_ to Washington. 
216 Dr. J. 8, Newberry on Ancient Vegetation of N. America. 
present. Unger has thus represented it, and Brongniart calls it 
a transition from the great Cycadaceous flora, of the Jurassic 
period, to the Angiospermous flora of the Tertiary. In Europe 
the Cretaceous flora was, apparently, more like that of the Lias 
and Oolite than in this country, for while the genera Salix, Acer, 
Populus, Alnus, Quercus, &c., were then introduced there as here, 
its general aspect was modified by the presence of numbers 
Cycadacec, and its sub-tropical character attested by fan-palms. 
We may find hereafter, in other parts of the continent than 
those in which I have examined the Cretaceous strata, fossils 
which shall assimilate our flora of that period more closely to 
that of Europe, but as far as at present, known, our plants 
this age present an ensemble quite different. I have now some 
sixty to seventy species of Cretaceous plants collected in New 
Jersey, and in various parts of the great Cretaceous area 0 the 
interior of the continent, all of which indicate a flora very sul 
ilar to that now occupying the same region ; many, perhaps most, 
of the genera being now represented in our forests—such as Li 
riodendron, Platanus, Acer, Populus, Salix, Alnus, Fagus, 
These specimens have been collected in localities included between 
the 36th and 41st parallels of latitude, but range from the 74th 
tothe 110th of longitude. Nowhere within this area have | ng 
any traces of palms or any indications of a trop! 
mate. At ithe base of the Yellow sandstone series of New Mex: 
ico, (Lower Cretaceous,) I have found a varied and interesting 
ora, containing Pterophyllum, Nilssonia, Camptopteris, &e. 
a few duaaeaee tsirigledebonh leaves. is is evidently the 
point of junction between the Cycadaceous flora of the #0 
age and that of the Chalk; for in the entire overlying Oselne 
strata, 4000 ft. in thickness, though Angiospermous len 
abundant, those of Gymnospermous plants were nowhere coke 
ered, nor any traces of palms, either leaves or stems. 6 
flora of 
North America I am mainly indebted to the kindness of Dr 
_ Hayden, who has spent several years in most successfully <—. 
ing the geology, botany and zoology of the country bord or 
Lio- 
the ney 
which desoriptions will be published immediately after my 705" 
a ‘ I 
with mé; 
I remem 
Not having the specimens, or my notes on them, 
‘speak only generally of the flora they represent. 
~— ecthate Shae: ink ies of Plaian 
closely resembles Unger’s great P. Herou 
ude species 0 Jes and is perbaP® , 
