430 



6r. E. Wieland — American Fossil Cycads. 



by these bands separated the adjacent loculi. On the inner 

 side of each row of loculi as thus delimited there is, finally, a 



Fig-uke 2. — Cycadeoidea dacotensis Macbride. Transverse section of adjacent 

 synangia. In the central synangium the outer covering of heavy walled pris- 

 matic cells is seen to be followed by a thin-walled layer. Adhering to this are 

 the sporangial loculi closely ranged on each side of the synangium in two rows. 

 Bach, loculus is delimited by bauds of collapsed cells with adhering pollen grains, 

 and each row of loculi is bounded on the inner side by well defined tissue a single 

 cell in thickness, except between the angles of adjacent loculi, where there is a 

 thickness of several cells. This layer thus bounds the two opposed inner faces 

 of the synangium. It is usually split on the median line of the sporangia, and 

 the striate appearance of its elongate cells when cut obliquely is indicated in 

 several instances. 



The tips of the three synangia on the left side of the figure are seen to be 

 oriented nearly at right angles to the others, being cut very obliquely. At the 

 lower left-hand corner portions of two transversely cut sporophylls are seen. 

 x 30. (Based on section figured in Part III of these studies, Plate X, figure 17. 



