44(1 



G. 



Widand — Will 'lam soman Tribe. 



Aside from these meager results in the field, which, except 

 for the proof of the occurrence of the small, much branched 

 and quite certainly plastic types like Wielandiella, really go 

 no further than to show the presence of just the surface details 

 one would expect to find, one step further can, however, be 

 made. It is now possible to add a most important inference as 

 to the possible nature and variety of William soman stem struc- 

 ture. It will be recalled that the Gondwana stem just men- 



Fig. 4. 



A B C 



Fig. 4. Williamsonian stem types of the characteristic form always found 

 most closely associated with the Williamsonia fruits of the Yorkshire and 

 Scottish coasts, India, and Mexico, and hitherto supposed to indicate more 

 Cycas-like forms, with carpellary leaves. 



n, n, the Wielandiel la-like nodes of leaf-base scars, the vertically elongate 

 intervening scars supposedly being those of scale-leaves. Cf. fig. 1, which 

 appears to be of different type rather than a huge peduncle or fruit-bearing 

 stem. 



(A) Bucklandia Milleriana Can - , x 3/10. Brora, Sutherlandshire, Scot- 

 land. From Carruthers (5). 



(B) Bucklandia (Yatesia) Joassiana (Carr.). x 3/10. Brora, Sutherland- 

 shire, Scotland. From Carruthers (5). 



(C) Williamsonia sp. x 3/5. Typical stem from the Bio Consuelo, Oaxaca, 

 Mexico. 



[All of these stems have been observed to branch dichotomously like 

 Wielandiella. They differ distinctly from Fittonia, which is a Cycadeoidea. 



tioned as having Ptilophyllum cutchense leaves attached has, 

 as figured by Seward,* a decidedly heavy wood zone marked 

 by a certain appearance or simulation of seasonal wood, and 

 also that the writer in his American Fossil Cycads (PI. XIV) 

 gave a photographic representation of a Black Hills Cycade- 



* Seward, A. C, Catalogue of Mesozoic Flants in the British Museum, 

 Part I, the Jurassic Flora of the Yorkshire Coast. Page 194, fig. 30. [Old- 

 ham and Morris also mention such Indian stems as silicified.] 



