Dr. J. 8. Newberry on Ancient Vegetation of N. America. 217 
as large; Populus, Acer, Castanea, Sapindus, Carpinus, Ulmus, 
Diospyros, Quercus, Salix, Taxodiwm, and others which indicate a 
flora in all its general aspects similar to that now occupying the 
Valley of the Mississippi. A few plants in the collection would 
seem to have required a somewhat warmer climate than that 
which the localities where they are found enjoy at present; but 
there are no palms among them, nor any of the tropical genera 
Cinamomum, Sterculia, Dombeyopsis, &c., so common in the Ter- 
tiary strata of Europe 
Cinamomum, &¢., which indicate, at least a sub-tropical climate ; 
_ &flora quite unlike that from the Miocene of the Upper Missouri, 
: although, as he remarks, similar to that of the Miocene of Europe. 
; am tempted to dwell for a moment on the interesting glimp- 
ss of the physical geography of our continent in geological times, 
which these facts and others that have come under my observa- 
ion afford ; for, to you, who have done so much toward the elu- 
cidation of its geological history, this cannot, I am sure, be a mat- 
of indifference, but my letier has already grown to an unrea- 
sonable length. Let me then close with a few generalizations, 
“tring you to my reports for all details of fact sustaining them. 
Ist. A large continental area occupied the place of the interior 
of North America from the earliest Palzeozoic ages 
2d. During the Carboniferous epoch this land sustained a veg- 
on similar to that of the Coal period of Europe and Eastern 
: America, though far less varied. 
| 8. Through the Triassic and Jurassic ages the sediments from 
4 preponderance of Cycad lants, analogous to those of the 
Jurassic of Bare ycadaceous p ) g 
, ith. In the Cretaceous age, the central nucleus of the con- 
nt was sufficiently extensive to furnish from its ruins arena- 
matter, mainly derived from the land plants which covered the 
Continent. Ag far south as lat. 35° these plants were for the 
an part Coniferous or Angiospermous, an included many gen- 
_ “| bow characteristic of temperate climates. 
and Tough the Tertiary eppiencintt continent had nearly the form 
~~ *fea it now has, the Tertiary deposits merely skirting its 
* XvVii, Zi, 861. 
“=conp ‘aed Vor. XXIX, No. sig ad ag 1960. 
