G. R. Wieland — Williamsonian Tribe. 



461 



(G) Williamsonia pecten N athorst. — (Small disk form.) 



" tuberculata and bltuberculala Nathorst. — Disk 



staniinately 15 — cleft. 

 Williamsonia mexicanus (Wieland MS.). — Disk pinnately 



+ 10— lobed. 

 Weltrichia (?) mirabilis Fr. Br. — Disk 15 — lobed. 

 (D) Williamsonia (?) Lignieri, Nathorst. — Small, whorled scale- 

 like stamens. 

 Wielandiella angustifolia Nathorst. — Disk or close-set 



whorls of small stamens. 

 Wielandiella punctata, Nathorst. — Disk or close whorls of 



minute nearly sessile stamens. 

 Williamsonia rajmahalensis (Wieland sp). — Short whorl of 

 (6 + ) small elongate staminate scales, or staminophylls. 



Fig. 17. 



D 



Fig. 17. Four types of Williamsonian pollen-bearing organs. A and B 

 are shown about half , and C and D nearly, the natural size. . _™ 



(A) Williamsonia tuberculata (Yorkshire coast). Restoration by Nathorst. 



(B) Williamsonia. spectabilis Nathorst. Pinnate and possibly unisexual 

 flower from Yorkshire coast as restored by Nathorst. 



(C) Williamsonia mexicana (Wieland MS.). Restoration of Mixteca Alta 

 (Mina Consuelo) disk in segment form. 



(D) Williamsonia (?) rajmahalensis (Wieland sp.). After Feistmantel's 

 figure of specimen from Bindrabun, Rajmahal Hills, India. Unisexual 

 whorl. Cf. reference 8, p. 131, and pi. xxxix, fig. 5, 5a. 



