G. R. Wieland — William sonian Tribe. 



443 



the other cycadophytean frond-yielding localities of the globe 

 (cf. Map, fig. 1) in 'most of which it is rather to be expected 

 that the Williamsonian fruits remain to be collected. Whence 

 the evidence from the side of the fruits precisely bears out that 

 from the stems. 



And that the inference just reached is valid, is further 

 attested by some of the lesser results of the field work of the 

 past ten years. Thus Nathorst and Halle on the Yorkshire coast, 



Fig. 5. 



Fig. 5. Foliage types of Williamsonias. 



A. Williamsonia gigas. x 1/5. Superior surface of frond showing ob- 

 lique insertion of pinnules with upper and basal angles free. Also portion 

 of frond of the pygmic species W. pecten (Phillips). 



B. Pterophyllum sp. Trias of Guilford, Conn. Frond type with linear 

 insertion of pinnules near midline. Slightly reduced. 



and the writer in the Mixteca Alta, have added perhaps a dozen 

 species to the Williamsonia ovulate cone series, and shown 

 the immense fossil wealth of the new quarries located in both 

 regions ; though as we see true Cycadacese remain quite as 

 scarce as before. In fact it lends no little emphasis to observe 

 that amongst all the Williamsonia collections made in Oaxaca, 

 there occurs just one single group of carpellary leaves, poorly 

 conserved, but with the medium sized seeds plainly indicating 



