84 G. R. Wieland — American Fossil Cycads. 



ding and sporangial collapse having occurred. The seeds show 

 but little structure, being distinctly younger than those of fig- 

 ure 6, already mentioned as showing testal zones and distinct 

 nu cellar sacks. 



Cell walls are however generally obscure : one cannot make 

 out the bract structure; and similarly the disk and rachides, 

 though very clearly outlined, appear only as an indistinctly 

 granular groundmass traversed by lighter colored traces of the 

 bundles, fortunately continuous enough to show the pattern 

 of the bundle system. But even so the assemblage of fairly 

 well-conserved features taken together with the entire outline 

 of all organs affords a clear view of the form and general 

 structure of the flower. 



On noting that seven rachides are to be seen in sections 726 

 and 728, and then comparing the series of decurved apices in 

 section 761, figure 3a, it becomes evident that the disk divides 

 into twelve small microsporophylls as in the young and quite 

 small flower of Cycadella ivyomingensis (American Fossil 

 Cycads, figure 93 I) and the very large flowered C. ingens of 

 the columnar series, instead of dividing into seventeen or 

 eighteen large staminate fronds as in C. dacotensis and various 

 of the Williamsonia staminate disks or flowers. The point at 

 which the campanula splits into the separate fronds is accu- 

 rately located between sections 715 and 728, figure 3, at a 

 hight of about a centimeter above the apex of the ovulate cone, 

 which is not a precisely fixable point because ending as a long 

 thin brush of sterile organs at last almost hair-like. 



The length of the microsporophylls can only be estimated 

 within fairly close limits because of the destruction of the 

 mid-region of the bud summit by erosion ; but estimating this 

 loss at about one centimeter and adding for the decurved tips 

 1*5 centimeters, the full length of the microsporophylls appears 

 to have been about 5 # 5 centimeters. Whence after allowing 

 for the diameter of the ovulate cone, the flower as imagined 

 in an arbitrarily expanded form would have a diameter of ten 

 or twelve centimeters. 



The rachis and pinnules, as one readily sees in the longitu- 

 dinal section fig. 2B and the transverse section fig. 3 A, are 

 much moulded and furrowed by appression faces or even crin- 

 kled, but withal in a manner producing ornate patterns where 

 these organs are cut to advantage in regular series. The pin- 

 nules are broad of base and must tend to confluence with each 

 other. They are a centimeter long in the mid-rachidal region 

 and dimiuish much in length towards both base and apex of 

 the frond ; so that each frond if laid out flat would have a 

 more or less elongate-elliptical acuminately tipped, pinnately 

 parted to pinnately divided form. 



