PLATE XXIX. 



Page. 



Figs. 1-4. Populus rotundif olia Newb 51 



5. Populus smilacifolia Newb ___.. __„i.__ 53 



6. Populus cordata Newb 38 



7. Populus cuneata Newb _ 41 



8-10. Cory his Americana f ossilis Newb . _ 60 



212 



