Mesozoic and Cenozoic Geology and Paleontology. 107 
where the beds have an estimated thickness of 5,000 feet, Diceratheri- 
um armatum, D. nanum, Thinohyus lentus, and 7. socialis. 
T. A. Conrad* described, from the Eocene at Wilmington, North 
Carolina, Terebratula demissirostra; and from Beaufort, Pecten ani- 
sopleura and P. carolinensis. | 
From the Miocene near Wilmington, and other places in North Car- 
olina, Liropecten carolinensis, Ostrea perlirata, Placunomia fragosa, 
Raeta alta, R. erecta, Abra bella, A. holmesi, Noetia protexta, N. filosa, 
Mercenaria carolinensis, Leptothyris parilis, Trachycardium bellum, 
Mysia carolinensis, Saxicava protecta, Turritella perexilis, 7. carolin- 
ensis, Fissurella carolinensis, Littorina carolinensis, Busycon kerri, B. 
amoenum, and B. concinnum; from Suffolk, Va., Zizyphus virginicus. 
W.H. Dalit described, from the Miocene at Cerros Island, California, 
Waldheimia.kennedyi; trom the Pliocene at San Diego, Chrysodomus 
diegoensis. And R.C.Stearns{ described, from the same strata, Opalia 
anomala, and O. varicostata. 
In 1876, Prof. J. W. Powell§ subdivided the Tertiary rocks of the 
plateau province of the west in ascending order, into the “ Bitter Creek 
Group,” which is synonymous with the Wasatch Group, and has a 
thickness of 5,000 feet. It is succeeded by the Lower Green River 
Group, consisting of shales, often bituminous; sandstones; carbonace- 
ous shales and lignitic coal near the base. Thickness, 800 feet. 
This group is well exposed along Green river, from Green River 
station southward for 10 miles; in many of the escarpments of the Quien 
Hornet mountain, and a few miles northeast from the head of Ver- 
milion canon; on Snake river, six miles above the northern foot of 
Junction mountain; and on the elevated ledges known as Pine Bluffs, 
near the sources of the eastern tributaries of Vermilion creek. The 
beds are all fresh water. 
The Upper Green River Group consists of sandstones, sometimes 
argillaceous limestones, carbonaceous shales and lignitic coal, near the 
middle and in the lower part massive or irregularly bedded sandstone, 
ferruginous. Unconformable by erosion with lower Group. Thickness, 
500 feet. 
The plant beds of this group are well exposed to the north of Green 
_ River station, and between that point and Alkali stage station, in 
many gulches and canons; in the cuts of the Union Pacific Railroad 
* Geo. of N. Carolina. 
+ Proc. Cal. Acad. Sci., vol. v. 
t Proc. Acad. Nat. Sci. Phil. 
2 Geo- of Uinta Mountains. 
