G. R. Wieland — Cycadeoidean Flower-hud Structure. 131 



by Oliver,* the internment even rises free from the nucelkis 

 before dividing into the canopy and the thin lagenostome 

 extension which as in Sphgerostoma wholly lacks the special- 

 ization into the distinct regions so marked in Zagenostoma and 

 Conostoma. 



In order to give more precision to discussion and descrip- 

 tion of the complex testal forms of Paleozoic time, Oliver and 



Fig. 8. 



Fig. 9. 



Figures 8, 9. Sphcerostoma ovale Benson, a seed about four millimeters 

 in length from the Lower Carboniferous of Scotland. 



Fig. 8. Longitudinal section of seed and enclosing cupule. From 

 Benson. 



/, 



frill 



P, 



plinth 



c, 



cupule 



a, 



archegonium 



ca, 



canopy 



es, 



embryo-sac 



si, 



sinus 



vbi, 



integument bundle 



pc, 



pollen chamber 



ab, 



abscission layer 



n, 



column 



l't>2, 



cupule bundle 



w, 



lagenostome 



vb 3 , 



ovule bundle 



Fig. 9. Frill region of seed with hypothetical position (L) of lageno- 

 stome. Modified from Benson. 



Sclerotic sheath in solid black ; vb, extreme apex of one of the eight 

 integumental bundles ; aq, aqueous tissue ; D, continuation of epi- 

 dermal secretory cells. 



* Ann. Bot., vol. xxiii, No. lxxxix, Jan., 1909 (cf. p. 92, 



7). 



