Dr, J.S. Newberry on Ancient Vegetation of N. America, 213 
The species of your fossil plants are probably all new, though generally 
closely allied to the Cretaceous species of the Old World. From the 
limited study I have given them, I have referred them to the following 
genera : 
Sphenopteris, Cornus, Salix, 
bietites, Liriodendron, Magnolia? 
Acer. Pyrus ? Credneria, 
Fagu Alnus, ' | Ettingshausenia, 
Populus, 
_ Of these the last two are exclusively Cretaceous and- highly character- 
istic of that formation in Europe. 
For comparison with the preceding list of genera, I subjoin a catalogue 
of the Cretaceous genera found at Bl nkenburg in the duchy of Bruns- 
wick, given by Stiehler in the Paleontographica, Sept. 1857. 
Credneria, Pterophyllum, Comptonites, 
drites, Flabellaria, Populus 
Alge { Halymenites, Pinites, Alnites, 
» elessertites, Geinitzia, r. 
P< uisetum, Araucarites, Quercites, 
| Pecopteris, Salicites, Juglandites. 
i may say, in confirmation of the assertion that your fossil plants are 
fretaceous, that I found near the base of the Yellow Sandstone series in 
Mexi lled Jurassic by Marcou,—a very similar flora to that 
rep your specimens, one species at least being identical with 
yours—associated with Inoceramus, Gryphea, and Ammonites, of Lower 
es. ours, &e., 
8. Newserry. 
Since that letter was written, I have added largely to my ma- 
terial illustrative of the American Cretaceous fauna and flora, 
having been for some months engaged in studying that forma- 
lion over a large area, and where it exhibits an unequalled de- 
ie the geological age of the deposits which contain the fossil 
es 
be the slightest doubt. I have in my hands over sixty species of 
in New Jersey, Nebraska, Eastern, Middle and Wester 
agg New Mexico and Utah, collected by Prof. Cook, Mr 
ren Hayden and myself. of the species are common 
nearly all the exposures of the Lower Cretaceous sandstones, 
hich Thave examined, verywhere serve for the accurate 
- tormable and undi both Dr. Hayden and myself have, 
le pate erage or of the most characteristic fos- 
of the chalk, such as Gryphcea Pitcheri, Inoceramus problem- 
\ 
