212 Dr. J. 8. Newberry on Ancient Vegetation of N. America. 
based, I enclose a copy of my letter to Messrs. Meek and Hay: 
den, which I chance to have with me. i 
Washington, D. C., Nov, 12th, 1858. 
Messrs. Merk and Haypen, - 
Gents: The fossil plants which you requested me to examine, Thaw — 
looked over with great pleasure, and, in answer to your question ast) 
the age of the strata from which they were derived, concur with youin — 
the opinion that they belong to the Cretaceous epoch. They include, 
however, so many highly organized plants, that were there not among 
them genera exclusively Cretaceous, I should be disposed to refer them 
to a more recent era. = 
A single glance is sufficient to satisfy any one that they are not Ti- | 
assic. Up to the present time no angiosperm dicotyledonous plants hare 
been found in rocks older than the chalk, while of the eighteen specs 
which compose your collection sixteen are of this character. . 
at was the general aspect of the flora of our Cretaceous eontinent 
we can only conjecture, as the specimens of it which we have, represett : 
only its ruder and coarser elements,—the leaves of some of its Adi . 
trees, which, perhaps by an annual frost, were, as now im pom eo ; 
tered on the surface of stream, lake, or sea, and, sinking, ming a 
the sediment accumulating at the bottom. the relic : 
In such an herbarium we could expect to find little else than ‘ole | 
of some of the ligneous plants, and a very imperfect picture of a 
of the period. je 
The evidence furnished by your specimens is, however, good as ‘oft 
it goes, and we are warranted in inferring from them the rie? aa 
more highly organized flora during the Cretaceous perl than 
ally been attributed to it. Toga aaa dicots! 
A flora so highly organized, embracing so many AOR et have at 
edonous plants, should lead us to expect the discovery of ‘Wi 
burst into being, but was doubtless preceded in the older pee 
followed them. : collections i 
' From the enumeration of the genera represented in your very wall 
will be seen that the flora of the Cretaceous epoch was we ph 
that of the temperate portions of our continent at the pan Upper Mis 
same thing may be said of the Miocene Tertiary flora of x“ poth the 
souri so fully illustrated in the collections of Dr. Hayden. the same Pe 
tropical and sub-tropical forms so common in the floras ter relative UF 
riod in Europe, are apparently wanting; indicating a ee carrying tb? 
formity of due during the later geological epochs, | "Thus it ma hes 
aspects of nature of the present, far back into the past. old-is 
said of our plants as of our fishes, that many of the 
joned” types. : > allude, is* 
An interesting fact in this connection, to which I can only 1 Up Noth 
the later extinct floras of Europe are more like the exe ntain he ; 
America, than is that now growing over the rocks which ; ae re 
7 Including as they do Liguidambar, Liriodendron, &., now exclusivey 
