut from the trunk, where 

 it appears just as shown in figure 9 B. The synangia are 

 apparently larger than in trunk 3, which is realty yet another 

 reason for supposing the flower of that trunk to be not quite 

 fully grown. But caution in judging without thin sections is 

 required, here or in the case of any flower or strobilus, — more 



Fig. 9. 



Fig. 9. Cycadeoidea Marshiana. 



(For 



Two bisporangiate flower buds from trunk 164 of the Yale Collection, 

 figures of this trunk see American Fossil Cycads, Plate VIII et seq.) 



(A) Transverse thin section through the summit of a flower with nine 

 microsporophylls. The section passes at some distance above the ovulate 

 cone, and no decurved tips of microsporophylls appear at the center. En- 

 larged about twice. 



(B) Drawing of a portion of the surface of branch (C, Plate VIII, Ainer. 

 Fos. Cycads) snowing partly eroded flower bud. The mass of synangia and 

 pittings corresponding to the rachides of eleven microsporophylls plainly 

 appear. Shown in natural size. 



especially where but a few axes are studied. The number of 

 disk divisions is clearly eleven ; so that while the study of this 

 form still rests mainly on macroscopic features, there is little 

 doubt as to its identity. 



Probable Habitus of Cycadeoidea nana of Ward. 

 Figure 10. 



The subject of small cycad flowers and the branching habit 

 is further illustrated by the quintuply-branched trunk of fig. 

 10, consisting in a central stem, two large basal and two lesser 

 lateral branches. This exceedingly interesting specimen was 



